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PRODUCT DATASHEET
AAT3177
ChargePumpTM
General Description
The AAT3177 is a high output current, high efficiency, low noise, low profile charge pump DC/DC converter. The device is ideal for multi-functional LED photo-flash applications where solution cost, size, and efficiency are critical. The AAT3177 is capable of driving a regulated output current up to 800mA. Output current levels can be easily programmed in 16 steps through AnalogicTech's Simple Serial ControlTM (S2CwireTM) interface controlled by a single microcontroller GPIO line. This allows smooth transitions and flexible adjustment of brightness in flash or other lighting modes. The maximum output current can also be set with an external RSET resistor. The tri-mode (1X/1.5X/2X) operation of the internal charge pump offers excellent power efficiency throughout the output current range for both flash and movie modes. Combined with a low external parts count (two 1F flying capacitors and two small bypass capacitors at VIN and OUT), the AAT3177 is ideally suited for small battery-powered applications. The AAT3177 has a thermal management system to protect the device in the event of a short-circuit condition at the output pin. Built-in soft-start circuitry prevents excessive inrush current during start-up. The shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1A. The AAT3177 is available in a Pb-free, thermallyenhanced 12-pin 3x3mm TDFN package and is specified over the -40C to +85C temperature range.
High Current, High Efficiency Charge Pump with Auto-Timer
Features
* * * * * * * * * * * Up to 800mA Output Current Tri-Mode 1X/1.5X/2X in Current Mode 16 Current Level Steps Set by S2Cwire Flash Auto-Timer (Active for High Current Levels Only) External RSET to Set Maximum Current <1A of Shutdown Small Application Circuit No Inductors Automatic Soft Start 12-Pin TDFN 3x3mm Package -40C to +85C Temperature Range
Applications
* * * * * Camcorders Camera Phones Digital Still Cameras PDAs and Notebook PCs Smart Phones
Typical Application
1F 1F
C1+ 2.7V to 5.5V
CIN 4.7F
C1-
C2+
C2+ OUT
VIN
AAT3177
EN/SET CT GND
COUT 2.2F
Flash LED
EN
FL RSET 187K
0.1F
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PRODUCT DATASHEET
AAT3177
ChargePumpTM
Pin Descriptions
Pin #
1 2 3 4 5 6 7 8 9 10 11 12 EP
High Current, High Efficiency Charge Pump with Auto-Timer
Symbol
VIN C1+ C1GND FL RSET EN/SET CT C2C2+ OUT VIN
Function
Input power supply pin. Connect Pin 1 directly to Pin 12 and then to input supply voltage. Connect a 4.7F or larger ceramic capacitor to ground. Flying capacitor C1 positive terminal. Connect a 1F ceramic capacitor between C1+ and C1-. Flying capacitor C1 negative terminal. Ground connection. Controlled current sink. Connect the flash LED cathode to this pin. Connect resistor here to set maximum output current. Charge pump enable / set input control pin. When in the low state, the AAT3177 is powered down and consumes less than 1A. When connected to logic high level, the AAT3177 charge pump is active. This pin should not be left floating. Flash timeout capacitor. Connect a 0.1F capacitor between this pin and GND for a flash timeout of 1 second. Flying capacitor C2 negative terminal. Flying capacitor C2 positive terminal. Connect a 1F ceramic capacitor between C2+ and C2-. Charge pump output. Connect a 2.2F or larger ceramic capacitor to ground. Connect to flash LED anode to drive the LED. Input power supply pin. Connect Pin 12 directly to Pin 1 and then to input supply voltage. Exposed paddle (bottom). Connect to GND directly beneath package.
Pin Configuration
TDFN33-12 (Top View)
VIN C1+ C1GND FL RSET
1 2 3 4 5 6
12 11 10 9 8 7
VIN OUT C2+ C2CT EN/SET
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
Absolute Maximum Ratings1
TA = 25C, unless otherwise noted. Symbol
VIN VEN VEN(MAX) IOUT TJ TS TLEAD
Description
Input Voltage EN to GND Voltage Maximum EN to Input Voltage Maximum Output Current Operating Temperature Range Storage Temperature Range Maximum Soldering Temperature (at leads, 10 sec)
Value
-0.3 to 6.0 -0.3 to 6.0 VIN + 0.3 1000 -40 to 150 -65 to 150 300
Units
V V V mA C C C
Thermal Information2
Symbol
JA PD
Description
Thermal Resistance Maximum Power Dissipation3
Value
50 2
Units
C/W W
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 2. Mounted on an FR4 board. 3. Derate 20mW/C above 40C ambient temperature.
