AS3645A-ZWLT

Datasheet AS3645 1000/720mA Ultra Small High efficient single/dual LED Flash Driver with Safety Features 1 General Description 2 Key Features High efficiency 2MHz fixed frequency DCDC Boost converter with soft start allows small coils The AS3645 is an inductive high efficient DCDC step up converter with two current sources. The DCDC step up converter operates at a fixed frequency of 2MHz and includes soft startup to allow easy integration into noise sensitive RF systems. The two current sources (one for driving one or two flash LEDs and one for the indicator LED) can operate in flash / torch / assist (=video) light / indicator modes. If a two flash LEDs configuration is used, the LEDs are connected in series. Therefore identical current is guaranteed. - Stable even in coil current limit High Flash LED(s) current (720mA for single flash LED, 1000mA (2x500mA) for dual flash LED) Separate Indicator LED output Flash LED(s) cathode connected to ground: Improved thermal performance (ground = heat sink) Simplified PCB layout The AS3645 includes flash timeout, overvoltage, overtemperature, undervoltage and LED short circuit protection functions. Flash, Torch, Assist and Indicator Mode Protection functions: Automatic Flash Timeout timer to protect the LED(s) Overvoltage and undervoltage Protection Overtemperature Protection LED(s) short circuit protection The AS3645 can be controlled either with parallel interface mode to allow simple integration. Alternatively it 2 can be controlled by I C mode to allow a more sophisticated control of all settings like currents and timings. The interface is selected by a dedicated pin (I2C/EN). Dual Interface selectable by pin (parallel interface 2 mode and I C mode) Available in tiny WL-CSP Packages 3x4 balls 0.5mm pitch, 2x1.6mm package size The AS3645 is available in a space-saving WL-CSP package measuring only 2x1.6mm and operates over the -30ºC to +85ºC temperature range. 3 Applications Flash/Torch for mobile phones, digital cameras and PDA Figure 1. Typical Operating Circuit 

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 $$  $) $ *$ Revision 1.6 1 - 33 AS3645 Datasheet - P i n o u t 4 Pinout Pin Assignment Figure 2. Pin Assignments (Top View)  "  #     
      
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 Pin Description Table 1. Pin Description for AS3645 Pin Number Pin Name Description A1 PGND Power ground - connect to ground (GND) A2 SGND Signal ground - connect to ground (GND) A3 VIN Positive supply voltage input - connect to supply and make a short connection to input capacitor CVIN and to coil LDCDC B1 SW DCDC converter switching node - make a short connection to the coil LDCDC B2 TORCH B3 IND_OUT C1 VOUT C2 STROBE Torch control digital input with pulldown - enables torch function Indicator LED current source output DCDC converter output capacitor - make a short connection to CVOUT 2 I C mode: Digital input with pulldown to control strobe time for flash function parallel interface mode: Open drain output to identify single/dual flash LED 1 Control pin for the operating mode of the AS3645: 2 1. set to high (e.g. VIN) for I C mode 2. set to low (GND) for parallel interface mode with fixed output currents 3. connect a current set resistor to GND (RISET) for parallel interface mode with adjustable output currents C3 I2C/EN D1 LED_OUT Flash LED current source output D2 SDA/EN2 serial data input/output for I C mode (needs external pullup resistor); EN2 input with pulldown for parallel interface mode D3 SCL/EN1 serial clock input in I C mode EN1 input with pulldown in parallel interface mode 2 2 1. Application Note: The pin STROBE is usually connected to the camera processor. www.austriamicrosystems.com Downloaded from DatasheetLib.com - datasheet search engine Revision 1.6 2 - 33 AS3645 Datasheet - A b s o l u t e M a x i m u m R a t i n g s 5 Absolute Maximum Ratings Stresses beyond those listed in Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Table 3, “Electrical Characteristics,” on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Parameter Min Max Units VIN to GND -0.3 +7.0 V TORCH, STROBE, SCL/EN1, SDA/EN2, I2C/ EN, IND_OUT to GND -0.3 VIN + 0.3 V SW, VOUT, LED_OUT to GND -0.3 +18.0 V VOUT or SW to VIN -0.3 SGND, PGND to GND 0.0 Input Pin Current without causing latchup -100 Comments V Note: Diode between VOUT and SW 0.0 V Connect SGND and PGND to GND directly below the pad (short connection recommended) +100 +IIN mA Norm: EIA/JESD78 Continuous power dissipation 1020 mW PT Continuous power dissipation derating factor 14.7 mW/ºC PDERATE ±2000 V Norm: MIL 883 E Method 3015 Continuous Power Dissipation (TA = +70ºC) 1 2 Electrostatic Discharge ESD HBM ESD CDM ±500 V Norm: JEDEC JESD 22-C101C ESD MM ±100 V Norm: JEDEC JESD 22-A115-A level A +150 ºC Internally limited (overtemperature protection) Temperature Ranges and Storage Conditions Junction Temperature Storage Temperature Range -55 +125 ºC Humidity 5 85 % Non condensing +260 ºC according to IPC/JEDEC J-STD-020C Body Temperature during Soldering 1. Depending on actual PCB layout and PCB used; for peak power dissipation during flashing see document 'AS3645 Thermal Measurements' 2. PDERATE derating factor changes the total continuous power dissipation (PT) if the ambient temperature is not 70ºC. Therefore for e.g. TAMB=85ºC calculate PT at 85ºC = PT - PDERATE * (85ºC - 70ºC) www.austriamicrosystems.com Downloaded from DatasheetLib.com - datasheet search engine Revision 1.6 3 - 33 AS3645 Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s 6 Electrical Characteristics VVIN = +2.7V to +5.5V, TAMB = -30ºC to +85ºC, unless otherwise specified. Typical values are at VVIN = +3.6V, TAMB = +25ºC, unless otherwise specified. Table 3. Electrical Characteristics Symbol Parameter Condition Min Typ Max Unit 2.7 3.6 4.8 V 2.7 V 0.5 1.0 µA 0.5 10 µA 25 85 ºC 8.6 V General Operating Conditions VVIN Supply Voltage VVINREDUCE Supply Voltage AS3645 functionally working, but not all parameters fulfilled ISHUTDOWN Shutdown Current parallel interface mode,TORCH=L, SCL/ EN1=L, SDA/EN2=L, VVIN
 
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