Bandgap reference circuit
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJaw-Juinn Horng, Kuo-Feng Yu, Chung-Hui Chen
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Abstract
A bandgap reference circuit includes a first bipolar junction transistor (BJT) in series with a first current generator, the first BJT and the first current generator configured to produce a first proportional to absolute temperature (PTAT) signal. The circuit also includes a second BJT in series with a second current generator, the second BJT and the second current generator configured to produce a second PTAT signal. The bandgap reference circuit maintains a current through at least one of the first BJT or the second BJT within a constant ideality factor region of the at least one of the first BJT or the second BJT.
Claims20
A bandgap reference circuit, comprising:
- a plurality of first bipolar junction transistors (BJTs) arranged in parallel and in series with a first current generator, wherein the plurality of first BJTs and the first current generator are configured to produce a first proportional to absolute temperature (PTAT) signal;
- and
- a plurality of second BJTs arranged in parallel and in series with a second current generator, wherein the plurality of second BJTs and the second current generator are configured to produce a second PTAT signal,
- wherein
- the bandgap reference circuit is configured to maintain a current through at least a first BJT of the plurality of first BJTs or a second BJT of the plurality of second BJTs within a constant ideality factor region of the first BJT of the plurality of first BJTs or of the second BJT of the plurality of second BJTs, and
- the plurality of first BJTs and the plurality of second BJTs are positioned in an array, and at least one row or column of the array comprises two first BJTs of the plurality of first BJTs and two second BJTs of the plurality of second BJTs.
A bandgap reference circuit configured to produce a reference voltage signal from a first proportional to absolute temperature (PTAT) signal and a second PTAT signal, the bandgap reference circuit comprising:
- a first current generator configured to output a first supply current;
- a second current generator configured to output a second supply current;
- a plurality of first bipolar junction transistors (BJTs) in series with the first current generator and configured to produce the first PTAT signal based on the first supply current;
- and
- a plurality of second BJTs in series with the second current generator and configured to produce the second PTAT signal based on the second supply current,
- wherein
- the bandgap reference circuit is configured to maintain emitter currents through a first BJT of the plurality of first BJTs and a second BJT of the plurality of second BJTs within a constant ideality factor region of the corresponding first BJT or second BJT, and
- the plurality of first BJTs and the plurality of second BJTs are positioned in an array, and at least one row or column of the array comprises two first BJTs of the plurality of first BJTs and two second BJTs of the plurality of second BJTs.
A method of generating a reference voltage signal, the method comprising:
- generating a first supply current using a first current generator;
- generating a second supply current using a second current generator;
- using a first bipolar junction transistor (BJT) of a first plurality of BJTs connected in parallel, generating a first proportional to absolute temperature (PTAT) signal from a portion of the first supply current, the portion of the first supply current corresponding to a constant ideality factor region of the first BJT;
- using a second BJT of a second plurality of BJTs connected in parallel, generating a second PTAT signal from a portion of the second supply current, the portion of the second supply current corresponding to a constant ideality factor region of the second BJT;
- and
- outputting the reference voltage signal based on the first PTAT signal and the second PTAT signal,
- wherein the first plurality of BJTs and the second plurality of BJTs are positioned in an array, and at least one row or column of the array comprises two BJTs of the first plurality of BJTs and two BJTs of the second plurality of BJTs.
Dependencies are inferred from the claim text.