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
Electrical Characteristics1
CIN = 4.7F, COUT = 2.2F, C1 = C2 = 1.0F; TA = -40C to +85C, unless otherwise noted. Typical values are TA = 25C, VIN = 3.6V. Symbol Description Conditions Min
2.7 1X, No Load Current 3.0 VIN 5.5, 1.5X Mode, No Load Current 3.0 VIN 5.5, 2X Mode, No Load Current EN = 0 VF = 3.6V Programmed for 600mA; RSET = 187k 300 2.0 3.0 800 540 200 0.7 VIN = 2.7V VIN = 5.5V 0.4 1.4 0.3 50 75 500 500 1 75 660
Typ
Max
5.5 4.0 6.0 1.0
Units
V A mA A mA mA s V V V s ns s s s A
Power Supply Input Voltage Range VIN ICC ISHDN(MAX) IOUT(MAX)2 IDX TSS VRSET EN/SET VEN(L) VEN(H) TEN/SET LO TEN/SET HI TEN/SET HI MAX TOFF TLAT Input Current Operating Current VIN Pin Shutdown Current Maximum Output Current Output Current Accuracy Soft-Start Time RSET Pin Voltage Enable Threshold Low Enable Threshold High EN/SET Low Time Minimum EN/SET High Time Maximum EN/SET High Time EN/SET Off Timeout EN/SET Latch Timeout EN/SET Input Leakage
-1
1. The AAT3177 is guaranteed to meet performance specifications from 0C to 70C. Specification over the -40C to +85C operating temperature range is assured by design, characterization, and correlation with statistical process controls. 2. Mounted on an FR4 board.
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PRODUCT DATASHEET
AAT3177
ChargePumpTM
Typical Characteristics
VIN = 3.6V, CIN = 4.7F, COUT = 2.2F, C1 = C2 = 1F, TA = 25C, unless otherwise noted.
High Current, High Efficiency Charge Pump with Auto-Timer
Efficiency vs. Supply Voltage
100 90 80
Turn-On to 1X Mode
(VIN = 4.2V; ILED = 150mA)
Efficiency (%)
70 60 50 40 30 20 10 0 ILED = 150mA
EN (2V/div)
ILED = 300mA
VOUT (2V/div) VSINK (1V/div) IIN (200mA/div)
2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4.0 4.1 4.2
Supply Voltage (V)
Time (200s/div)
Turn-On to 1.5X Mode
(VIN = 3.2V; ILED = 150mA)
Turn-On to 1X Mode
(VIN = 4.2V; ILED = 600mA)
EN (2V/div) VOUT (2V/div) VSINK (1V/div) IIN (200mA/div)
EN (2V/div) VOUT (2V/div) VSINK (1V/div) IIN (500mA/div)
Time (200s/div)
Time (200s/div)
Turn-On to 2X Mode
(VIN = 3.2V; ILED = 600mA)
Turn-Off from 1.5X Mode
(VIN = 3.2V; ILED = 150mA)
EN (2V/div) VOUT (2V/div) VSINK (1V/div) IIN (500mA/div)
EN (2V/div) VF (1V/div)
IIN (200mA/div)
Time (200s/div)
Time (200s/div)
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PRODUCT DATASHEET
AAT3177
ChargePumpTM
Typical Characteristics
VIN = 3.6V, CIN = 4.7F, COUT = 2.2F, C1 = C2 = 1F, TA = 25C, unless otherwise noted.
