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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
4
GENERAL DESCRIPTION
The SX8652 is a very low power, high reliability controller for 4-wire and 5-wire resistive touch screens used in PDAs, portable instruments and point-of-sales terminal applications. It features a wide input supply range from 1.65V to 3.7V and low power modes to preserve current when the screen is unintentionally touched. To compute touch screen X-Y coordinates and touch pressure with precision, a low power 12-bit analog-digital converter is activated with the possibility to enable on-chip data averaging processing algorithms to reduce host activity and suppress system noise. The touch screen controller inputs have been specially designed to provide robust on-chip ESD protection of up to 15kV in both HBM and Contact Discharge, and eliminates the need for external protection devices. The SX8652 is controlled by a high speed SPITM serial interface. The SX8652 is available in a 4.0 mm x 3.0 mm 14-DFN package and a 1.5 mm x 2.0 mm wafer level chip scale package (WLCSP) for space conscience applications.
KEY PRODUCT FEATURES
Extremely Low Power Consumption: 23uA@1.8V 8kSPS Superior On-chip ESD Protection 15kV HBM (X+,X-,Y+,Y-) 2kV CDM 25kV Air Gap Discharge 15kV Contact Discharge 300V MM Single 1.65V to 3.7V Supply/Reference 4-Wire or 5-Wire Resistive Touch Screen Interface Integrated Preprocessing Block to Reduce Host Loading and Bus Activity Four User Programmable Operation Modes provides Flexibility to address Different Application Needs Manual, Automatic, Pen Detect, Pen Trigger Low Noise Ratiometric Conversion Precision, High Speed 12-bit SAR ADC Operating At 74k SPS Throughput: 5000 (X-Y) coordinates/second (c/s) with 7Sample Averaging Low Power Shut-Down Mode < 1uA SPITM Serial Interface Touch Pressure Measurement (4-Wire) Auxiliary Input (4-Wire) For Alternate ADC Input or Start of Conversion Trigger Hardware & Software reset -40 to +85C operation C
Marking FG97 FG97
APPLICATIONS
DSC, DVR, Cell Phones PDA, Pagers Point-of-Sales Terminals Touch-Screen Monitors
ORDERING INFORMATION
Part Number SX8652ICSTRT1 SX8652IWLTRT1
1. 3000 Units / reel
Package (Dimension in mm) 12 - Ball WLCSP (1.5x2.0) 14 - Lead DFN (4.0x 3.0)
Pb-Free, Halogen Free, RoHS/WEEE compliant product Windows CE 6.0, Linux Driver Support Available Packages: 14-LD (4.0 mm x 3.0 mm) DFN 12-Ball (1.5 mm x 2.0 mm) WLCSP
VDD C o ntrol
S X 865 2
N IR Q
VDD
A U X /W IP E R POR N R S T (D FN only) SPI Touch S creen Interface ref+ V ref in refA D C out OSC S C LK D igital Filter DOUT D IN NCS X + /B R Y + /TR X -/TL Y -/B L
T o the touch screen
T o the H o st
GND
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SX8652
ADVANCED COMMUNICATIONS & SENSING Table of contents
Section Page
DATASHEET
1.
General Description ................................................................................................................................................. 4 1.1. 1.2. 1.3. 1.4. DFN Pinout Diagram and Marking Information (Top View).............................................................................. 4 WLCSP Pinout Diagram and Marking Information (Top View) ........................................................................ 4 Pin Description................................................................................................................................................. 5 Simplified Block Diagram ................................................................................................................................. 5 Absolute Maximum Ratings ............................................................................................................................. 6 Recommended Operating Conditions.............................................................................................................. 6 Thermal Characteristics ................................................................................................................................... 6 Electrical Specifications ................................................................................................................................... 7 Host Interface Specifications ........................................................................................................................... 9 Host Interface Timing Waveforms.................................................................................................................... 9 General Introduction ..................................................................................................................................... 10 Channel Pins................................................................................................................................................. 11 X+/BR, X-/TL, Y+/TR. Y-/BL.................................................................................................................... 11 AUX/WIPER ............................................................................................................................................ 11 NIRQ ....................................................................................................................................................... 11 NRST ...................................................................................................................................................... 12
2.
Electrical Characteristics ......................................................................................................................................... 6 2.1. 2.2. 2.3. 2.4. 2.5. 2.6.
3.
Functional Description ........................................................................................................................................... 10 3.1. 3.2.
3.2.1. 3.2.2. 3.3. 3.3.1. 3.3.2. 3.4. 4. 4.1. 4.2. 4.3. 4.4. 5. 5.1. 5.2. 5.3. 6. 6.1.
Host Interface and Control Pins ..................................................................................................................... 11
Power Management Pins............................................................................................................................... 12 Touch Screen Operation................................................................................................................................ 13 Coordinates Measurement............................................................................................................................. 14 Pressure Measurement.................................................................................................................................. 14 Pen Detection ................................................................................................................................................ 15 Touch Screen Operation................................................................................................................................ 16 Coordinates Measurement............................................................................................................................. 16 Pen Detection ................................................................................................................................................ 17 Host Interface and Control ............................................................................................................................. 17 SPI Read/Write Registers ....................................................................................................................... 18 SPI Reading Channel Data ..................................................................................................................... 18 Multiple Read/Write ................................................................................................................................. 18 SPI Host Commands............................................................................................................................... 19 Invalid Qualified Data .............................................................................................................................. 20
4-wire Touch Screen Detailed Description ............................................................................................................ 13
5-wire Touch Screen Detailed Description ............................................................................................................ 16
Data Processing .................................................................................................................................................... 17 6.1.1. 6.1.2. 6.1.3. 6.1.4. 6.1.5. 6.2. 6.3.
Register Map................................................................................................................................................. 21 Host Control Writing ...................................................................................................................................... 22
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SX8652
ADVANCED COMMUNICATIONS & SENSING Table of contents
Section Page
DATASHEET
6.4. 6.5. 7. 7.1. 7.2. 7.3. 7.4. 8. 8.1. 8.2. 8.3.
Power-Up ....................................................................................................................................................... 24 Reset.............................................................................................................................................................. 24 Manual Mode ................................................................................................................................................. 25 Automatic mode ............................................................................................................................................. 25 PENDET Mode .............................................................................................................................................. 26 PENTRIG Mode ............................................................................................................................................. 26 Acquisition Setup ........................................................................................................................................... 27 Channel Selection.......................................................................................................................................... 27 Noise Reduction............................................................................................................................................. 27 POWDLY................................................................................................................................................. 27 SETDLY .................................................................................................................................................. 28 AUX Input ................................................................................................................................................ 28
Modes of Operation .............................................................................................................................................. 24
Application Information .......................................................................................................................................... 27
8.3.1. 8.3.2. 8.3.3. 8.4. 8.5.
