A multi-phase synchronous buck converter having plural single phase synchronous
buck converter stages, connected together to provide an output current to a load.
A sensing circuit in each converter stage includes a variable gain current sense
amplifier that determines the current through the shunt MOSFET to generate an output
signal representative of the output current provided by that converter stage. The
gains of the current sense amplifiers in each converter stage are preset such that
the output signals from all the amplifiers are substantially equal, thereby balancing
the power loss in all the converter stages by adjustment of the output currents
using varying current sense gains to compensate for variations in the RDS-ON
of the shunt MOSFETS.