High Current, High Efficiency Charge Pump with Auto-Timer
Operating Characteristic
(VIN = 3.3V; 1.5X Mode; ILED = 300mA) VIN (100mV/div) VOUT (200mV/div) VSINK (200mV/div)
Operating Characteristic
(VIN = 2.9V; 2X Mode; ILED = 300mA)
VIN (100mV/div) VOUT (200mV/div) VSINK (200mV/div)
Time (2s/div)
Time (2s/div)
LED Current vs. RSET
(Data = 1)
1000 900 800 700 1.8 1.6
Flash Timer Duration
(CT = 0.1F)
-40C 25C
Flash Time (s)
1.4 1.2 1.0 0.8 0.6
ILED (mA)
600 500 400 300 200 100 0 100 200 300 400 500 600 700 800 900 1000
85C
2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
0.4
RSET (k)
Supply Voltage (V)
EN/SET Latch Timeout vs. Supply Voltage
EN/SET Latch Timeout (s)
350 300 250 200 150 100 50 0 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 350
EN/SET Off Timeout vs. Supply Voltage
EN/SET Off Timeout (s)
300 250 200 150 100 50 0
25C -40C 85C
25C -40C 85C
2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
Supply Voltage (V)
Supply Voltage (V)
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PRODUCT DATASHEET
AAT3177
ChargePumpTM
Typical Characteristics
VIN = 3.6V, CIN = 4.7F, COUT = 2.2F, C1 = C2 = 1F, TA = 25C, unless otherwise noted.
High Current, High Efficiency Charge Pump with Auto-Timer
EN/SET High Threshold Voltage vs. Supply Voltage and Temperature
1.0 0.9 0.8 0.7 0.6 0.5 0.4 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 1.0
EN/SET Low Threshold Voltage vs. Supply Voltage and Temperature
0.9 0.8 0.7 0.6 0.5 0.4 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5
-40C VEN(L) (V)
-40C
VEN(H) (V)
25C
85C
25C
85C
Supply Voltage (V)
Supply Voltage (V)
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
Functional Block Diagram
C1+ C1C2+ C2-
VIN
Charge Pump Section 1 Charge Pump Section 2
1MHz Oscillator Soft-Start Control
OUT
FL
EN/SET
System Control; S2Cwire; Timing
RSET
CT
GND
Functional Description
The AAT3177 is a high efficiency, low noise, dual stage tri-mode 1X/1.5X/2X charge pump device intended for photo-flash LED applications. The device requires only four external components: two ceramic capacitors for the charge pump flying capacitors, one ceramic capacitor for CIN, and one ceramic capacitor for COUT. The charge pump is designed to deliver regulated load currents up to 800mA. The dual stage charge pump section contains soft-start circuitry to prohibit excessive inrush current during start-up. System efficiency is maximized with a tri-mode, dual stage charge pump topology. The internal clock oscillator at 1MHz allows the use of small external components. The tri-mode charge pump operation further optimizes power conversion efficiency. Depending upon the variance of load current (at different modes), input voltage, and nominal LED forward voltage, the charge pump will operate in a 1X, 1.5X, or 2X mode to generate the output voltage required to power the load for a given controlled
constant current. This results in significant power savings over voltage doubling architectures, especially when the LEDs are also operated at lower current levels in movie, viewing, or flashlight modes.
S2Cwire Serial Interface
The AAT3177 utilizes Analogic Tech's single wire S2Cwire interface to enable/disable the charge pump and adjust the output current at 16 current levels. Each code defines the output current to be a percentage of the maximum current set by the resistor at the RSET pin (see Table 1). The S2Cwire interface records rising edges of the EN/SET pin and decodes them into 16 individual current level settings with Code 1 reserved for maximum current. Once EN/SET has been held in the logic high state for time TLAT (500s), the programmed current is seen at the current source outputs and the internal data register is reset to 0. For subsequent current level programming, the number of rising edges corresponding to the desired code must be applied on the EN/SET pin.
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
THI TLO T LAT TOFF
EN/SET
1 2 n-1 n 16
Data Reg
0
n-1
0
Figure 1: S2Cwire Serial Interface Timing.
