View ADT7301_974027.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

a
13-Bit, 0.5oC Accurate, MicroPower Digital Temperature Sensor in 6-Lead SOT-23
Preliminary Technical Data
FEATURES 13-Bit Temperature-to-Digital Converter -40 o C to +150 o C Operating Temperature Range Max Temperature of 150 o C 0.5 o C Accuracy 0.03125 o C Temperature Resolution Operating Current of 1 A SPI- and DSP-Compatible Serial Interface Shutdown Mode Space-Saving SOT-23 and microSOIC Packages APPLICATIONS Medical Equipment Automotive Cell Phone Hard Disk Drives Personal Computers Electronic Test Equipment Office Equipment Domestic Appliances Process Control
BANDGAP TEMPERATURE SENSOR GND
ADT7301
FUNCTIONAL BLOCK DIAGRAM
13-BIT ANALOG/DIGITAL CONVERTER VDD
ADT7301
TEMPERATURE VALUE REGISTER
CS SERIAL BUS INTERFACE SCLK DIN DOUT
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The ADT7301 is a complete temperature monitoring system available in SOT-23 and MSOP packages. It contains a bandgap temperature sensor and a 13-bit ADC to monitor and digitize the temperature reading to a resolution of +0.03125C. The ADT7301 has a flexible serial interface that allows easy interfacing to most microcontrollers. The interface is compatible with SPITM, QSPI and MICROWIRETM protocol and is also compatible with DSPs. The part features a standby mode that is controlled via the serial interface. The ADT7301's wide supply voltage range, low supply current and SPI-compatible interface, make it ideal for a variety of applications, including personal computers, office equipment, automotive and domestic appliances.
1. The ADT7301 has an on-chip temperature sensor that allows an accurate measurement of the ambient temperature. The measurable temperature range is -40C to +150C. 2. Supply voltage of +2.7 V to +5.5 V. 3. Space-saving 6-lead SOT-23 and 8-lead microSOIC packages. 4. Temperature accuracy of 0.5C. 4. 13-bit temperature reading to +0.03125C resolution. 5. The ADT7301 features a shutdown mode that reduces the power consumption to 4.88 W with VDD = 3.3 V @ 1 SPS.
REV. Pr. F 08/'03
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
SPI is a trademark of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor, Inc. One Technology Way, P Box 9106, Norwood, MA 02062-9106, U.S.A. .O. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 Analog Devices, Inc., 2003
ADT7301-3.3 -SPECIFICATIONS1
(TA = TMIN to TMAX, VDD = +2.7 V to +5.5 V, unless otherwise noted)
Parameter
TEMPERATURE SENSOR AND ADC
Preliminary Technical Data
Typ Max Units Test Conditions/Comments
Min
Accuracy @ VDD = +3.3 V (10%)
Temperature Resolution Auto Conversion Update Rate, tR Temperature Conversion Time SUPPLIES Supply Voltage Supply Current Normal Mode @ 3.3 V (10%) Shutdown Mode @ 3.3V (10%) Power Dissipation Normal Mode (Average) Shutdown Mode (Average) 3 1 sps 10 sps 100 sps DIGITAL INPUT 4 Input High Voltage, VIH Input Low Voltage, VIL Input Current, IIN Input Capacitance, CIN DIGITAL OUTPUT 4 Output High Voltage, VOH Output Low Voltage, VOL Output Capacitance, COUT 2.4 2.7
tbd tbd tbd tbd 0.03125 1 800
0.5 1 2 32
C C C C C sec s V mA A A W W W W V V A pF
TA TA TA TA
= = = =
0C to -40C -40C -40C
70C. to +85C. to +125C. to +150C.
Temperature measurement every 1 second
5.5 1.6 190 0.2 631 4.88 42.9 423 2.2 300 1
For Specified Performance Powered up and converting Powered up an not converting
VDD = +3.3 V. Auto Conversion Update, tR VDD = +3.3 V - Shutdown Mode VDD = +3.3 V - Shutdown Mode VDD = +3.3 V - Shutdown Mode
0.8 1 10 VDD - 0.3 V 0.4 50
VIN = 0 V to VDD All Digital Inputs ISOURCE = ISINK = 200 A IOL = 200 A
V pF
NOTES 1 All specifications apply for -40C to +150C unless otherwise stated. 2 It is not recommended to operate the device at temperatures above +125C for greater than a total of 5% of the lifetime of the device. Any exposure beyond this limit will affect device reliability. 3 The ADT7301 is taken out of shutdown mode and a temperature conversion is immediately performed after this write operation. Once the temperature conversion is complete the ADT7301 is put back into shutdown mode. 4 Guaranteed by design and characterization, not production tested. Specifications subject to change without notice.
