Power supply controller

摘要

A microcontroller generates a digital signal in response to input data, such as temperature and/or fan speed data. The digital signal is converted to an analog signal that is used to control a variable power supply. The variable power supply outputs a regulated substantially constant output voltage at a voltage level corresponding to the value of the digital signal. The analog signal is produced by a resistor divider and a feedback adjustment circuit that includes a plurality of resistive elements that are selectively coupled in parallel with a portion of the resistor divider in response to the digital signal. The resistive elements coupled in parallel with the portion of the resistor divider adjust the voltage generated at the resistor divider's center node. The voltage on the center node is the analog signal that is used to control the variable power supply.