High-efficiency white LED drivers from Arques

Sept. 14, 2004
Arques Technology has introduced the newest additions to its expanding line of white LED drivers, the AQ9156B and AQ9153.
These dual-mode 1X - 1.5X switched-capacitor (charge pump) regulators are ideal for white LED backlighting and photo flash applications.
Arques 9153 and 9156B The output is a regulated 4.5V, with up to 120 mA continuous output current, or 200 mA pulse current. They are capable of driving up to six parallel white LEDs, over the typical Li-Ion input voltage range of 3.0V to 6.0V.

The drivers feature an efficient, 1.5X charge-pump circuit that uses only two ceramic bucket capacitors and two small filter capacitors for VIN and VOUT, allowing a compact, low profile system design.

LED brightness can be adjusted by applying a PWM signal to the ENA pin. This pin can also be used for the timed photo flash. The AQ9156B offers a selectable switching frequency of 262 kHz or 650 kHz, while the AQ9153 features a fixed 650 kHz frequency.

The AQ9156B and AQ9153 are claimed to offer unique performance advantages over previously available devices, allowing the highest level of efficiency. A proprietary design architecture (patent pending) maintains high efficiency (over 80%), at both below 3.2 VIN, resulting in longer battery life, and above 5.25V, when an adapter is plugged in, keeping the part cool.

The output voltage is regulated to 4.5V, +/-5% over the line and load ranges, with low output ripple voltage. Internal over-temperature and over-current management provides short circuit protection.

The AQ9156B is available in a small MLP-10 or MSOP-10 package ($0.99 ea/1000), also available in optional Green (halogen-free, Pb-free) packaging. The AQ9153 is available in a very small MSOP-8 package ($0.79 ea/1000).