Switching regulator circuit, system, and method for providing input current measurement without a dedicated input current sense element

摘要

A synchronous regulator includes a controller coupled to receive a reference signal and a feedback signal from the regulator and being operable to provide a pulse width modulation (PWM) signal at its output. The regulator includes at least one gate driver coupled to receive the PWM signal and includes a synchronous output switch having a phase node therebetween controlled by the gate driver, and also including regulator input current measurement circuitry. The regulator input current measurement circuitry includes a circuit that provides a signal representative of at least one phase node timing parameter. A sensing circuit is operable to sense inductor or output current provided by the regulator. A calculation circuit is coupled to receive the signal representative of the phase node timing parameters and the inductor or output current and is operable to determine the input current from the phase node timing parameters and the inductor or output current.