Interrupt Generation....................................................................................................................................... 28 Coordinate Throughput Rate ......................................................................................................................... 28 SPI Communication Time ....................................................................................................................... 28 Conversion Time ..................................................................................................................................... 29 AUTO MODE .......................................................................................................................................... 29
8.5.1. 8.5.2. 8.5.3. 8.6. 9. 9.1. 9.2.
ESD event...................................................................................................................................................... 29 DFN Package................................................................................................................................................. 30 WLCSP Package ........................................................................................................................................... 31
Packaging Information ........................................................................................................................................... 30
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 1. General Description
1.1. DFN Pinout Diagram and Marking Information (Top View)
AUX/ WIPER VDD X+/BR Y+/TR X-/TL Y-/BL GND
1 2 3 4 5 6 7 15
14 13 12 11 10 9 8
(NC) NRST NCS NIRQ DOUT DIN SCLK
PIN 1 IDENTIFIER
Figure 1. SX8652 DFN Top View, Pad on Bottom Side
YYWW: date code XXXXX: Lot Number
FG97 YYWW XXXXX
1.2. WLCSP Pinout Diagram and Marking Information (Top View)
X+/BR Y+/TR X-/TL Y-/BL
3
VDD NCS DIN GND
2
AUX/WIPER #
NIRQ
DOUT
SCLK
FG97 YYWW XXXXXX
BALL A1 IDENTIFIER
1 A B C D
Figure 2. SX8652 WLCSP Top View, Solder Bumps on Bottom Side
YYWW: date code XXXXX: Lot Number
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
1.3. Pin Description
Pin Number # DFN WLCSP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 A1 A2 A3 B3 C3 D3 D2 D1 C2 C1 B1 B2 AUX/WIPER Digital Input / Analog Input VDD X+/BR Y+/TR X-/TL Y-/BL GND SCLK DIN DOUT NIRQ NCS NRST (NC) GND Power input Power Input Analog IO Analog IO Analog IO Analog IO Ground Digital Input Digital Output Digital Output Conversion Synchronization (4-wire) or Analog Auxiliary Input (4-wire) / Wiper Input (5-wire) Input power supply, connect to a 0.1uF capacitor to GND X+ Right electrode (4-wire) / Bottom Right (5-wire) channel Y+ Top electrode (4-wire) /Top Right (5-wire) channel X- Left electrode (4-wire) /Top Left (5-wire) channel Y- Bottom electrode (4-wire) /Bottom Left (5-wire) channel Ground SPI Serial Clock Input SPI Serial Data Input SPI Serial Data Output Name Type Description
Digital Output, open drain Interrupt Request Output, Active low, Need external pullup Digital Input Digital Input SPI Chip Select Input, Active low DFN package only, Reset Input, Active low, Internal pull-up resistor Not Connected Backside Ground
Table 1. Pin description
1.4. Simplified Block Diagram
The SX8652 simplified block diagram is shown in Figure 3.
VDD Control NIRQ AUX/WIPER POR NRST (DFN only) SPI Touch Screen Interface Vref OSC SCLK ref+ in ADC out refDigital Filter DOUT DIN NCS X+/BR Y+/TR X-/TL Y-/BL VDD
SX8652
To the touch screen
To the Host
GND
Figure 3. Simplified block diagram of the SX8652
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 2. Electrical Characteristics
2.1. Absolute Maximum Ratings
Stresses above the values listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these, or any other conditions beyond the "Recommended Operating Conditions", is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameter Supply Voltage Input voltage (non-supply pins) Input current (non-supply pins) Operating Junction Temperature Reflow temperature Storage temperature High ESD pins: X+/BR, X-/TL, Y+/TR, Y-/BL, Aux/Wiper All pins except high ESD pins ESD (Contact Discharge) Latchup(iii) High ESD pins: X+/BR, X-/TL, Y+/TR, Y-/BL, Aux/Wiper Symbol VDDABS VIN IIN TJCT TRE TSTOR ESDHBM1 ESDHBM2 ESDCD ILU -50 15(i) 8(ii) 2 15 100 Min. -0.5 -0.5 Max. 3.9 3.9 10 125 260 150 Unit V V mA C C C kV kV kV kV mA
ESD HBM (Human Body Model)
Table 2. Absolute Maximum Ratings
(i) Tested to TLP (10A) (ii) Tested to JEDEC standard JESD22-A114 (iii) Tested to JEDEC standard JESD78
2.2. Recommended Operating Conditions
Parameter Supply Voltage Ambient Temperature Range
Symbol
VDD TA
Min.
1.65V -40
Max
3.7 85
Unit
V C
Table 3. Recommended Operating Conditions
2.3. Thermal Characteristics
Parameter Thermal Resistance with DFN package - Junction to Ambient (iii) Thermal Resistance with WLCSP package - Junction to Ambient (iii)
Symbol
JA JA
Min.
Max
39 65
Unit
C/W C/W
Table 4. Thermal Characteristics
(iii) JA is calculated from a package in still air, mounted to 3" x 4.5", 4 layer FR4 PCB with thermal vias under exposed pad (if applicable)
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
2.4. Electrical Specifications
All values are valid within the recommended operating conditions unless otherwise specified.
Parameter
Symbol
Conditions
Min.
Typ
Max
Unit
Current consumption
Mode = MANUAL Ipwd Converter stopped, pen detection off, SPI listening, OSC stopped Converter stopped, pen detection activated, device generates interrupt upon detection, SPI listening, OSC stopped Converter stopped, pen detection activated, device starts conversion upon pen detection. SPI listening, OSC stopped Converter stopped, pen detection off, SPI listening, OSC on, timer on 0.4 1 uA
Mode = PENDET
Ipndt
0.4
1
uA
Mode =PENTRIG
Ipntr
0.4
1
uA
Mode=AUTO
Iauto
1.5
uA
Operation @8kSPS, VDD=1.8V
Iopl
23 105
50 140
uA uA
Operation @42kSPS, VDD=3.3V Ioph
Digital I/O
High-level input voltage Low-level input voltage VIH VIL VHysLow Hysteresis VHysHigh Output Logic High Output Logic Low Input leakage current High ESD Input - Output capacitance VOH VOL LI CX+/BR ,CX-/TL ,CY+/TR , CY-/BL, CAUX CNRST , CNIRQ ,CNCS ,CDIN , CDOUT, CSCLK VDD < 2V IOL<-4mA IOL<4mA CMOS input 50 0.8VDD 0 0.4 1 V uA pF 0.1 VDD V VDD > 2V 0.8VDD VSS-0.3 0.05 VDD VDD+0.2 0.2VDD V V V
Input - Output capacitance
5
pF
Table 5. Electrical Specifications
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15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
Parameter
Symbol
Conditions
Min.
