Step-down Power Converter
Semtech Corp. announces the SC250 and SC251, members of a DC/DC step-down (buck) power converter family designed to improve battery life by providing adaptive DC power control in CDMA and WCDMA handsets. CDMA and WCDMA handsets experience wide swings in power consumption based upon their distance from a base station. The SC250 and SC251 are designed to work with the phone’s base-band processor to enhance the phone’s efficiency by adaptively controlling the DC power supply to the power amplifier (PA). The SC250 performs a buck conversion to generate an output voltage that is linearly proportional to an analog input control voltage from the base-band processor. The buck conversion process reduces battery current when the PA outputs low power, greatly increasing talk time compared to directly connecting the PA to the battery.