-2-
REV. Pr. F
Preliminary Technical Data
(TA = TMIN to TMAX, VDD = +2.7 V to +5.5 V, unless otherwise noted)
Parameter
TEMPERATURE SENSOR AND ADC
ADT7301-5 -SPECIFICATIONS1
Typ Max Units Test Conditions/Comments
Min
Accuracy @ VDD = +5 V (10%)
Temperature Resolution Autoconversion Update Rate, tR Temperature Conversion Time SUPPLIES Supply Voltage Supply Current Normal Mode @ 5 V (10%) Shutdown Mode @ 5 V (10%) Power Dissipation Normal Mode (Average) Shutdown Mode (Average)3 1 sps 10 sps 100 sps DIGITAL INPUT 4 Input High Voltage, VIH Input Low Voltage, VIL Input Current, IIN Input Capacitance, CIN DIGITAL OUTPUT 4 Output High Voltage, VOH Output Low Voltage, VOL Output Capacitance, COUT 2.4 2.7
tbd tbd tbd tbd 0.03125 1 800
0.5 1 2 32
C C C C C sec s V mA A A mW W W W V V A pF
TA TA TA TA
= = = =
0C to -40C -40C -40C
70C. to +85C. to +125C. to +150C.
Temperature measurement every 1 second
5.5 1.6 280 0.2 1.41 7.4 65 641 2.2 400 1
For Specified Performance Powered up and converting Powered up an not converting
VDD = +5 V. Auto Conversion Update, tR VDD = +5 V - Shutdown Mode VDD = +5 V - Shutdown Mode VDD = +5 V - Shutdown Mode
0.8 1 10 VDD - 0.3 V 0.4 50
VIN = 0 V to VDD All Digital Inputs ISOURCE = ISINK = 200 A IOL = 200 A
V pF
NOTES 1 All specifications apply for -40C to +150C unless otherwise stated. 2 It is not recommended to operate the device at temperatures above +125C for greater than a total of 5% of the lifetime of the device. Any exposure beyond this limit will affect device reliability. 3 The ADT7301 is taken out of shutdown mode and a temperature conversion is immediately performed after this write operation. Once the temperature conversion is complete the ADT7301 is put back into shutdown mode. 4 Guaranteed by design and characterization, not production tested. Specifications subject to change without notice.
REV. Pr.F
-3-
ADT7301
ABSOLUTE MAXIMUM RATINGS 1
Preliminary Technical Data
200 A IOL
VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +7 V Digital Input Voltage to GND . . . . . . . -0.3 V to VDD + 0.3 V Digital Output Voltage to GND . . . . . -0.3 V to VDD + 0.3 V Operating Temperature Range2 . . . . . -40C to +150C Storage Temperature Range . . . . . . . . -65C to +150C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . +150C 6-Lead SOT-23 (RJ-6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Dissipation3 . . . . . . . WMAX = (TJMAX - TA4)/JA Thermal Impedance JA, Junction-to-Ambient (still air) . . . 190.4C/W 8-Lead MSOP (RM-8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power Dissipation3 . . . . . . . WMAX = (TJMAX - TA4)/JA Thermal Impedance5 JA, Junction-to-Ambient (still air) . . . 205.9C/W JC , Junction-to-Case . . . . . . . . . . . . . . 43.74C/W IR Reflow Soldering Peak Temperature . . . . . . . . . . . . +220C (-0/+5C) Time at Peak Temperature . . . . . . . . . . 10 to 20 secs Ramp-up Rate . . . . . . . . . . . . . . . . . . . . . . . 2-3C/sec Ramp-down Rate . . . . . . . . . . . . . . . . . . . . . . -6C/sec
Maximum Power Dissipation - Watts
TO OUTPUT PIN
+1.6V CL 50pF
200 A
I OH
Figure 1. Load Circuit for Data Access Time and Bus Relinquish Time
1.2
1
1
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. It is not recommended to operate the device at temperatures above +125C for greater than a total of 5% of the lifetime of the device. Any exposure beyond this limit will affect device reliability. Values relate to package being used on a standard 2-layer pcb. Reference Figure 2. for a plot of max power dissipation vs. ambient temperature (T A ). T A = Ambient Temperature. Junction-to-Case resistance is applicable to components featuring a preferential flow direction, eg. components mounted on a heat sink. Junction-to-Ambient resistance is more useful for air-cooled PCBmounted components.
