Driver pumps up white LEDs

Edited by the Electronicstalk editorial team May 13, 2004

The AQ9156 is a 1.5x switched-capacitor (charge pump) regulator, ideal for white LED applications.

The AQ9156 is a 1.5x switched-capacitor (charge pump) regulator, ideal for white LED applications.

The output is a regulated 4.5V, up to 120mA, and capable of driving up to six parallel white LEDs, with a typical operating input voltage range from 3.0 to 6.0V.

It features an efficient, 1.5x charge-pump circuit that uses only two ceramic bucket capacitors and two small filter capacitors for input and output voltage pins, allowing a compact, low-profile system design.

The AQ9156 offers a selectable switching frequency of 8, 32, 262 or 650kHz.

The LED brightness can be adjusted via applying a PWM signal on either the enable pin or second clock pin.

The AQ9156 offers a unique performance advantage over previously available devices, allowing the highest level of efficiency.

A priority design architecture (patent pending) maintains high efficiency (better than 80%), at both below 3.2V input, resulting in longer battery life, and above 5.25V, when an adapter is plugged in, keeping the part cool.

The AQ9156 output voltage is regulated to 4.5V, +/-5% over the line and load ranges, with low output ripple voltage.

Internal overtemperature and overcurrent management provides short-circuit protection.

The AQ9156 is available in a small MLP-10 or MSOP-10 package ($0.98 each, 1000-off).

Evaluation parts are available.