Patent ID: 9501078
Filing Date: 2016-11-22
CPC Classification: G05F

Claim Text:
1. A bandgap voltage reference circuit, comprising: a bias voltage generator circuit for generating a proportional to absolute temperature (PTAT) voltage, the bias voltage generator circuit including a first PTAT current source configured to be coupled to a diode during a first phase of operation and a second PTAT current source configured to be coupled to the diode during a second phase of operation, where the first PTAT current source is configured for providing a higher current level than the second PTAT current source and where the first and second phases occur at different times; a measurement circuit configured to be coupled to the first PTAT current source during the first phase of operation for measuring a base-emitter junction voltage (Vbe) of the diode and to be coupled to the second PTAT current source during the second phase of operation for measuring a shift in Vbe (ΔVbe); a bandgap voltage generator circuit configured to be coupled to the measurement circuit during the second phase of operation for generating a bandgap voltage based on ΔVbe; a first set of switches that are operable during the first phase of operation to couple the measurement circuit to the bias voltage generator circuit; and a second set of switches that during the second phase of operation are operable to couple the measured voltages to the bandgap voltage generator circuit, where the second set of switches are open when the first set of switches are closed and vice-versa, wherein the first and second sets of switches are commanded closed or open based on four clock signals, a first clock signal, a delayed version of the first clock signal, a second clock signal and a delayed version of the second clock signal.