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Datasheet
AS3648
2000mA High Current LED Flash Driver
1 General Description
The AS3648 is an inductive high efficient DCDC step up converter with two current sinks. The DCDC step up converter operates at a fixed frequency of 4MHz and includes soft startup to allow easy integration into noise sensitive RF systems. The two current sinks can operate in flash / torch / assist (=video) light modes.
The AS3648 includes flash timeout, overvoltage, overtemperature, undervoltage and LED short circuit protection functions. A TXMASK/TORCH function reduces the flash current in case of parallel operation to the RF power amplifier and avoids a system shutdown. Alternatively this pin can be used to directly operate the torch light directly.
The AS3648 is controlled by an I2C interface and has a hardware automatic shutdown if SCL=0 for 100ms. Therefore no additional enable input is required for shutting down of the device once the system shuts down.
The AS3648 is available in a space-saving WL-CSP package measuring only 2.25x1.5x0.6mm and operates over the -30ºC to +85ºC temperature range.
Figure 1. Typical Operating Circuit
2 Key Features
High efficiency 4MHz fixed frequency DCDC Boost converter with soft start allows small coils - Stable even in coil current limit
LED current adjustable up to 2000mA Two LED operation or single LED operation (com-
bine LED_OUT1 with LED_OUT2)
Automatic current adjustment for low battery voltage
PWM operation for lower output current for reliable light output of the LED; running at 31.25kHz to avoid audible noise
Protection functions: Automatic Flash Timeout timer to protect the LED(s) Overvoltage and undervoltage Protection Overtemperature Protection LED short/open circuit protection
I2C Interface with automatic shutdown
5V constant voltage mode operation
Available in tiny WL-CSP Package, 13 balls 0.5mm pitch 2.25x1.5x0.6mm, package size
3 Applications
Flash/torch/videolight for smartphones, feature-phones, tablets, DSCs, DVCs
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AS3648
Datasheet, Confidential - Pinout
4 Pinout
Pin Assignment
Figure 2. Pin Assignments (Top View)
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Pin Description
Table 1. Pin Description for AS3648
Pin Number A1 A2 A3 B1 B2 C1 C2 C3 D1
D2
E1 E2
E3
Pin Name VOUT1 GND
LED_OUT1 SW1 GND
VOUT2 SW2
LED_OUT2 SCL
VIN
SDA STROBE
TXMASK/ TORCH
Description
DCDC converter output capacitor - make a short connection to CVOUT / VOUT2
Power and analog ground; make a short connection between both balls
Flash LED current sink
DCDC converter switching node - make a short connection .