Tri-mode charge pump targets high volume cellphone market

Meeting the demanding cost/performance standards of today's mass market consumer cellphones, Advanced Analogic Technologies (AnalogicTech) introduced a high efficiency, low noise, constant frequency charge pump for white LED applications.

The new three-channel, tri-mode charge pump provides the right balance of functionality and silicon overhead to meet the commercial and functional standards that these highly competitive consumer applications require. Integrating a 1X load switch, 1.5X fractional and 2X doubling charge pump, the AAT3142 is optimized for the backlight power requirements of high-volume consumer cellphones with small, efficient color displays.

The tri-mode devices increase efficiency by stepping up voltage only when necessary. Since 80 percent of the discharge cycle of a Li-ion/polymer battery is spent above the 3.5V threshold needed to drive white LEDs, constant use of a charge pump would waste energy. By integrating a 1X load switch, tri-mode devices like the AAT3142 allow the battery voltage to pass through to the output when sufficient voltage is available.

- Henri Arnold

Electronics Express Europe