DESCRIPTION

The ZXLD1101 is a PFM inductive boost converter designed for driving 2, 3 or 4 series connected white LEDs from a Li-Ion cell and up to 8 LEDs from a 5V supply. The device operates from an input supply of between 2.5V and 5.5V and provides an adjustable output current of up to 50mA.

The ZXLD1101 includes the output switch and peak current sense resistor, and can operate with a maximum output voltage of 28V.

Quiescent current is typically 60μA and a shutdown function is provided to reduce this current to less than 500nA in the off state.

Output current can be adjusted by applying a PWM control signal to the Enable pin. Depending upon the control frequency, this will provide either a continuous or a chopped output current. The PWM filter components are contained within the chip.

The device is assembled in the TSOT23-5 pin package with 1mm maximum height profile.

ADVANCED FEATURES

• True Analog Dimming via PWM

FEATURES

• 1mm height profile TSOT23-5 pin package

• Internal PWM filter for flicker free output

• High efficiency (80% typ)

• Wide input voltage range: 2.5V to 5.5V

• Up to 50mA output current

• Low quiescent current: (60μA typ)

• 500nA maximum shutdown current

• Up to 1MHz switching frequency

• Low external component count

• Inherently matched LED currents

APPLICATIONS

• Mobile phones

• Digital cameras

• PDAs

• LCD modules

• Portable internet appliances

• Palmtop computers