Data
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Output Current (% of IMAX)
100.01 89.11 79.41 70.81 63.1 56.2 50.1 44.7 39.8 35.5 31.6 28.2 25.1 22.4 20.0 0.0
Flash Auto-Timer Enabled
Yes Yes Yes Yes No No No No No No No No No No No No
Application Information
Selecting a Timer Capacitor for CT
The CT pin must be configured according to the desired flash function1. There are two options: connect a small valued capacitor or connect the pin to GND. Configure the timer feature for the AAT3177 by connecting a small valued capacitor between the CT pin and GND. The value of the capacitor will determine the timeout duration according to the following formula:
T = CT * 10
s F
Table 1: Current Level Settings. When EN/SET is held low for an amount of time longer than TOFF (500s), the AAT3177 enters into shutdown mode and draws less than 1A from VIN. Data and address registers are reset to 0 during shutdown. The flash timer is active for DATA values 1 through 41. For lower current settings (DATA 5 through 16) the flash timer is turned off to allow extended LED on time for movie mode applications. When changing from high current (DATA = 1-4) to lower current (DATA = 5-16) the timer will be ignored. When changing from low current to high current the timer will be reset and restarted. The charge pump will be reset during current level changes to allow the system to operate in the most efficient mode.
As an example, the result of connecting a 0.1F capacitor between the CT pin and GND will be a 1 second timeout duration. Operationally, when the AAT3177 is enabled, it will automatically disable itself after 1 second. When using the auto-timer feature, select a CT capacitor value according to the formula above. To disable the auto-timer feature, connect the CT pin to ground. The result will be a small bias current of approximately 3A. A large valued pull-down resistor should not be used for connecting the CT pin to GND. The CT pin can be connected directly to GND. If a pull-down resistor is preferred, it should be of low value (i.e., less than 10K). The primary considerations for selecting the capacitor type are leakage current and tolerance of the capacitor value. The auto-timer duration is determined by charging and discharging the timing capacitor with a small charging/discharging current of approximately 3A. Avoid leaky capacitor types as they will distort the timeout duration. Select the capacitor value's tolerance according to the desired time-out tolerance.
1. Flash Timer is enabled only for the four highest current level settings (DATA = 1, 2, 3, and 4).
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
Flash/Torch Control Using the RSET Pin
An alternative method can be used for flash/torch control that eliminates the need to use the S2Cwire singlewire interface. By using any typical digital I/O port, an additional enable can be created (see Figure 3). The I/O port output configuration can be an open-drain NMOS or open-drain PMOS, but not a push-pull type. The control will always act as an active-low flash enable or, equivalently, an active-high torch enable (see Table 2). EN
0 0 1 1
Real-Time Control of the CT Pin
To achieve flash and torch mode control, the auto-timer can be enabled or disabled in real-time. This can be done by connecting a microcontroller or microprocessor GPIO port to the CT pin. To set up flash mode in real-time, enable the auto-timer by tri-stating the GPIO port. Do not drive the port high. It can only be set to high-impedance so that the CT capacitor can be charged and discharged by the AAT3177. To set up torch mode in real-time, disable the autotimer by driving the GPIO port low so that the CT pin will be pulled to GND through the GPIO port.
ENFL
0 1 0 1
Mode
Off Off Flash Torch
AAT3177
EN/SET
Table 2: Flash/Torch Control Modes. According to I/O port type, the following equations can be used to calculate appropriate resistor values. For an open-drain NMOS I/O port output configuration, the line is pulled low to GND or left floating, according to state. To calculate the appropriate R1 and R2 resistor values, first calculate the R1 resistor value needed for the desired torch level LED current:
Tri-state = TMR ON Low = TMR OFF 0.1F = 1 sec
CT
Figure 2: Enable or Disable the Auto-Timer in Real-Time for Flash/Torch Control.
R1 =
600mA * 187k ILED (torch)
C1 1F
C2 1F
C1+ 2.7V to 5.5V
CIN 4.7F
C1-
C2+
C2+ VOUT
AAT3177
EN/SET CT GND
COUT 2.2F
Flash LED
EN ENCT
CT
F1 R2 RSET R1 ENF
Figure 3: Flash/Torch Control Using the RSET Pin.
