1 Features

1• Adaptive Charge Pump With 1× and 1.5× Gain

Provides Up to 95% LED Drive Efficiency

• Charge Pump with Soft Start and Overcurrent,

Short-Circuit Protection

• Low Input Ripple and EMI

• Very Small Solution Size, No Inductor or Resistors

Required

• 200-nA Typical Shutdown Current

• Automatic Power Save Mode

• I2C-Compatible Interface

• Independently Programmable Constant Current

Outputs with 8-Bit Current Setting and 8-Bit PWM

Control

• Typical LED Output Saturation Voltage 50 mV and

Current Matching 1%

• Three Program Execution Engines with Flexible

Instruction Set

• Autonomous Operation Without External Control

• Large SRAM Program Memory

• Two General Purpose Digital Outputs

2 Applications

• Fun and Indicator Lights

• LCD Sub-Display Backlighting

• Keypad RGB Backlighting and Phone Cosmetics

• Vibra, Speakers, Waveform Generator

• Blood Glucose Meter

• Handheld POS Terminals

• Electronic Access Control

• Where RGB Indication is Needed

3 Description

The LP5521 is a three-channel LED driver designed

to produce variety of lighting effects for mobile

devices. A high-efficiency charge pump enables LED

driving over full Li-Ion battery voltage range. The

device has a program memory for creating variety of

lighting sequences. When program memory has been

loaded, LP5521 can operate autonomously without

processor control allowing power savings.

The device maintains excellent efficiency over a wide

operating range by automatically selecting proper

charge pump gain based on LED forward voltage

requirements and is able to automatically enter

power-save mode, when LED outputs are not active

and thus lowering current consumption.

Three independent LED channels have accurate

programmable current sources and PWM control.

Each channel has program memory for creating

desired lighting sequences with PWM control.

The LP5521 has a flexible digital interface. Trigger

I/O and a 32-kHz clock input allow synchronization

between multiple devices. Interrupt output can be

used to notify processor, when LED sequence has

ended. The LP5521 has four pin selectable I2Ccompatible

addresses. This allows connecting up to

four parallel devices in one I2C-compatible bus. GPO

and INT pins can be used as a digital control pin for

other devices.

The LP5521 requires only four small, low-cost

ceramic capacitors.

Comprehensive application tools are available,

including command compiler for easy LED sequence

programming.