Power management IC having a power supply PWM that is controllable using either an analog or a digital feedback path

摘要

A Power Management Integrated Circuit (PMIC) includes a pulse width modulator and driver circuit (PWMDC), a processor, and high-side and low-side driver circuitry. The PWMDC, along with components external to the PMIC, forms a switching power supply. A small linear regulator powers the PWMDC from power received via a terminal. The power supply supplies power to other on-chip circuitry, including the driver circuitry and processor. The PWMDC starts an on pulse (of a power supply switching cycle) in response to a clock signal. In a first mode, the PWMDC stops the on pulse based on a signal received from a terminal via an analog feedback signal path. In a second mode, the PWMDC stops the on pulse based on a signal received via a digital feedback signal path. In one example, the digital feedback signal path extends from a terminal, through an ADC, processor, and DAC, to an error node.