Typ
Max
Unit
Startup
Power-up time tpor Time between rising edge VDD and rising NIRQ 1 ms
ADC
Resolution Offset Gain error Differential Non Linearity Integral Non Linearity Ares Aoff Age Adnl Ainl At full scale 12 1 0.5 1 1.5 bits LSB LSB LSB LSB
Resistors
X+, X-, Y+, Y- resistance Pen detect resistance Rchn RPNDT_00 RPNDT_01 RPNDT_10 RPNDT_11 Touch Pad Biasing Resistance RPNDT = 0 RPNDT = 1 RPNDT = 2 RPNDT = 3 5 100 200 50 25 Ohm kOhm kOhm kOhm kOhm
External components
Capacitor between VDD, GND Cvdd
recommendations
Type 0402, tolerance +/-50% 0.1 uF
Table 5. Electrical Specifications
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
2.5. Host Interface Specifications
Parameter SPI TIMING SPECIFICATIONS (i) SCLK Clock Frequency Duty Cycle NCS edge to first SCLK "" NCS edge to DOUT Low SCLK High Pulse Width SCLK Low Pulse Width Data Setup Time Data Valid to SCLK Hold Time Data Output Delay after SCLK "" NCS "" to SCLK Ignored NCS "" to DOUT Hi-Z state NCS Hold Time fSCLK duty TCSS TDCD TCKH TCKL TDS TDH TDOD TCSI TCCZ TCSW 150 50 90 80 80 40 70 70 ns 5000 60 kHz % Symbol Condition Min Typ Max Unit
40 50
100
Table 6. Host Interface Specifications
(i) All timing specifications refer to voltage levels (50% VDD, VOH, VOL) defined in Table 6 unless otherwise mentioned.
2.6. Host Interface Timing Waveforms
tCSW CSN tCSS SCLK tDH tDS DIN tDCD DOUT D11 tCCZ VOH VOL 50%VDD tCKL tCKH tDOD tCSI 50%VDD 50%VDD
Figure 4. SPI Timing Waveform
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 3. Functional Description
3.1. General Introduction
This section provides an overview of the SX8652 architecture, device pinout and a typical application. The SX8652 is designed for 4-wire and 5-wire resistive touch screen applications. The touch screen or touch panel is the resistive sensor and can be activated by either a finger or stylus. As shown in Figure 5 with a 4-wire panel, the touch screen coordinates and touch pressure are converted into SPI format by the SX8652 for transfer to the host. The auxiliary input can be used to convert with 12-bit resolution any analog input in the supply range. It can also serves as an external synchronisation input to trig the touchscreen acquisition as described in the Application Information section.
VDD
SX8652
Control NIRQ
VDD
HOST
INT
4-wire touchscreen
AUX/WIPER
POR X-/TL Y+/TR Y-/BL X+/BR Vref SPI Touch Screen Interface OSC
NRST (DFN only) NCS SCLK
DIO CS
SPI Interface
SCLK MISO MOSI
ref+ in ADC out ref-
Digital Filter
DOUT DIN
GND
Figure 5. SX8652 with a 4-wire touch screen
A 5-wire touchscreen application is shown in Figure 6. In this application, the touch pressure can not be calculated.
5-wire touchscreen
VDD Control
SX8652
NIRQ
VDD
HOST
INT
AUX/WIPER POR X-/TL Y+/TR Y-/BL X+/BR Vref SPI Touch Screen Interface OSC SCLK ref+ in ADC out refDigital Filter DOUT DIN NRST (DFN only) NCS DIO CS
SPI Interface
SCLK MISO MOSI
GND
Figure 6. SX8652 with a 5-wire touch screen
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
3.2. Channel Pins
3.2.1. X+/BR, X-/TL, Y+/TR. Y-/BL
VDD
X+ XY+ Y-
The SX8652's channel pins directly connect to standard touch screen X and Y resistive layers. The SX8652 separately biases each of these layers and converts the resistive values into (X,Y) coordinates.
Rchn
Touch Screen Interface
The channel pins are protected to VDD and GROUND. Figure 7 shows the simplified diagram of the X+, X-, Y+, Y- pins.
Figure 7. Simplified diagram of touchscreen pins 3.2.2. AUX/WIPER
VDD ADC
The AUX/WIPER has 2 functions. With 4-wire touchscreen, it is a single ended input for the 12 bit ADC with an input range from GND to VDD. It can also be used to start the channel acquisition. With 5-wire touchscreen, it is the sense channel of the touchpanel.
Control
AUX
The AUX/WIPER pin is protected to VDD and GROUND. Figure 8 shows a simplified diagram of this pin.
Figure 8. Simplified diagram of AUX/WIPER pin
3.3. Host Interface and Control Pins
The SX8652 host and control interface consists of the SPI interface with NIRQ and NRST.
3.3.1. NIRQ
HOST VDD
The NIRQ pin is an active low, open drain output to facilitate interfacing to different supply voltages and thus requires an external pull-up resistor (1-10 kOhm). NIRQ provides an interrupt to the host processor when a pen is detected, or when channel data is available.
IRQ Control
NIRQ
As shown in Figure 9, the NIRQ pin does not have protection to VDD.
Figure 9. Simplified diagram of NIRQ
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
3.3.2. NRST
The NRST pin is an active low input that provides a hardware reset of the SX8652's control circuitry. The NRST pin is protected to GROUND and have an internal pull-up to enable interfacing with devices at different supply voltages.
VDD
Control
NRST
Figure 10 shows a simplified diagram of the NRST pin.
Figure 10. Simplified diagram of NRST
3.4. Power Management Pins
VDD
VDD and GND are power pins. The VDD has ESD protection to GROUND. The GND has ESD protection to VDD. Figure 11 shows a simplified diagram of the VDD pin.
VDD
Power Management
GND
Figure 11. Simplified diagram of VDD and GND
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 4. 4-wire Touch Screen Detailed Description
4.1. Touch Screen Operation
A 4-wire resistive touch screen consists of two (resistive) conductive sheets separated by an insulator when not pressed. Each sheet is connected through 2 electrodes at the border of the sheet (Figure 12). When a pressure is applied on the top sheet, a connection with the lower sheet is established. Figure 13 shows how the Y coordinate can be measured. The electrode plates are connected through terminals X+, X- and Y+, Y- to an analog to digital converter (ADC) and a reference voltage. The resistance between the terminals X+ and X- is defined by Rxtot. Rxtot will be split in 2 resistors, R1 and R2, in case the screen is touched. The resistance between the terminals Y+ and Y- is represented by R3 and R4. The connection between the top and bottom sheet is represented by the touch resistance (RT).
