Charge pump circuit with built-in retry

An integrated circuit device comprising:

• an oscillator generating a clock signal;
• a phase generator electrically connected to the oscillator, wherein the phase generator squares a wave of the clock signal output from the oscillator and outputs a square phase clock signal;
• a charge pump electrically connected to the phase generator, wherein the charge pump increases voltage of the square phase clock signal output from the phase generator and outputs a voltage-boosted clock signal, and wherein a precharge operation is performed on the charge pump before increasing the voltage of the square phase clock signal by connecting a boosted output node of the charge pump to a first voltage source;
• and
• a bandgap reference generator electrically connected to the charge pump, wherein the bandgap reference generator outputs a stable voltage reference using the voltage-boosted clock signal output from the charge pump;
• and
• a multiplexor electrically connected to the bandgap reference generator and the charge pump,
• wherein the multiplexor has a first input that receives voltage levels of the voltage-boosted clock signal being output by the charge pump to the bandgap reference generator,
• wherein the multiplexor has a first output that outputs, to the charge pump, either:
• a retry signal, if the voltage levels of the voltage-boosted clock signal being output by the charge pump are below a voltage threshold;
• or a pump signal, if the voltage levels of the voltage-boosted clock signal being output by the charge pump are not below the voltage threshold,
• wherein the pump signal causes the charge pump to output the voltage-boosted clock signal to the bandgap reference generator, and
• wherein the retry signal causes the charge pump to not output the voltage-boosted clock signal to the bandgap reference generator, and to repeat the precharge operation by reconnecting the boosted output node of the charge pump to the first voltage source.

A method comprising:

• generating a clock signal using an oscillator;
• precharging a charge pump that receives the clock signal by connecting a boosted output node of the charge pump to a first voltage source;
• increasing voltage of the clock signal using the charge pump to produce a voltage-boosted clock signal;
• and
• receiving, into a multiplexor, voltage levels of the voltage-boosted clock signal being output by the charge pump;
• outputting from the multiplexor to the charge pump, either:
• a retry signal, if the voltage levels of the voltage-boosted clock signal are below a voltage threshold;
• or
• a pump signal, if the voltage levels of the voltage-boosted clock signal are not below the voltage threshold;
• outputting the voltage-boosted clock signal from the charge pump to the bandgap reference generator in response to the multiplexor outputting the pump signal;
• avoiding outputting the voltage-boosted clock signal from the charge pump to the bandgap reference generator in response to the multiplexor outputting the retry signal;
• and
• repeating the precharging of the charge pump in response to the multiplexor outputting the retry signal by reconnecting the boosted output node of the charge pump to the first voltage source.