Date: 03/11/2008

4-Channel LED drivers targets entry-level cell phones

AAT3104and AAT3195, two new 4-channel, charge pump-based LED drivers from Advanced Analogic Tech is suitable for reduced feature set cell phones and portable systems with larger displays. Available in compact 2 x 2.1mm packages, the devices offer designers 16-step, 32-step or PWM current control. The AAT3104 provides common current sinks for command anode configurations, while the AAT3195 supports common sources for common cathode configurations.
The AAT3104 is a current-source LED driver capable of driving up to four LEDs at up to 30mA each. The charge pump-based device automatically switches between a 1x and 2x mode to maximize efficiency and optimize LED current accuracy and matching. LED output current matching is +/- 10%. LED output current matching is +/- 3%.


The device operates at a 1 MHz switching frequency and comes in two versions that offer either 16-step (AAT3104-1) or 32-step (AAT3104-2) control of LED brightness via

For LEDs using common cathode configurations, the AAT3195 offers a charge pump-based current-source LED driver for similar 4-channel applications. Like the AAT3104, the AAT3195 drives up to 4 LEDs at up to 30mA each. The AAT3195 also automatically switches between 1x and 2x mode. LED output current accuracy is +/- 10%, while LED output current matching is +/- 3%.


The AAT3195 operates at a 1 MHz switching frequency and comes in three versions with different interfaces. The AAT3195-1 delivers 30mA current across 32-steps using the S2Cwire interface. The AAT3195-2 supports 20mA current across 32 steps also using the S2Cwire interface. And the AAT3195-3 features a PWM interface.


Both drivers feature automatic soft-start, a low-current shutdown mode to conserve power, and integrated thermal protection.


Price: Each $0.87 in 1K quantities.