A regulated charge pump circuit having two-way switching means that switches
between
a first feedback pathway that provides a precise and stable voltage output and
a second feedback pathway that provides a regulated voltage output with low current
consumption from the power source. The first feedback pathway maintains a precise
voltage output by regulating a pass device that draws current to the voltage output.
The second feedback pathway regulates the voltage output by controlling the connection
of a clock input to the charge pump. A variable resistor is used to set the regulated
level of the voltage output. A digital-to analog converter is formed by using a
combination logic circuit to convert a digital input signal to a control signal
for the variable resistor.
