AL3644Typical Applications Circuit 1mH 2.5V to 5V SW IN OUT 10mF
10mF TAL3644C U LED1 D TORCH/ O TEMP R P Flash
STROBE LED W E HWEN LED2 N TX SDA Flash SCL LED GND Pin DescriptionsPin NumberPin NameTypeFunction A1 GND Ground Ground. Input voltage connection. Connect IN to the input supply and bypass to GND with a 10μF or A2 IN Power larger ceramic capacitor. A3 SDA I/O Serial data input/output in the I2C Mode on AL3644. B1 SW Power Drain Connection for Internal NMOS and Synchronous PMOS Switches. Active high hardware flash to enable. Drive STROBE high to turn on Flash pulse. Internal B2 STROBE I/O pulldown resistor of 300kΩ between STROBE and GND. B3 SCL I/O Serial clock input for AL3644. Step-up DC-DC converter output. Connect a 10μF ceramic capacitor between this pin and C1 OUT Power GND. Active high enable pin. High = Standby, Low = Shutdown/Reset. Internal pulldown resistor of C2 HWEN I/O 300kΩ between HWEN and GND. C3 TORCH/TEMP I/O Torch terminal input or threshold detector for NTC temperature sensing and current scale back. D1 LED2 Power High-side current source output for flash LED. Configurable dual polarity power amplifier synchronization input. Internal pulldown resistor of D2 TX I/O 300kΩ between TX and GND. D3 LED1 Power High-side current source output for flash LED.