A voltage regulator for supplying two types of loads on a common chip,
namely a high current load and a low current load. The voltage regulator
employs a feedback loop to supply the low current load with a fine degree
of regulation and a feed forward arrangement to supply the high current
load with a coarse degree of regulation. The feedback loop employs a
bandgap reference source feeding a comparator, with an output driver
transistor drawing current from a common supply and having an output
electrode connected to a voltage divider, allowing a sample of the output
to be fed back to the comparator to maintain the desired output voltage.
The output electrode also feeds a control transistor for the feed forward
arrangement that also draws current from the common supply and supplies
the high current load directly. An example of a single chip circuit
employing the present invention is a charge pump where the high current
load is a series of large capacitors used to multiply charge to produce a
high voltage and the low current load is a plurality of clock circuits
that apply timing pulses to switches for proper phasing of the capacitors
and associated switches to achieve the desired high voltage.