10 MHz peak current mode dc-dc converter IC with calibrated current observer

Abstract

Current program mode controllers have not been widely adopted in low-power high frequency dc-dc converters due to the need for an integrated high gain-bandwidth current sensor circuit. This paper presents a peak current program mode controller IC with integrated power-stage that operates at 10 MHz and does not require any high gain-bandwidth analog circuitry in current or voltage loops. A custom bidirectional hybrid delay-line architecture emulates the inductor current based on input and output voltages. A novel calibration circuit is introduced to remove the mismatches between the actual and observed inductor current slopes. The controller consumes 210 μA when the calibration block is off and 430 μA during calibration and the peak efficiency of the converter is 87%.