A plurality of constant ON-time buck converters are coupled to a common
load. The output of each buck converter is coupled to a common load via a
series sense resistor. The regulated output voltage across the common
load is compared to a reference voltage to generate a start signal. The
start signal is alternately coupled to the controller on each buck
converter. The ON-time of a master buck converter is terminated when a
ramp signal generated from the regulator input voltage exceeds the
reference voltage. All other slave converters have an ON-time pulse
started by the start signal and stopped by comparing a sense voltage
corresponding to their output current during their ON-time pulse to the
peak current in the master converter during its ON-time. A counting
circuit with an output corresponding to each of the plurality of buck
converters is used to select which buck converter receives the start
signal.