Low Cost Charge Pump Fires Up LEDs

The CM4072, a low-noise charge pump and linear regulator, powers white LEDs to backlight TFT LCDs in cost-sensitive applications. Residing in a 3 mm x 3 mm, 10-lead TDFN package the device provides a constant 5V output and a continuous output current of 200 mA. To control the brightness, a PWM signal is sent from the baseband processor to the enable pin of the chip. Specifications include a 250-kHz operating frequency, an input-voltage range from 3V to 5V, efficiency up to 83%, a 42-dB PSRR over a 100-Hz to 30-kHz frequency range, operating current of 180 μA, dual enable pins, and over-current and over-temperature protection. Additionally, the device can either drive three white LEDs with a maximum current of 65 mA each or a single, high-brightness flash LED at 200 mA. Price is $0.69 each/1,000. CALIFORNIA MICRO DEVICES CORP., Milpitas, CA. (800) 325-4966.