LED driver ICs target small to medium-sized LCDs

Austin, Tex. — Freescale Semiconductor is sampling the first LED backlight product in its power management IC portfolio. The 10-channel MC34844 white LED driver IC with an integrated boost converter is designed for LED backlights in notebook computers, as well as in flat-panel monitors with screen sizes ranging from 10 inches to 27 inches.

The MC34844 IC, housed in a lead-free, 32-pin 5 x 5 x 0.8-mm TQFN package, is reportedly the industry's most compact LED backlight driver IC for notebook and monitor applications. Capable of driving up to 160 LEDs in 10 parallel strings, the highly integrated device provides greater LED control capabilities than any other single-chip solution currently available, according to Freescale.

Using the device's I2C/SMBus interface, developers can program the LED current, PWM frequency and PWM duty cycle for the LEDs. Multiple devices can be synchronized for driving more LEDs. The MC34844 is designed to remove the burden on the controller for PWM generation and to eliminate the need for PWM signals to travel through the printed circuit board, which can cause noise and electromagnetic compatibility performance issues.

In addition, the MC34844's pulse-width modulation (PWM) generator supports LED dimming, a feature that helps improve picture quality and enables a long screen life. The device also is designed to deliver consistent performance over the lifetime of the LEDs by compensating for optical and temperature degradation.

The MC34844 offers an input voltage range of 7 V to 28 V and an output voltage of up to 60 V. The LED driver delivers up to 55 mA LED current per channel. It also features dynamic headroom control to improve device efficiency and a 3.5-A integrated boost. Protection features include user-programmable over-voltage protection, LED open failure detection and OTP/OCP/UVLO lockout.

Pricing: Suggested resale price is $1.44 in quantities of 10,000.
Availability: Sampling for laptop and monitor applications. Broader market availability is planned for fourth quarter 2008.
Product information: MC34844 LED driver ICs

Freescale Semiconductor ,

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