The present invention provides a versatile system for providing a
current-mode switching controller--in low voltage commercial
semiconductor technologies--that is compatible with applications having
very high input voltage ranges. The system provides an output transistor
and a sense element coupled to the output transistor. A waveform
representative of current charging across the sense element is
recognized. First and second charging elements are provided, and the
second charging element is adapted to charge at a rate twice as fast as
the first charging element. First and second switching elements, coupled
to the first and second charging elements, respectively, are adapted to
activate the first and second charging elements responsive to a rising
edge of the waveform. An output charge element is provided, and a sample
and hold construct is adapted to transfer a charge value--to the output
charge element--that corresponds to an average of the charge values of
the first and second charging elements upon a falling edge of the
waveform.