1.5 A LED Flash Driver with IC-Compatible Interface

The ADP1650 is a very compact, highly efficient, single white LED flash driver for high resolution camera phones that improves picture and video quality in low light environments. The device integrates a programmable 1.5 MHz or 3 MHz synchronous inductive boost converter, an I2C-compatible interface, and a 1500 mA current source. The high switching frequency enables the use of a tiny, 1 mm high, low cost, 1 μH power inductor, and the current source permits LED cathode grounding for thermally enhanced, low EMI, and compact layouts.

The LED driver maximizes efficiency over the entire battery voltage range to maximize the input-power-to-LED-power conversion and to minimize battery current draw during flash events. A programmable dc battery current limit safely maximizes LED current for all LED VF and battery voltage conditions.

Two independent TxMASK inputs permit the flash LED current and battery current to reduce quickly during a power amplifier current burst. The I2C-compatible interface enables the programmability of timers, currents, and status bit readback for operation monitoring and safety control.

The ADP1650 comes in a compact 12-ball, 0.5 mm pitch WLCSP package and operates within specification over the full −40°C to +125°C junction temperature range.

APPLICATIONS

* Camera-enabled cellular phones and smart phones

* Digital still cameras, camcorders, and PDAs

* Ultracompact solution

Small, 2 mm × 1.5 mm, 12-ball WLCSP package

Smallest footprint, 1 mm height, 1 μH power inductor

LED current source for local LED grounding

Simplified routing to/from LED Improved LED thermals

Synchronous 3 MHz PWM boost converter, no external diode

* High Efficiency: 90% Peak

Reduces high levels of input battery current during flash

Limits battery current drain in torch mode