0.8
SOT-23 0.6
2
M SOP 0.4
3
0.2
4 5
0 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 120 125 130 140 150 Temperature- C
Figure 2. Plot of Maximum Power Dissipation vs. Temperature
TIMING CHARACTERISTICS1,
Parameter t1 t2 t3 t 44 t5 t6 t7 t 84 Limit 5 25 25 35 20 5 5 40 Units ns ns ns ns ns ns ns ns min min min max min min min max
2, 3
(TA = TMIN to TMAX, VDD = +2.7 V to +5.5 V, unless otherwise noted)
Comments CS to SCLK Setup Time SCLK High Pulsewidth SCLK Low Pulsewidth Data Access Time After SCLK Falling Edge Data Setup Time Prior to SCLK Rising Edge Data Hold Time After SCLK Rising Edge CS to SCLK Hold Time CS to DOUT High Impedance
NOTES 1 Guaranteed by design and characterization, not production tested. 2 All input signals are specified with tr = tf = 5 ns (10% to 90% of V DD) and timed from a voltage level of 1.6 V. 3 See Figure 2. 4 Measured with the load circuit of Figure 1.
-4-
REV. Pr. F
Preliminary Technical Data
PIN FUNCTION DESCRIPTION
ADT7301
Description
Pin Mnemonic GND DIN V DD SCLK
SOT-23 Pin No. 1 2 3 4
CS DOUT
5 6
Analog and Digital Ground. Serial Data Input. Serial data to be loaded to the part's control register is provided on this input. Data is clocked into the control register on the rising edge of SCLK. Positive Supply Voltage, +2.7 V to +5.5 V. Serial Clock Input. This is the clock input for the serial port. The serial clock is used to clock data out of the temperature value register of the ADT7301 and also to clock data into the control register on the part. Chip Select Input. Logic Input. The device is selected when this input is low. The SCLK input is disabled when this pin is high. Serial Data Output. Logic output. Data is clocked out of the temperature value register at this pin. Data is clocked out on the falling edge of SCLK.
PIN CONFIGURATIONS SOT-23
GND 1
6
DOUT CS SCL K
A DT7301
DIN 2 VDD 3
TOP VIEW (Not to Scale)
5 4
MSOP
NC 1
8
NC
ADT7301
DOUT 2 CS
3
TOP VIEW (Not to Scale)
7 GND 6 5
DIN VDD
SCLK 4
ORDERING GUIDE
Model ADT7301-3.3BRT ADT7301-3.3BRM ADT7301-5BRT ADT7301-5BRM
Temperature Range -40C to +150C -40C to +150C -40C to +150C -40C to +150C
Temperature Accuracy* 0.5C 0.5C 0.5C 0.5C
Package Description 6-Lead SOT-23 8-Lead MSOP 6-Lead SOT-23 8-Lead MSOP
Samples Branding Information TCS TCS
Package Option RJ-6 RM-8 RJ-6 RM-8
*Temperature accuracy is over 0C to +70C temperature range.
CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the ADT7301 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
REV. Pr. F
-5-
ADT7301
TYPICAL PERFORMANCE CURVES
0 0
Preliminary Technical Data
TITLE
0
TITLE
0 0 0
0
0
0
0 TITLE
0
0
0
0
0
0
0 TITLE
0
0
0
TPC 1. Temperature Accuracy @ 3.3 V and 5 V
TPC 2. Operating Supply Current vs Temperature
0
0
TITLE
0
TITLE
0 0 TITLE 0 0
0
0
0
0
0
0
0
0
0
0 TITLE
0
0
0
TPC 3. Operating Supply Current vs Supply Voltage
TPC 4. Power-Down Current vs Supply Voltage
0
0
TITLE
0
TITLE
0 0 TITLE 0 0
0
0
0
0
0
0
0
0
0
0 TITLE
0
0
0
TPC 5. Temperature Accuracy vs Supply Ripple Frequency
TPC 6. Response to Thermal Shock
-6-
REV. Pr. F
Preliminary Technical Data
CIRCUIT INFORMATION
ADT7301
ture sensor is guaranteed to a low value limit of -40 C and a high limit of +150 C. The temperature data format is shown in Table I. This table shows the temperature measurement range of the device (-40C to +150C). A typical performance curve is shown in TPC 1.
