Texas Instruments Incorporated
Low quiescent current linear regulator with mode selection based on load current and fast transient detection

Abstract:

A system includes an input voltage source, a linear regulator coupled to the input voltage source, and a load coupled to an output of the linear regulator. The linear regulator includes an error amplifier coupled to a control terminal of a switch; and a control circuit coupled to the error amplifier and configured to provide a reference voltage to the error amplifier. The control circuit includes a mode selection circuit with a slow loop configured to sample a load current and with a fast loop configured to detect an output voltage error signal. The mode selection circuit is configured to adjust a mode of the control circuit between a continuous power mode and a duty cycle power save mode based on the sampled load current and the output voltage error signal.