Tech Shout!

Texas Instruments Inc. (TI) has launched the smallest two-bank, low dropout (LDO) regulator to support light emitting diode (LED) lighting in portable applications, such as mobile phones, navigation systems, MP3 and media players.

The device makes possible quality color backlighting from a tiny 1.2 x 1.2 mm package, enabling end-users to experience blinking and dimming of color keypads and navigation pad lights.

TI’s TPS75105 linear, quad-LDO with matching LED constant current source drives up to four LEDs in two banks with each LED at 25 mA (max). Each bank features independent pulse width modulation (PWM) brightness control that controls the dimming level from “full brightness” to “off”.

Key features of the LED Driver include:

Regulated output current with two percent LED-to-LED matching

28-mV typical dropout voltage extends usable supply range in Li-Ion battery applications

No internal switching signals, eliminating electromagnetic interface (EMI)

Over-current and over-temperature protection

Default LED current eliminates external components

The TPS75105 LED driver, as well as a TPS75103 version that supports 3-mA, are now available in volume production from TI and its worldwide network of distributors. Both LED drivers come in an ultra-small, 9-ball, 0.4 mm ball-pitch wafer chip-scale package (WCSP). Suggested resale price starts at 65 cents in 1,000-unit quantities.