Table I. Temperature Data Format
The ADT7301 is a 13-bit digital temperature sensor with a 14th bit as a sign bit. The part houses an on-chip temperature sensor, a 13-bit A/D converter, a reference circuit and serial interface logic functions in SOT-23 and MSOP packages. The A/D converter section consists of a conventional successive-approximation converter based around a capacitor DAC. The parts are capable of running on a +2.7 V to +5.5 V power supply. The on-chip temperature sensor allows an accurate measurement of the ambient device temperature to be made. The specified measurement range of the ADT7301 is -40C to +150C. At +150C the ADT7301 is limited to 5% of it's +55C operational life time. The structural integrity of the device will start to deteriorate when operated at voltage and temperature maximum specifications.
CONVERTER DETAILS
Temperature -40C -30C -25C -10C -0.03125C 0C +0.03125C +10C +25C +50C +75C +100C +125C +150C
Digital Output DB13 . . . DB0 11, 11, 11, 11, 11, 00, 00, 00, 00, 00, 00, 00, 00, 01, 1011 1100 1100 1110 1111 0000 0000 0001 0011 0110 1001 1100 1111 0010 0000 0100 1110 1100 1111 0000 0000 0100 0010 0100 0110 1000 1010 1100 0000 0000 0000 0000 1111 0000 0001 0000 0000 0000 0000 0000 0000 0000
The conversion clock for the part is internally generated so no external clock is required except when reading from and writing to the serial port. In normal mode, an internal clock oscillator runs an automatic conversion sequence. During this automatic conversion sequence a conversion is initiated every 1 sec. At this time, the part powers up it's analog circuitry and performs a temperature conversion. This temperature conversion typically takes 800 s, after which time the analog circuitry of the part automatically shuts down. The analog circuitry powers up again when the 1 sec timer times out and the next conversion begins. The result of the most recent temperature conversion is always available in the serial output register as the serial interface circuitry never shuts down. The ADT7301 can be placed in a shutdown mode, via the Control Register, in which case, the on-chip oscillator is shut down and no further conversions are initiated until the ADT7301 is taken out of shutdown mode. The ADT7301 can be taken out of shutdown mode by writing all zeros into the control register. The conversion result from the last conversion prior to shutdown can still be read from the ADT7301 even when it is in shutdown mode. In the normal conversion mode, every time a read or write operation takes place the internal clock oscillator is reset at the end of the read or write operation. This causes the device to start a temperature conversion and the result is typically available 800 s later. Similarly, when the part is taken out of shutdown mode, the internal clock oscillator is started and a conversion is initiated. The conversion result is available typically 800 s later. Reading from the device before a conversion is complete will cause the ADT7301 to stop converting and only start again when serial communitation is finished. This read operation will provide the previous result.
TEMPERATURE VALUE REGISTER
Temperature Conversion Formula: 1. Positive Temperature = ADC Code(d)/32 2. Negative Temperature = (ADC Code*(d) - 16384)/32
*Using all 14 bits of the data byte, includes the sign bit.
Negative Temperature = (ADC Code(d)* - 8192)/32
*DB13 (sign bit) is removed from the ADC Code
01, 0010, 1100, 0000
DIGITAL OUTPUT
00, 1001, 0110, 0000
+75C
00, 0000, 0000, 0001
+0.03125C
-0.03125C
11, 1111, 1111, 1111
TEMPERATURE (C) +150C
-40C
-30C
11, 1100, 0100, 0000
11, 1011, 0000, 0000
The temperature value register is a 14-bit read-only register that stores the temperature reading from the ADC in 13-bit twos complement format plus a sign bit. The MSB (DB13) is the sign bit. The ADC can theoretically measure a temperature span of 255 C. The internal temperaREV. Pr. F -7-
Figure 2. Temperature to Digital Transfer Function
ADT7301
CS
Preliminary Technical Data
t1 t2
1 2 3 4 15 16
t7
SCLK
t3 t4
DOUT LEADING ZEROS DB13 DB12 DB0 DB1 DB0
t8
t5
DIN
t6
POWERDOWN
Figure 3. Serial Interface Timing Diagram
SERIAL INTERFACE
The serial interface on the ADT7301 consists of four wires, CS, SCLK, DIN and DOUT. The interface can be operated in 2-wire mode with CS and DIN tied to Ground, in which case the interface has read-only capability, with data being read from the data register via the DOUT line. It is advisable to utilise CS so as to improve synchronisation between the ADT7301 and the master device.The DIN line is used to write the part into standby mode, if required. The CS line is used to select the device when more than one device is connected to the serial clock and data lines. The part operates in a slave mode and requires an externally applied serial clock to the SCLK input to access data from the data register. The serial interface on the ADT7301 is designed to allow the part to be interfaced to systems that provide a serial clock that is synchronized to the serial data, such as the 80C51, 87C51, 68HC11, 68HC05 and PIC16Cxx microcontrollers as well as DSP processors. A read operation from the ADT7301 accesses data from the Temperature Value Register while a write operation to the part writes data to the Control Register.