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
When the input voltage is sufficiently greater than the LED forward voltage, the device optimizes efficiency by operating in 1X mode. In 1X mode, the device is working as a bypass switch and passing the input supply directly to the output. The power conversion efficiency can be approximated by: Next, choose R2 based on the desired flash level LED current:
R2 =
R1 * 600mA * 187k R1 * ILED (flash) - 600mA * 187k
The current and resistance values used in the equations come from the conditions placed on the IDX parameter of the Electrical Characteristics table. For examples of standard 1% values where the LED flash current level is targeted for 700mA, see Table 3. ILED Torch (mA)
122 153 173 200
=
VF * ILED VF VIN * IIN VIN
R1 (k)
920 732 649 562
R2 (k)
193 205 210 223
ILED Flash (mA)
703 701 707 703
Due to the very low 1X mode quiescent current, the input current nearly equals the current delivered to the LED. Further, the low-impedance bypass switch introduces negligible voltage drop from input to output. The AAT3177 further maintains optimized performance and efficiency by detecting when the input voltage is not sufficient to sustain LED current. The device automatically switches to 1.5X mode when the input voltage drops too low in relation to the LED forward voltage. In 1.5X mode, the output voltage can be boosted to 3/2 the input voltage. The 3/2 conversion ratio introduces a corresponding 1/2 increase in input current. For ideal conversion, the 1.5X mode efficiency is given by:
Table 3: Open-Drain I/O Example Resistor Values. If the I/O port must be configured as an open-drain PMOS type output, the appropriate equations can be generated from these same concepts. As done in the previous example, the necessary values can then be calculated. As a reference, the equations applicable to the PMOS case are:
=
VF VF * ILED = VIN * 1.5IIN 1.5 * VIN
R1 =
600mA * 187k ILED (flash)
VIO -1 0.7 R2 = ILED (torch) 1 R1 600mA * 187k
The value to use for VIO must come from the I/O supply voltage used in the system. 0.7V is the typical value of the VRSET parameter found in the Electrical Characteristics section of this datasheet.
Similarly, when the input falls further, such that 1.5X mode can no longer sustain LED current, the device will automatically switch to 2X mode. In 2X mode, the output voltage can be boosted to twice the input voltage. The doubling conversion ratio introduces a corresponding doubling of the input current. For ideal conversion, the 2X mode efficiency is given by:
=
VF VF * ILED = VIN * 2IIN 2 * VIN
Device Power Efficiency
The AAT3177 power conversion efficiency depends on the charge pump mode. By definition, device efficiency is expressed as the output power delivered to the LED divided by the total input power consumed.
LED Selection
The AAT3177 is designed to drive high-intensity white LEDs. It is particularly suitable for LEDs with an operating forward voltage in the range of 4.2V to 1.5V. The charge pump device can also drive other loads that have similar characteristics to white LEDs. For various load types, the AAT3177 provides a high-current, programmable ideal constant current source.
=
POUT PIN
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PRODUCT DATASHEET
AAT3177
ChargePumpTM
Capacitor Selection
Careful selection of the four external capacitors CIN, C1, C2, and COUT is important because they will affect turn-on time, output ripple, and transient performance. Optimum performance will be obtained when low equivalent series resistance (ESR) ceramic capacitors are used. In general, low ESR may be defined as less than 100m. A value of 1F for the flying capacitors is a good starting point when choosing capacitors. If the LED current sinks are only programmed for light current levels, then the capacitor size may be decreased. Ceramic composition capacitors are highly recommended over all other types of capacitors for use with the AAT3177. Ceramic capacitors offer many advantages over their tantalum and aluminum electrolytic counterparts. A ceramic capacitor typically has very low ESR, is lowest cost, has a smaller PCB footprint, and is nonpolarized. Low ESR ceramic capacitors help maximize charge pump transient response. Since ceramic capacitors are non-polarized, they are not prone to incorrect connection damage.
High Current, High Efficiency Charge Pump with Auto-Timer
These larger devices can improve circuit transient response when compared to an equal value capacitor in a smaller package size.
Thermal Protection
The AAT3177 has a thermal protection circuit that will shut down the charge pump if the die temperature rises above the thermal limit, as is the case during a shortcircuit of the OUT pin.
