Temperature-stable voltage reference circuit
OwnerBrian Cherekinventor
Life of this patent
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Abstract
A voltage reference circuit is disclosed. The circuit comprises a PTAT bias generator circuit and a band gap transistor voltage system coupled to the operational amplifier system. The band gap voltage system includes at least one diode-connected CMOS transistor. The advantage of this configuration is that the diode-connected CMOS device allows for a lower output voltage level than a bipolar device, particularly at colder temperatures. This allows for lower overall operating voltage for the device. The present invention provides for the creation of a temperature-stable reference voltage at a supply voltage and/or operating temperature lower than conventional circuits.
Claims5
A voltage reference circuit comprising:
- a PTAT bias generator circuit;
- and
- a band gap voltage system coupled to the PTAT bias generator circuit;
- wherein the band gap voltage system includes at least one diode-connected CMOS transistor.
A voltage reference circuit comprising:
- a PTAT bias generator circuit;
- a band gap voltage system coupled to the PTAT bias generator circuit;
- wherein the band gap voltage system includes at least one diode-connected CMOS transistor;
- wherein the PTAT bias generator system comprises a first NMOS device;
- a second NMOS device, ratioed in size to the first NMOS device;
- a first resistor, coupled to the second NMOS device;
- two PMOS devices, coupled to the first and second NMOS devices, to form a bias generator loop;
- and a third PMOS device, coupled to the two PMOS devices, and ratioed in size to those the two PMOS devices, to provide a PTAT output current of the bias generator;
- wherein a second resistor is coupled to the PTAT bias generator and the diode-connected CMOS transistor;
- wherein the band gap voltage system includes a third resistor coupled in parallel with the second resistor and the diode-connected CMOS transistor.
Dependencies are inferred from the claim text.