Bandgap reference circuit with startup circuit and method of operation

摘要

A band gap reference circuit including a band gap reference generator having an output for providing a reference voltage and a startup circuit for controlling current provided to the band gap reference generator when activated. The startup circuit includes a turnoff circuit having an output to deactivate the startup circuit to not control current to the band gap reference generator based on a voltage of the output of the band gap reference generator. The turnoff circuit includes an inverter having a first transistor of a first conductivity type in series with a second transistor of a second conductivity type opposite the first conductivity type. The startup circuit includes a body bias circuit connected to a body of the first transistor to provide a voltage differential between the body of the first transistor and a source terminal of the first transistor.

主权项

1. A band gap reference circuit comprising:
a band gap reference generator including an output for providing a reference voltage; a startup circuit for controlling current provided to the band gap reference generator when activated, wherein the startup circuit includes:
a turnoff circuit having an output to deactivate the startup circuit to not control current to the band gap reference generator based on a voltage of the output of the band gap reference generator, the turnoff circuit including an inverter coupled to a power supply voltage terminal and having a first transistor of a first conductivity type in series with a second transistor of a second conductivity type opposite the first conductivity type, and a second inverter coupled in series with the inverter, the second inverter coupled to the power supply voltage terminal and having a first transistor of the second conductivity type in series with a second transistor of the first conductivity typea body bias circuit connected to a body of the first transistor of the inverter to provide a voltage differential between the body of the first transistor of the inverter and a source terminal of the first transistor of the inverter which tracks the power supply voltage, wherein a body of the second transistor of the inverter is connected to a source of the second transistor of the inverter; anda second body bias circuit connected to a body of the first transistor of the second inverter to provide a voltage differential between the body and a source terminal of the first transistor of the second inverter which tracks the power supply voltage, wherein a body and a source terminal of the second transistor of the second inventor are connected.