PCB Layout
To achieve adequate electrical and thermal performance, careful attention must be given to the PCB layout. In the worst-case operating condition, the chip must dissipate considerable power at full load. Adequate heat-sinking must be achieved to ensure intended operation. Figure 4 illustrates an example of an adequate PCB layout. The bottom of the package features an exposed metal paddle. The exposed paddle acts, thermally, to transfer heat from the chip and, electrically, as a ground connection. The junction-to-ambient thermal resistance (JA) for the package can be significantly reduced by following a couple of important PCB design guidelines. The PCB area directly underneath the package should be plated so that the exposed paddle can be mated to the top layer PCB copper during the re-flow process. This area should also be connected to the top layer ground pour when available. Further, multiple copper plated thru-holes should be used to electrically and thermally connect the top surface paddle area to additional ground plane(s) and/or the bottom layer ground pour. The chip ground is internally connected to both the paddle and the GND pin. The GND pin conducts large currents and it is important to minimize any differences in potential that can result between the GND pin and exposed paddle. It is good practice to connect the GND pin to the exposed paddle area using a trace as shown in Figure 4. The flying capacitors C1 and C2 should be connected close to the chip. Trace length should be kept short to minimize path resistance and potential coupling. The input and output capacitors should also be placed as close to the chip as possible.
Equivalent Series Resistance
ESR is an important characteristic to consider when selecting a capacitor. ESR is a resistance internal to a capacitor that is caused by the leads, internal connections, size or area, material composition, and ambient temperature. Capacitor ESR is typically measured in milliohms for ceramic capacitors and can range to more than several ohms for tantalum or aluminum electrolytic capacitors.
Ceramic Capacitor Materials
Ceramic capacitors less than 0.1F are typically made from NPO or C0G materials. NPO and C0G materials generally have tight tolerance and are very stable over temperature. Larger capacitor values are usually composed of X7R, X5R, Z5U, or Y5V dielectric materials. Large ceramic capacitors are often available in lower-cost dielectrics, but capacitors greater than 4.7F are not typically required for AAT3177 applications. Capacitor area is another contributor to ESR. Capacitors that are physically large will have a lower ESR when compared to an equivalent material smaller capacitor.
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
Evaluation Board User Interface
The user interface for the AAT3177 evaluation board is provided by 3 buttons and a couple of connection terminals. The board is operated by supplying external power and pressing individual buttons or button combinations. The table below indicates the function of each button or button combination. To power-on the evaluation board, connect a power supply or battery to the DC- and DC+ terminals. Make the board's supply connection by positioning the J1 jumper to the ON position. A red LED indicates that power is applied. The evaluation board is made flexible so that the user can disconnect the enable line from the microcontroller and apply an external enable signal. By removing the jumper from J2, an external enable signal can be applied to the board. Apply the external enable signal to the ON pin of the J2 terminal. Figure 4: Example PCB Layout. When applying an external enable signal, consideration must be given to the voltage level. The externally applied voltage cannot exceed the supply voltage that is applied to the VIN pins of the device (i.e., DC+).
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PRODUCT DATASHEET
AAT3177
ChargePumpTM
Button(s) Pushed1, 2
DATA MOVIE+DATA FLASH MOVIE DATA+FLASH+MOVIE
High Current, High Efficiency Charge Pump with Auto-Timer
Description
Increments through the 16 data settings. Hold down to auto-cycle. Decrement the data setting. Hold down to auto-cycle. Generate a flash pulse. Current level determined by the DATA setting (defaults to DATA 1). Trim-pot VR4 sets timeout duration. Flash will not time out for low current settings (DATA=5-16). Toggle on/off movie mode illumination. Current level determined by the DATA setting. Leave on to see effects of changing DATA. Movie mode will time out for high current settings (DATA=1-4). Reset, shutdown.
Table 5: Evaluation Board User Interface.
Figure 5: AAT3177 Evaluation Board Top Side Layout.
Figure 6: AAT3177 Evaluation Board Bottom Side Layout.
