AS3645A - 2x500mA Photoflash Driver

Description

The AS3645A inductive flash driver drives up to 1000mA (2x500mA) and can be used in single LED flash or double LED flash environments. The high-side current source works with up to 2x500 mA with 2 LEDs in serial configuration, and up to 720 mA with 1 LED. When driving 2 LEDs in series, LEDs draw identical currents and provide output light matching and thermal dissipation. The AS3645A auto detects whether to employ single or dual LED mode, and enables direct one-button flashlight mode. A number of safety features protect against circuit damage and improve test time, including programmable current limiting, auto test (LED open/short detection), overvoltage and undervoltage, overtemperature, and automatic flash timeout timer for thermal LED protection during flash.

These features suit the needs of a camera phone flash, especially in smart phones and feature-phones. For other devices with cameras, including digital still cameras, camcorders and PDAs, the AS3645A flashlight driver is a perfect solution. It’s high efficiency 2 MHz fixed frequency DC-DC boost converter with soft start allows small inductors and enables easy integration into noise sensitive RF systems. The high power LED flash current source can operate in flash, torch, and assist (video) light mode. An additional current source drives an optional indicator LED. Control can be implemented through either the parallel interface mode to allow simple integration, or the I2C interface to allow more sophisticated control of all settings like currents and timings. The interface is selected by a dedicated pin (I2C/EN).

The AS3645A is available in a tiny WL-CSP package (3x4 balls 0.5 mm pitch, 2x1.6 mm) and has an operating temperature range of -30° to +85°C ambient.

주요 특징

• High efficiency 2MHz fixed frequency DCDC
• Stable even in coil current limit
• High Flash LED current up to 2x500mA
• Indicator LED output
• Various safety functions:
  • Flash timeout timer to protect the LEDs
  • Overvoltage and undervoltage protection
  • Overtemperature Protection
  • LED short circuit protection
• Dual Interface selectable by pin
  • parallel interface
  • I2C interface
• Package:
  • WL-CSP12 balls, 2x1.6mm package size, 0.5mm pitch

적용분야

• Mobile phones
• Smart phones
• Digital Still Cameras (DSC)

Block diagram for AS3645A - 2x500mA Photoflash Driver