Operational amplifier with different power supply voltages
Assignee02Micro, Inc.
InventorXiaohu TANG
Life of this patent
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Abstract
An operational amplifier with different power supply voltages includes an input stage and an output stage. The input stage includes a current source for providing a bias current, and a differential input circuit for receiving the bias current and differential input voltage signals, and converting the differential input voltage signal to differential input currents. The input stage is supplied by a first power supply voltage. The output stage includes a load circuit coupled to the differential input voltage signal and for receiving the differential input currents, and outputting a single ended output voltage signal. The output stage is supplied by a second power supply voltage. The second power supply voltage is lower than the first power supply voltage.
Claims20
An operational amplifier comprising:
- an input stage comprising:
- a first current source operable for generating a first bias current, and
- a differential input circuit operable for receiving said first bias current and differential input voltage signals, and operable for converting said differential input voltage signals to differential input currents, wherein said input stage is supplied by a first power supply voltage;
- and
- an output stage comprising:
- a load circuit coupled to said differential input circuit and operable for receiving said differential input currents and for outputting a single-ended output voltage signal, wherein said output stage is supplied by a second power supply voltage, and wherein said second power supply voltage is lower than said first power supply voltage.
An operational amplifier comprising:
- a differential input circuit operable for receiving differential input voltage signals and for converting said differential input voltage signals to differential input currents, wherein said differential input circuit comprises a first plurality of transistors;
- a first current source coupled to said differential input circuit, and operable for providing a first bias current for said differential input circuit, wherein said first current source comprises a second plurality of transistors;
- and
- a load circuit coupled to said differential input circuit and operable for receiving said differential input currents and for outputting a single-ended output voltage signal, wherein said load circuit comprises a third plurality of transistors;
- wherein operating voltage thresholds of said third plurality of transistors are lower than operating voltage thresholds of said first and second plurality of transistors.
A battery management system comprising:
- an input circuit for generating differential input voltage signals indicative of a battery cell voltage;
- an operational amplifier coupled to said input circuit and operable for receiving and amplifying said differential input voltage signals, and operable for converting said differential input voltage signals to a single-ended output voltage signal, wherein said operational amplifier comprises an input stage powered by a first power supply voltage and an output stage powered by a second power supply voltage, wherein said second power supply voltage is lower than said first power supply voltage;
- and
- an output circuit coupled to said operational amplifier, and operable for receiving said single-ended output voltage signal and determining said battery cell voltage based on said single-ended output voltage signal.
Dependencies are inferred from the claim text.