1. The `+' sign indicates that these buttons are all pressed and released together. 2. Flash timeout duration is adjustable from 10ms to 2 seconds. Rotate trim pot VR4 clockwise to reduce the duration. When the timeout duration determined by the value of CT is set to be less than the VR4 setting, it will supersede.
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PRODUCT DATASHEET
AAT3177
ChargePumpTM High Current, High Efficiency Charge Pump with Auto-Timer
Evaluation Board Schematic
DCDC+ J1 VIN
C4 4.7F C1 1F
1 2 3 4 5 6
U1 AAT3177 VIN VIN C1+ VOUT C1C2+ GND C2F1 CT RSET EN/SET
12 11 10 9 8 7
C2 1F
C3 2.2F
OSRAM OPTO Ceramos Flash LED LW C9SP
D1
R8 187K
R8 = 187K for 600mA
C5 0.1F
R6 J2 100K
R7 220 R3 1K DATA FLASH MOVIE SW3 SW2 SW1 R2 1K R1 1K U2
1 VDD 2 GP5 3 GP4 4
DC+
GP3
VSS GP0 GP1 GP2
8 7 6 5
VR4 POT10K
C6 1uF
R5 330 LED7 RED
PIC12F675
Figure 7: AAT3177 Evaluation Board Schematic.
Evaluation Board Component Listing
Component
U1 U2 D1 R1-R3 C1-C2 C3 C4 C5 C6 R5 R6 R7 R8 VR4 LED7 J1-J2 SW1-SW3
Part Number
AAT3177 PIC12F675 LW C9SP Chip Resistor GRM18x GRM18x GRM18x GRM18x GRM31x Chip Resistor Chip Resistor Chip Resistor Chip Resistor EVN-5ESX50B14 CMD15-21SRC/TR8 PRPN401PAEN PTS645TL50
Description
Tri-Mode High Eff. CP for White LED Flash; DFN33-12 Package 8-bit CMOS, FLASH-based C; 8-pin PDIP Package Ceramos TopLooker, High Brightness Flash LED 1K, 5%, 1/4W; 1206 1.0F, 10V, X5R, 0603, Ceramic 2.2F, 10V, X5R, 0603, Ceramic 4.7F, 6.3V, X5R, 0603, Ceramic 0.1F, 16V, X7R, 0603, Ceramic 1.0F, 10V, X5R, 1206, Ceramic 330, 5%, 1/4W; 1206 100K, 5%, 1/4W; 1206 220, 5%, 1/4W; 1206 187K, 1%, 1/10W; 0603 10K POT; 3mm Squared SMD Red LED; 1206 Conn. Header, 2mm Switch Tact, SPST, 5mm
Manufacturer
AnalogicTech Microchip OSRAM OPTO Vishay Murata Murata Murata Murata Murata Vishay Vishay Vishay Vishay Panasonic-ECG Chicago Miniature Lamp Sullins Electronics ITT Industries
3177.2008.06.1.0
www.analogictech.com
15
PRODUCT DATASHEET
AAT3177
ChargePumpTM
Ordering Information
Package
TDFN33-12
High Current, High Efficiency Charge Pump with Auto-Timer
Marking1
4AXYY
Part Number (Tape and Reel)2
AAT3177IWP-T1
All AnalogicTech products are offered in Pb-free packaging. The term "Pb-free" means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more information, please visit our website at http://www.analogictech.com/about/quality.aspx.
Package Information3
TDFN33-12
Index Area Detail "A" 0.43 0.05
3.00 0.05
2.40 0.05
0.1 REF C0.3 0.45 0.05
Pin 1 Indicator (optional)
3.00 0.05
1.70 0.05
Top View
Bottom View Detail "A"
0.75 0.05
0.05 0.05
Side View
All dimensions in millimeters.
1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. 3. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection.
Advanced Analogic Technologies, Inc. 3230 Scott Boulevard, Santa Clara, CA 95054 Phone (408) 737-4600 Fax (408) 737-4611
(c) Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Except as provided in AnalogicTech's terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders.
16
www.analogictech.com
0.23 0.05
0.23 0.05
3177.2008.06.1.0

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