Read Operation
edge and the data takes effect at this time i.e., if the part is programmed to go into shutdown, it does so at this point. If the CS is brought high before this sixteenth SCLK edge, the Control Register will not be loaded and the powerdown status of the part will not change. Data is clocked into the ADT7301 on the rising edge of SCLK.
MICROPROCESSOR INTERFACING
The ADT7301's serial interface allows for easy interface to most microcomputers and microprocessors. Figures 4 through 7 show some typical interface circuits. The serial interface on the ADT7301 consists of four wires: CS, DIN, DOUT and SCLK. All interface circuits shown utilize all four interface lines. However, it is possible to operate the interface with three wires. If the application does not require the power-down facility offered by the ADT7301, the DIN line can be tied permanently low. Thus, the interface can be operated from just three wires, SCLK, CS, and DOUT. The serial data transfer to and from the ADT7301 requires a 16-bit read operation. Many 8-bit microcontrollers have 8-bit serial ports and this 16-bit data transfer is handled as two 8-bit transfers. Other microcontrollers and DSP processors transfer 16 bits of data in a serial data operation.
ADT7301 to MC68HC11 Interface
Figure 3 shows the timing diagram for a serial read from the ADT7301. The CS line enables the SCLK input. Thirteen bits of data plus a sign bit are transferred during a read operation. Read operations occur during streams of 16 clock pulses. The first two bits out are Leading Zeros and the next fourteen bits contain the temperature data. If CS remains low and sixteen more SCLK cycles are applied then the ADT7301 loops around and outputs the two leading zeros plus the 14 bits of data that are in the temperature value register. When the CS returns high the DOUT line goes into three-state. Data is clocked out onto the DOUT line on the falling edge of SCLK.
Write Operation
Figure 4 shows an interface between the ADT7301 and the MC68HC11 microcontroller. The MC68HC11 is configured in the master mode with its CPOL bit set to a logic one and its CPHA bit set to a logic one. When the MC68HC11 is configured like this, its SCLK line idles high between data transfers. Data is transferred to and from the ADT7301 in two 8-bit serial data operations. The diagram shows the full (four-wire) interface. PC1 of the MC68HC11 is configured as an output and used to drive the CS input.
ADT7301*
SCLK DOUT DIN CS MC68HC11* SCLK MISO MOSI PC1
Figure 3 also shows the timing diagram for a serial write to the ADT7301. The write operation takes place at the same time as the read operation. Only the third bit in the data stream provides a user-controlled function. This third bit is the power-down bit which, when set to a 1, puts the ADT7301 into shutdown mode. Besides the power-down bit all bits in the input data stream should be zero so as to ensure correct operation of the ADT7301. Data is loaded into the Control Register on the sixteenth rising SCLK -8-
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 4. ADT7301 to MC68HC11 Interface
REV. Pr. F
Preliminary Technical Data
ADT7301 to 8051 Interface
ADT7301
be set up as follows: TFSW = RFSW = 1, Alternate Framing INVRFS = INVTFS = 1, Active Low Framing Signal DTYPE = 00, Right Justify Data SLEN = 1111, 16-Bit Data Words ISCLK = 1, Internal Serial Clock TFSR = RFS = 1, Frame Every Word IRFS = 0, RFS Configured As Input ITFS = 1, TFS Configured As Output The interface requires an inverter between the SCLK line of the ADSP-21xx and the SCLK input of the ADT7301. The ADSP-21xx has the TFS and RFS of the SPORT tied together with TFS set as an output and RFS set as an input. The DSP operates in Alternate Framing Mode and the SPORT Control Register is set up as described above.