Y+ electrodes
top conductive sheet YX+
electrodes
X-
bottom conductive sheet
Figure 12. 4-wire Touch Screen
Y+ R3 R2
RT
+ Vref -
X-
R1 X+ + ADC Ypos
R4 YFigure 13. Touch Screen Operation ordinate measurement (Y)
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15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
4.2. Coordinates Measurement
The top resistive sheet (Y) is biased with a voltage source. Resistors R3 and R4 determine a voltage divider proportional to the Y position of the contact point. Since the converter has a high input impedance, no current flows through R1 so that the voltage X+ at the converter input is given by the voltage divider created by R3 and R4. The X coordinate is measured in a similar fashion with the bottom resistive sheet (X) biased to create a voltage divider by R1 and R2, while the voltage on the top sheet is measured through R3. Figure 14 shows the coordinates measurement setup. The resistance RT is the resistance obtained when a pressure is applied on the screen. RT is created by the contact area of the X and Y resistive sheet and varies with the applied pressure.
Ypos
X+ R1
RT
Y+ R3 R4 YR2 = 4095 ------------------R1 + R2
X+ R1 + Vref + Vref RT
Y+ R3 R4 Y-
Xpos
R2 X-
R2 X-
Figure 14. Ordinate (Y) and abscissa (X) coordinates measurement setup
The X and Y position are found by: Xpos
R4 Ypos = 4095 ------------------R3 + R4
4.3. Pressure Measurement
The pressure measurement consists of two additional setups: z1 and z2 (see Figure 15).
X+ R1 + Vref RT
Y+ R3 R4
z1 + Vref z2
X+ R1
RT
Y+ R3 R4 Y-
R2 X-
R2 X-
Y-
Figure 15. z1 and z2 pressure measurement setup
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15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
The corresponding equations for the pressure:
R4 z1 = 4095 -------------------------------R1 + R4 + R T
R4 + Rt z2 = 4095 -------------------------------R1 + R4 + R T
The X and Y total sheet resistance (Rxtot, Rytot) are known from the touch screen supplier.
Rxtot = R1 + R2 Rytot = R3 + R4 R4 is proportional to the Y coordinate. The R4 value is given by the total Y plate resistance multiplied by the fraction of the Y Ypos R4 = Rytot ----------position over the full coordinate range. 4095 z2 R T = R4 ---- - 1 By re-arranging z1 and z2 one obtains z1 Ypos R T = Rytot ----------- 4095 z2 ---- - 1 z1
Which results in:
The touch resistance calculation above requires three channel measurements (Ypos, z2 and z1) and one specification data (Rytot).An alternative calculation method is using Xpos, Ypos, one z channel and both Rxtot and Rytot shown in the next calculations R1 is inverse proportional to the X coordinate.
Xpos R1 = Rxtot 1 - -----------4095 Substituting R1 and R4 into z1 and rearranging terms Rytot Y pos 4095 Xpos R T = ------------------------------ ----------- - 1 - Rxtot 1 - -----------gives: 4095 z1 4095 4.4. Pen Detection
RPNDT Y+ X+ R1
Rb Sb PDIRQ
The pen detection circuitry is used both to detect a user action and generate an interrupt or start an acquisition in PENDET and PENTRG mode respectively. Doing a pen detection prior to conversion avoids feeding the host with dummy data and saves power. If the touchscreen is powered between X+ and Y- through a resistor RPNDT, no current will flow so long as pressure is not applied to the surface (see Figure 16). When some pressure is applied, a current path is created and brings X+ to the level defined by the resistive divider determined by RPNDT and the sum of R1, RT and R4. Due to the capacitive loading of the touchscreen, the bias delay is of 0.25 x POWDLY.
+ Vref
-
R3 RT R4
R2
Y-
X-
Figure 16. Pen detection
The resistor RPNDT can be configured to 4 different values (see Table 13) to accommodate different screen resistive values. RPNDT should be set to a value greater than 7x(Rxtot + Rytot). The pen detection will set the PENIRQ bit of the RegStat register. In PENDET mode, the pen detection will set NIRQ low. The PENIRQ bit will be cleared and the NIRQ will be de-asserted as soon as the host reads the status register.
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 5. 5-wire Touch Screen Detailed Description
5.1. Touch Screen Operation
A 5-wire resistive touch screen consists of two (resistive) conductive sheets separated by an insulator when not pressed. 4 wires are connected on the 4 corners of the bottom conductive sheet. They are referred as Top Left, Top Right, Bottom Left, Bottom Right. The fifth wire is used for sensing the electrode voltage and is referred as the wiper. It is embedded in the top sheet. Higher reliability and better endurance are the advantages of 5-wire touchscreen. On the other hand, 5-wire touchscreen does not permit pressure measurement.
top conductive sheet wiper electrodes
TR TL BR BL
electrodes
bottom conductive sheet
5.2. Coordinates Measurement
Linearisation pattern
Figure 17. 5-wire touchscreen
The top resistive sheet is biased with a voltage source. Resistors R3 and R4 determine a voltage divider proportional to the Y position of the contact point. Since the converter has a high input impedance, no current flows through R1 so that the voltage X+ at the converter input is given by the voltage divider created by R3 and R4. The X coordinate is measured in a similar fashion with the bottom resistive sheet biased to create a voltage divider by R1 and R2, while the voltage on the top sheet is measured through R3. Figure 18 shows the coordinates measurement setup.
TL TR W ip e r R3 R4 BL BR
The X and Y position are found by: Xpos
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BR TR + V re f R1 + V re f R2 W ip e r
Ypos
Xpos
BL TL
R4 Ypos = 4095 ------------------R3 + R4
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Figure 18. Ordinate (Y) and abscissa (X) coordinates measurement setup
R2 = 4095 ------------------R1 + R2
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SX8652
15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET
5.3. Pen Detection
The pendetect pull-up resistor and detector continue to monitor the X+/BR pin as in 4-wire mode. The wiper panel is grounded at the AUX_WIPER pin to provide the grounding path for a screen touch event. If a pressure is applied to the surface, a current path is created and will bias the touchscreen between BR and the wiper probe.
6. Data Processing
NFILT
Preprocessing
The SX8652 offers 4 types of data processing which allows the user to make trade-offs between data throughput, power consumption and noise rejection.
ADC
cn,cn-1,cn-2,... Sort: .>.>.>.>.
sn
1 sn = cn-i N i=0
N-1
SPI
The parameter FILT is used to select the filter order Nfilt as seen in Table 7. The noise rejection will be improved with a high order to the detriment of the power consumption.
Figure 19. Filter structure
. FILT
0
Nfilt
1
Processing sn = cn
No average.
1
3
1 4079 -- ----------n = 3 4095 ( c n + c n - 1 + c n - 2 ) 3 ADC samples are averaged 1 4079 s n = -- ----------- ( c n + c n - 1 + c n - 2 + c n - 3 + c n - 4 )
5 4095
2
5
5 ADC samples are averaged
3 7
c max1 c max2 c a c b c c c min1 c min2 1 4079 -- ----------n = 3 4095 ( c a + c b + c c ) 7 ADC samples are sorted and the 3 center samples are averaged
Table 7. Filter order
6.1. Host Interface and Control
The host interface consists of SPI (DIN, DOUT, SCLK, NCS) and the NIRQ, NRST signals. The SPI implemented on the SX8652 is set to the common setting CPOL=0 and CPHA=0. It means data are sampled on the rising edge of the clock, and shifted on the falling one. The default state of the clock when NCS gets asserted is low. If a host send a command while the system is busy, the command is discarded. The supported SPI access formats are described in the next sections:
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Read/Write Registers Read Channels Data Host Commands
6.1.1. SPI Read/Write Registers
The host can write to and read from registers of the SX8652 by the write and read commands as defined in Table 8. W/R command name 7
WRITE(RA) READ(RA) 0 0
CR(7:0) 6
0 1
Function 2
RA(4:0) RA(4:0)
5
0 0
4
3
1
0
Write register (see Table 12 for RA) Read register (see Table 12 for RA)
Table 8.
W/R commands
With the WRITE command, the host can write a single or multiple registers in the SX8652 register. This command is generated by setting the CMD(7:5) bits to write command (000). The register address is latched after the address is received and used for the first write. With the READ command the host can read a single or multiple registers in the SX8652 register file. The frame starts by issuing a write command indicating the address of the first register to be read and the data are put on the DOUT line.
6.1.2. SPI Reading Channel Data
W/R command name 7
READCHAN 0
CR(7:0) 6
0
Function 2
x
5
1
4
x
3
x
1
x
0
x Read Channel Data
Table 9.
Read Channels Data
The data read process is the same as the register read process, but with a different command. Channel data are stored in a FIFO stack with the order: First: X,Y, Z1, Z2, Last: AUX. It is not possible to read two times the same coordinate. When the channel data buffer gets empty, the data will carry an invalid data as explained in the channel data format. For example, if the value 0xC0 is set in RegChanMsk (X and Y conversion), the first READCHAN command will read X value, the second will read Y value and the third one will get invalid data. The channel data D(11:0) is of unsigned format and corresponds to a value between 0 and 4095. This is send on 2 bytes of 8 bits. A mask with the value 0x0FFF (4095) must be done to get correct values.
6.1.3. Multiple Read/Write
The SPI protocol is designed to be able to do multiple read/write during a transaction. During one single operation, as long as NCS stay asserted, the register address is automatically increased to allow sequential read/write (or sequential retrieval of data). Between each different operation though (READ/WRITE/READCHAN), the communication should be restarted. This is described in Figure 20.
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6.1.4. SPI Host Commands
.The host can issue commands to change the operation mode or perform manual actions as defined in Table 10. command name 7
SELECT(CHAN) CONVERT(CHAN) 1 1
CR(7:0) 6
0 0
Function 2 1
CHAN(2:0) CHAN(2:0)
5
0 0
4
0 1
3
x x
0
Bias channel (see Table 11 for CHAN) Bias channel (see Table 11 for CHAN) Wait POWDLY settling time Run conversion x x x Enter manual or automatic mode. Enter pen detect mode. Enter pen trigger mode.
MANAUTO PENDET PENTRG
1 1 1
0 1 1
1 0 1
1 0 0
x x x
x x x
x x x
Table 10.
The channels are defined in Table 11 . Channel 2
X Y Z1 Z2 AUX reserved reserved SEQ 0 0 0 0 1 1 1 1
Host Commands
CHAN(2:0) 1
0 0 1 1 0 0 1 1
Function 0
0 1 0 1 0 1 0 1 Channel sequentially selected from RegChanMsk register, (see Table 13) X channel Y channel First channel for pressure measurement Second channel for pressure measurement Auxiliary channel
Table 11. Channel definition
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Writing Register CS SCLK DIN DOUT Reading Register CS SCLK DIN DOUT Reading Channel Data CS SCLK DIN
001 11 10 9 8 7 6 5 4 3 2 1 0 11 10 9 8 7 6 5 4 3 2 1 0 010 000
Single Read
Multiple Read
RA[4:0]
76543210
76543210
Single Read
Multiple Read
RA[4:0]
76543210 76543210
Single Read
Multiple Read
DOUT Other command CS SCLK DIN DOUT
CMD
Don't care bit Single read Multiple read
Figure 20. Data channel format
6.1.5. Invalid Qualified Data
The SX8652 will return 0xFFFF data in case of invalid qualified data. This occurs: When the SX8652 has read all the channel data in the FIFO When a conversion is done without a pen being detected.
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6.2. Register Map
Register Address RA(4:0)
0 0000 0 0001 0 0010 0 0100 0 0101 1 1111
Register
RegCtrl0 RegCtrl1 RegCtrl2 RegChanMsk RegStat RegSoftReset
Description
Write, Read Write, Read Write, Read Write, Read Read Write
Table 12.
Register address
The details of the registers are described in the next sections.
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6.3. Host Control Writing
Register Bits Default Description
Set rate in coordinates per sec (cps) ( 20%) If RATE equals zero then Manual mode. if RATE is larger than zero then Automatic mode 0000: Timer disabled -Manual mode 0001: 10 cps 0010: 20 cps 0011: 40 cps 0100: 60 cps 0101: 80 cps 0110: 100 cps 0111: 200 cps 1000: 300 cps 1001: 400 cps 1010: 500 cps 1011: 1k cps 1100: 2k cps 1101: 3k cps 1110: 4k cps 1111: 5k cps
7:4
0000
RATE
RegCtrl0
Settling time ( 10%): The channel will be biased for a time of POWDLY before each channel conversion 0000: Immediate (0.5 us) 0001: 1.1 us 0010: 2.2 us 0011: 4.4 us 0100: 8.9 us 0101: 17.8 us 0110: 35.5 us 0111: 71.0 us 00: AUX is used as an analog input (4-wire only) 01: On rising AUX edge, wait POWDLY and start acquisition 1000: 0.14 ms 1001: 0.28 ms 1010: 0.57 ms 1011: 1.14 ms 1100: 2.27 ms 1101: 4.55 ms 1110: 9.09 ms 1111: 18.19 ms 10: On falling AUX edge, wait POWDLY and start acquisition 11: On rising and falling AUX edges, wait POWDLY and start acquisition
3:0
0000
POWDLY
7:6
00
AUXAQC
The AUX trigger works only in manual mode with 4-wire touchscreen Enable conditional interrupts 0: interrupt always generated at end of conversion cycle. If no pen is detected the data is set to `invalid qualified'. 1: interrupt generated when pen detect is successful Select the type of screen: 0: 4-wire 1: 5 -wire Select the Pen Detect Resistor 00: 100 kOhm 01: 200 kOhm 10: 50 kOhm 11: 25 kOhm Digital filter control 00: Disable 01: 3 sample averaging 10: 5 sample averaging 11: 7 sample acquisition, sort, average 3 middle samples
5
1
CONDIRQ
RegCtrl1
4
0
SCREEN
3:2
00
RPDNT
1:0
00
FILT
Table 13. SX8652 Register
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Register Bits
7:4
Default
0 reserved
Description
Settling time while filtering ( 10%) When filtering is enabled, the channel will initially bias for a time of POWDLY for the first conversion, and for a time of SETDLY for each subsequent conversion in a filter set.
RegCtrl2
3:0 0000 SETDLY
0000: Immediate (0.5 us) 0001: 1.1 us 0010: 2.2 us 0011: 4.4 us 0100: 8.9 us 0101: 17.8 us 0110: 35.5 us 0111: 71.0 us 0: no sample 1: Sample X channel 0: no sample 1: Sample Y channel 0: no sample 1: Sample Z1 channel 0: no sample 1: Sample Z2 channel 0: no sample 1: Sample AUX channel
1000: 0.14 ms 1001: 0.28 ms 1010: 0.57 ms 1011: 1.14 ms 1100: 2.27 ms 1101: 4.55 ms 1110: 9.09 ms 1111: 18.19 ms
7 6 5 4 3 0 0 0
1 1 0 0 0 0 0 0
XCONV YCONV Z1CONV Z2CONV AUXCONV reserved reserved reserved
RegChanMsk
The host status reading allows the host to read the status of the SX8652. The data goes from the SX8652 towards the host. Host writing to this register is ignored. 7 0 CONVIRQ 0: no IRQ pending 1: Conversion sequence finished IRQ is cleared by the channel data read command Operational in pen detect mode 0: no IRQ pending 1: Pen detected IRQ pending IRQ is cleared by the RegStat reading A reset event has occurred
RegStat
6
0
PENIRQ
5 4:0
1 00000 0x00
RSTEVENT reserved
RegSoftReset
7:0
If the host writes the value 0xDE to this register, then the SX8652 will be reset. Any other data will not affect the SX8652
Table 13. SX8652 Register
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6.4. Power-Up
voltage
The NIRQ pin is kept low during SX8652 power-up. During power-up, the SX8652 is not accessible and SPI communications are ignored.
time
VDD
VDD/2
As soon as NIRQ rises, the SX8652 is ready for SPI communication.
voltage
t POR
NIRQ
time
Figure 21.
Power-up, NIRQ
6.5. Reset
The POR of the SX8652 will reset all registers and states of the SX8652 at power-up. Additionally the host can reset the SX8652 by asserting the NRST pin (active low) and also via the SPI bus. If NRST is driven LOW, then NIRQ will be driven low by the SX8652. When NRST is released (or set to high) then NIRQ will be released by the SX8652. The circuit has also a soft reset capability. When writing the code 0xDE to the register RegSoftReset, the circuit will be reset.
7. Modes of Operation
The SX8652 has four operation modes that are configured using the SPI commands as defined in Table 10 and Table 13. These 4 modes are: manual (command `MANAUTO' and RATE=0), automatic (command `MANAUTO' and RATE>0), pen detect (command `PENDET'), pen trigger mode (command `PENTRG'). At startup the SX8652 is set in manual mode. In the manual mode the SX8652 is entirely stopped except for the SPI peripheral which accepts host commands. This mode requires RATE equal to be zero (RATE = 0, see Table 13). In the automatic mode the SX8652 will sequence automatic channel conversions. This mode requires RATE to be larger than zero (RATE > 0, see Table 13). In the PENDET mode the pen detection is activated. The SX8652 will generate an interrupt (NIRQ) upon pen detection and set the PENIRQ bit in the SPI status register. To quit the PENDET mode the host needs to configure the manual mode. In the PENTRG mode the pen detection is activated and a channel conversion will start after the detection of a pen. The SX8652 will generate an interrupt (NIRQ) upon pen detection and set the CONVIRQ bit in the SPI status register. To quit the PENTRIG mode the host needs to configure the manual mode. The PENTRG mode offers the best compromise between power consumption and coordinate throughput.
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7.1. Manual Mode
In manual mode (RATE=0) single actions are triggered by the SPI commands described in Table 14. When a command is received, the SX8652 executes the associated task and waits for the next command. It is up to the host to sequence all actions. Command
CONVERT(CHAN)
Action
Select and bias a channel Wait for the programmed settling time (POWDLY)
Start conversion
SELECT(CHAN)
Select and bias a channel
Table 14.
CONVERT and SELECT command
The channel can be biased for an arbitrary amount of time by first sending a SELECT command and then a CONVERT command once the settling time requirement is met. The SELECT command can be omitted if the large range of POWDLY settings cover the requirements. In the latter case, the CONVERT command alone is enough to perform an acquisition. With CHAN=SEQ, multiple channels are sampled. This requires programming the POWDLY field in register RegCTRL0. The selected channel will be powered during POWDLY before a conversion is started. The channel bias is automatically removed after the conversion has completed.
7.2. Automatic mode
AUTO MODE
In automatic mode (RATE > 0), SX8652 will automatically decide when to start acquisition, sequence all the acquisitions and alerts the host if data is available for download with a NIRQ. The host will read the channels and the SX8652 will start again with the next conversion cycle. The fastest coordinate rate is obtained if the host reads the channels immediately after the NIRQ.
yes
CONDIRQ=1 ?
To not loose data, the SX8652 will not begin conversion before the host read the channels. If after the NIRQ a delay superior to the sampling period is made by the host to read the channels a slower coordinate rate is obtained. When the control CONDIRQ bit (see register RegStat Table 13) is set to `1' then the interrupts will only be generated if the pen detect occurred. This result in a regular interrupt stream, as long as the host performs the read channel commands, and the screen is touched. When the screen is not touched, interrupts does not occur. If the control CONDIRQ bit is cleared to `0', the interrupts will be always generated. In case there is no pen detected on the screen then the coordinate data will be qualified as invalid, see section [6.1.5]. This result in a regular interrupt stream, as long as the host performs the read channel commands, independent of the screen being touched or not. This working is illustrated in Figure 22.
Touch Detected ?
no
yes Set timer=RATE Start timer Start channel conversion All conversion finished Set interrupt NIRQ=0 All channel data read Release Interrupt NIRQ=1 Timer expire
Figure 22. AUTO Mode Flowchart
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Figure 23 shows the SPI working in automatic mode with CONDIRQ=1. After the first sentence send through the SPI to make the initialization, traffic is reduced as only reads are required. The processing time is the necessary time for the SX8652 to makes the pendetection, the settling time (POWDLY) and the conversion. This time increases with the number of channel selected and the filter used.All succeeding conversions notifies the host by an interrupt signal and the host only needs to issue the SPI read command. The reads occur at the RATE interval.
TOUCH NIRQ CS DIN DOUT Read Channel Data CMD Data from SX8652 Processing time Time is 1/ RATE
Figure 23.
SPI working in AUTO mode
7.3. PENDET Mode
PENDET MODE
The PENDET mode can be used if the host only needs to know if the screen has been touched or not and take from that information further actions. When pen detect circuitry is triggered the interrupt signal NIRQ will be generated and the status register bit `PENIRQ' will be set. The bit is cleared by reading the status register RegStat.
Touch Detected ?
no
yes Set interrupt NIRQ=0 RegStat read Release Interrupt NIRQ=1
Figure 24. PENDET Mode Flowchart
7.4. PENTRIG Mode
The PENTRIG mode offers the best compromise between power consumption and coordinate throughput. In this mode the SX8652 will wait until a pen is detected on the screen and then starts the coordinate conversions. The host will be signalled only when the screen is touched and coordinates are available. The coordinate rate in pen trigger mode is determined by the speed of the host reading the channels and the conversion times of the channels. The host performs the minimum number of SPI commands in this mode. The host has to wait for the NIRQ interrupt to make the acquisition of the data. The flowchart and the SPI working is illustrated in Figure 25.
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PENTRIG MODE
TOUCH
Touch Detected ?
NIRQ
no
yes
CS DIN
Start channel conversion
DOUT
All conversion finished Set interrupt NIRQ=0 All channel data read Release Interrupt NIRQ=1
Read Channel Data CMD Data from SX8652 Conversion time
Figure 25. PENTRIG Mode Flowchart and SPI working in PENTRIG mode
8. Application Information
This section describes in more detail application oriented data.
8.1. Acquisition Setup
Prior to an acquisition, the SX8652 can be setup by writing the control registers. Registers are written by issuing the register write command. They can be read by issuing the read command. Please refer to the section [6.3]. If no registers are written, the circuit will start in manual mode.
8.2. Channel Selection
The SX8652 can be setup to start a single channel conversion or to convert several channels in sequence. For a single conversion, the channel to be converted is determined from the CHAN(2:0) field in the command word (defined in Table 11). Several channels can be acquired sequentially by setting the CHAN(2:0) field to SEQ. The channels will be sampled in the order defined by register RegChanMsk from MSB to LSB. If a "one" is written in a channel mask, the corresponding channel will be sampled, in the opposite case, it is ignored and the next selected channel is chosen.
8.3. Noise Reduction
A noisy environment can decrease the performance of the controller. For example, an LCD display located just under the touch screen can adds a lot of noise on the high impedance A/D converter inputs.
8.3.1. POWDLY
In order to perform correct coordinates acquisition properly, some time must be given for the touch screen to reach a proper level. It is a function of the PCB trace resistance connecting the SX8652 to the touchscreen and also the capacitance of the touchscreen. If tau is this RC time constant then POWDLY duration must be programmed to 10 tau to reach 12 bit accuracy.
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Adding a capacitor from the touch screen drivers to ground is a solution to minimize external noise. A low-pass filter created by the capacitor may increase settling time. Therefore, use POWDLY to stretch the acquisition period. POWDLY can be estimated by the following formula:
PowDly = 10 x Rtouch x Ctouch
Rtouch is the sum of the panel resistances plus any significant series input resistance, Rxtot + Rytot + Ri. Ctouch is the sum of the touch panel capacitance plus any noise filtering and routing capacitances.
8.3.2. SETDLY
A second method of noise filtering uses an averaging filter as described in section [6] (Data processing). In this case, the chip will sequence up to 7 conversions on each channel. The parameter SETDLY sets the settling time between the consecutive conversions. In most applications, SETDLY can be set to 0. In some particular applications, where accuracy of 1LSB is required and Ctouch is less than 100nF a specific value should be determined.
8.3.3. AUX Input
An alternate conversion trigger method can be used with 4-wire touchscreen if the host system provides additional digital signals that indicate noisy or noise-free periods. The SX8652 can be set up to start conversions triggered by the AUX pin. A rising edge, a falling edge or both can trigger the conversion. To enter this mode, AUXACQ must be set to a different value than '00' as defined in Table 13. The AUX edge will first trigger the bias delay (POWDLY). Following the programmed delay, the channel acquisition takes place.
8.4. Interrupt Generation
An interrupt (NIRQ=0) will be generated: During the power-up phase or after a reset After completion of a conversion in MANUAL, PENTRIG or AUTO mode. CONVIRQ (bit [7] of RegStat) will be set at the same time. After a touch on the panel is detected in PENDET mode. PENIRQ (bit [6] of RegStat) will be set at the same time. The NIRQ will be released and pulled high(NIRQ=1) by the external pull-up resistor: When the power-up phase is finished When the host read all channels data that were previously converted by the SX8652 in MANUAL, PENTRIG or AUTO mode. CONVIRQ will be cleared at the same time. When the host read the status register in PENDET mode. PENIRQ, will be cleared at the same time. An active NIRQ (low) needs to be cleared before any new conversions will occur.
8.5. Coordinate Throughput Rate
The coordinate throughput rate depends on the following factors: The SPI communication time: Tcom The conversion time: Tconv
1 The coordinate rate is the frequency to get the X, Y, Z1 and Z2 coordinate: CoordRate = ------------------------------T com + T conv
8.5.1. SPI Communication Time
The minimum time to read the channel data in PENTRIG mode is: T com
= ( 8 + 16 x N chan ) x T SPI
The highest throughput will be obtained with a SPI frequency of 5MHz when the host read the channel data as quickly as possible after the NIRQ falling edge.
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8.5.2. Conversion Time
The maximum possible throughput can be estimated with the following equation
T conv = 47 T osc + N chan [ POWDLY + SETDLY ( N filt - 1 ) + T osc ( 21N filt + 1 ) ]
with: Nfilt = {1,3,5,7} based on the order defined for the filter FILT (see Figure 7). Nchan = {1,2,3,4,5} based on the number of channels defined in RegChanMsk POWDLY = 0.5us to 18.19ms, settling time as defined in RegCtrl0 SETDLY = 0.5us to 18.19ms, settling time when filtering as defined in RegCtrl2 Tosc is the oscillator period (555ns +/- 15%) Table 15 gives some examples of Coordinate Rate and Sample Rate for various setting in PENTRIG mode.
Nch [1..5 ] 2 2 4
Nfilt [1 3 5 7]
1 3 3
PowDly [uS]
0.5 71 140
SetDly [uS]
0.5 0.5
Tconv [uS]
Tcomm [uS]
CoordRate [kSPS]
51 190 740
8 8 14
16.7 5.0 1.3
Table 15. Coordinate throughput examples 8.5.3. AUTO MODE
In AUTO mode, the coordinate throughput rate is the RATE set in RegCtrl0 if the host retrieve channel data at this RATE. The RATE set should be superior or equal to the CoordRate.
8.6. ESD event
In case of ESD event, the chip can reset to protect its internal circuitry. The bit RSTEVENT indicates that a reset event has occurs. ESD event may trig the pen detection circuitry. In this case wrong data will be send to the host. To detect this false coordinates on 4-wire touchscreen, a pressure measurement can be done. The conditions Z1<10 and Z2>4070 indicate an ESD event.
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15kV ESD Low Power 4-Wire / 5-Wire Resistive Touchscreen Controller with SPI Interface ADVANCED COMMUNICATIONS & SENSING DATASHEET 9. Packaging Information
9.1. DFN Package
A
PIN1 INDICATOR (LASER MARK) D
B
DIM
E A A1 A2 b D D1 E E1 e L N aaa bbb
DIMENSIONS MILLIMETERS MIN NOM MAX
0.80 0.70 0.00 0.02 0.05 - (0.20) 0.18 0.25 0.30 3.90 4.00 4.10 3.05 3.20 3.30 2.90 3.00 3.10 1.55 1.70 1.80 0.50 BSC 0.30 0.40 0.50 14 0.08 0.10
A aaa C A1 A2 C LxN D1
12
SEATING PLANE
E/2 E1
N
bxN e D/2
NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS.
bbb
CAB
Figure 26. DFN Package Outline Drawing
DIMENSIONS DIM C G H K P X Y Z MILLIMETERS (2.90) 2.20 1.70 3.30 0.50 0.30 0.70 3.60
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 3. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE.
Figure 27. DFN Package Land Pattern
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9.2. WLCSP Package
A 1.50.10 B
INDEX AREA A1 CORNER
2.00.10
0.10 C 0.625 Max. 0.250.10 C 1.00 0.50 D 0.50 C 1.50 B 0.25 A 1 2 3 12X O.300.05 0.05 CAB 0.08 C SEATING PLANE
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS
Figure 28. WLCSP Package Outline Drawing
1.00 0.50
0.50
0.25 1.50
12X O0.325
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET.
Figure 29. WLCSP Land Pattern of WLCSP
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SX8652
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
(c) S e m te c h 2 0 1 0 A ll rig h ts re s e rv e d . R e p ro d u c tio n in w h o le o r in p a rt is p ro h ib ite d w ith o u t th e p rio r w ritte n c o n s e n t o f th e c o p y rig h t o w n e r. T h e in fo rm a tio n p re s e n te d in th is d o c u m e n t d o e s n o t fo rm p a rt o f a n y q u o ta tio n o r c o n tra c t, is b e lie v e d to b e a c c u ra te a n d re lia b le a n d m a y b e c h a n g e d w ith o u t n o tic e . N o lia b ility w ill b e a c c e p te d b y th e p u b lis h e r fo r a n y c o n s e q u e n c e o f its u s e . P u b lic a tio n th e re o f d o e s n o t c o n v e y n o r im p ly a n y lic e n s e u n d e r p a te n t o r o th e r in d u s tria l o r in te lle c tu a l p ro p e rty rig h ts . S e m te c h a s s u m e s n o re s p o n s ib ility o r lia b ility w h a ts o e v e r fo r a n y fa ilu re o r u n e x p e c te d o p e ra tio n re s u ltin g fro m m is u s e , n e g le c t im p ro p e r in s ta lla tio n , re p a ir o r im p ro p e r h a n d lin g o r u n u s u a l p h y s ic a l o r e le c tric a l s tre s s in c lu d in g , b u t n o t lim ite d to , e x p o s u re to p a ra m e te rs b e y o n d th e s p e c ifie d m a x im u m ra tin g s o r o p e ra tio n o u ts id e th e s p e c ifie d ra n g e . S E M T E C H P R O D U C T S A R E N O T D E S IG N E D , IN T E N D E D , A U T H O R IZ E D O R W A R R A N T E D T O B E S U IT A B L E F O R U S E IN L IF E -S U P P O R T A P P L IC A T IO N S , D E V IC E S O R S Y S T E M S O R O T H E R C R IT IC A L A P P L IC A T IO N S . IN C L U S IO N O F S E M T E C H P R O D U C T S IN S U C H A P P L IC A T IO N S IS U N D E R S T O O D T O B E U N D E R T A K E N S O L E L Y A T T H E C U S T O M E R 'S O W N R IS K . S h o u ld a c u s to m e r p u rc h a s e o r u s e S e m te c h p ro d u c ts fo r a n y s u c h u n a u th o riz e d a p p lic a tio n , th e c u s to m e r s h a ll in d e m n ify a n d h o ld S e m te c h a n d its o ffic e rs , e m p lo y e e s , s u b s id ia rie s , a ffilia te s , a n d d is trib u to rs h a rm le s s a g a in s t a ll c la im s , c o s ts d a m a g e s a n d a tto rn e y fe e s w h ic h c o u ld a ris e . A ll re fe re n c e d b ra n d s , p ro d u c t n a m e s , s e rv ic e n a m e s a n d tra d e m a rk s a re th e p ro p e rty o f th e ir re s p e c tiv e o w n e rs .
Contact information
Semtech Corporation Advanced Communications & Sensing Products
E-mail: sales@semtech.comacsupport@semtech.comInternet: http://www.semtech.com
USA
200 Flynn Road, Camarillo, CA 93012-8790. Tel: +1 805 498 2111 Fax: +1 805 498 3804 12F, No. 89 Sec. 5, Nanking E. Road, Taipei, 105, TWN, R.O.C. Tel: +886 2 2748 3380 Fax: +886 2 2748 3390 Semtech Ltd., Units 2 & 3, Park Court, Premier Way, Abbey Park Industrial Estate, Romsey, Hampshire, SO51 9DN. Tel: +44 (0)1794 527 600 Fax: +44 (0)1794 527 601
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