ADT7301*
SCLK DOUT DIN CS
An interface circuit between the ADT7301 and the microcontroller is shown in Figure 5. The 8xC51 is configured in its Mode 0 serial interface mode. The serial clock line of the 8xC51 (on P3.1) idles high between data transfers. Data is transferred to and from the ADT7301 in two 8-bit serial data operations. The ADT7301 outputs the MSB of its data stream as the first valid bit while the 8xC51 expects the LSB first. Thus, the data read into the serial buffer needs to be rearranged before the correct data word from the ADT7301 is available in the accumulator. In the example shown, the ADT7301 is connected to the serial port of the 8051. Because the serial interface of the 8xC51 contains only one data line, the DIN line of the ADT7301 is tied low in the interface example given in Figure 5. For applications that require the use of the power-down feature of the ADT7301, the serial interface should be implemented using data port lines on the 8051. This allows a full-duplex serial interface to be implemented. The method involves `bit-banging' a port line to generate a serial clock while using two other port lines to shift data in and out with the fourth port line connecting to CS. Port lines 1.0 through 1.3 (with P1.1 configured as an input) can be used to connect to SCLK, DOUT, DIN and CS, respectively, to implement this scheme.
ADT7301*
SCLK DOUT DIN CS
P3.1 P3.0 P1.2 P1.3 8051*
ADSP-21xx*
SCK DR DT RFS
TFS
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 7. ADT7301 to ADSP-21xx Interface
MOUNTING THE ADT7301
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 5. ADT7301 to 8051 Interface
ADT7301 to PIC16C6x/7x Interface
The ADT7301 can be used for surface or air-temperature sensing applications. If the device is cemented to a surface with thermally conductive adhesive, the die temperature will be within about 0.1C of the surface temperature, thanks to the device's low power consumption. Care should be taken to insulate the back and leads of the device from the air, if the ambient air temperature is different from the surface temperature being measured. The ground pin provides the best thermal path to the die, so the temperature of the die will be close to that of the printed circuit ground track. Care should be taken to ensure that this is in good thermal contact with the surface being measured. As with any IC, the ADT7301 and its associated wiring and circuits must be kept free from moisture to prevent leakage and corrosion, particularly in cold conditions where condensation is more likely to occur. Water-resistant varnishes and conformal coatings can be used for protection. The small size of the ADT7301 package allows it to be mounted inside sealed metal probes, which provide a safe environment for the device.
SUPPLY DECOUPLING
Figure 6 shows an interface circuit between the ADT7301 and the PIC16C6x/7x microcontroller. The PIC16C6x/ 7x Synchronous Serial Port (SSP) is configured as an SPI master with the Clock Polarity bit set to a logic one. In this mode, the serial clock line of the PIC16C6x/7x idles high between data transfers. Data is transferred to and from the ADT7301 in two 8-bit serial data operations. In the example shown, port line RA1 is being used to generate the CS for the ADT7301.
ADT7301*
SCLK DOUT DIN CS
PIC16C6x/7x* SCK SDO SDI RA1
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 6. ADT7301 to PIC16C6x/7x Interface
ADT7301 to ADSP-21xx Interface
The ADT7301 should be decoupled with a 0.1 F ceramic capacitor between VDD and GND. This is particularly important if the ADT7301 is mounted remote from the power supply.
Figure 7 shows an interface between the ADT7301 and the ADSP-21xx DSP processor. To ensure correct operation of the interface the SPORT Control Register should
REV. Pr. F
-9-
ADT7301
OUTLINE DIMENSIONS
Dimensions shown in millimeters.
Preliminary Technical Data
6-Lead Plastic Surface Mount SOT-23 (RJ-6)
2.90 BSC
6 1.60 BSC 1 PIN 1
5 2
4 2.80 BSC 3
0.95 BSC 1.90 BSC 1.30 1.15 0.90 1.45 MAX 0.15 MAX 0.50 0.30 10 0 0.60 0.45 0.30
SEATING PLANE
0.22 0.08
COMPLIANT TO JEDEC STANDARDS MO-178AB
8-Lead Plastic Surface Mount Mini/Micro SOIC (MSOP) (RM-8)
3.00 BSC
8
5
3.00 BSC
1 4
4.90 BSC
PIN 1 0.65 BSC 0.15 0.00 0.38 0.22 COPLANARITY 0.10 1.10 MAX
SEATING PLANE
0.23 0.08
8 0
0.80 0.40
COMPLIANT TO JEDEC STANDARDS MO-187AA
-10-
REV. Pr. F

▲Up To Search▲

Price & Availability of ADT7301

	To Download ADT7301 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .