Bandgap reference circuit

Patent metadata

Field	Value
Publication number	US-9612606-B2
Application number	US-201213472063-A
Country	US
Kind code	B2
Filing date	May 15, 2012
Priority date	May 15, 2012
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

A bandgap reference circuit including two sets of bipolar junction transistors (BJTs). A first set of two or more BJTs configured to electrically connect in a parallel arrangement. The first set of BJTs is configured to produce a first proportional to absolute temperature (PTAT) signal. A second set of two or more BJTs configured to electrically connect in a parallel arrangement. The second set of BJTs is configured to produce a second PTAT signal. A circuitry configured to electrically connect to the first set of BJTs and the second set of BJTs. The circuitry is configured to combine the first PTAT signal and the second PTAT signal to produce a reference voltage.

First claim

What is claimed is:

1. A bandgap reference circuit, comprising:
a first set of two or more bipolar junction transistors (BJTs) configured to electrically connect in a parallel arrangement, wherein the first set of BJTs is configured to produce a first proportional to absolute temperature (PTAT) signal; and
a second set of two or more BJTs configured to electrically connect in a parallel arrangement, wherein the second set of BJTs is configured to produce a second PTAT signal,
wherein the first set and the second set of BJTS are collectively arranged in a centroid type pattern, and
a number of BJTs in the second set is defined by Q=(n+E)×(m+E)−n×m, where Q is the number of BJTs in the second set, n is a number of rows of BJTs in the first set, m is a number of columns of BJTs in the first set, and E is an even integer.

2. The bandgap reference circuit of claim 1 , further comprising:
a circuitry configured to electrically connect to the first set of BJTs and the second set of BJTs, wherein the circuitry is configured to combine the first PTAT signal and the second PTAT signal to produce a reference voltage.

3. The bandgap reference circuit of claim 2 , wherein the circuitry is configured to subtract the second PTAT signal from the first PTAT signal.

4. The bandgap reference circuit of claim 1 , wherein the first set of BJTs comprises epitaxial (EPI) BJTs comprising silicon germanium and/or silicon carbide.

5. The bandgap reference circuit of claim 4 , wherein an epitaxial layer of the EPI BJTs are configured to form a hetero-junction.

6. The bandgap reference circuit of claim 1 , wherein the bandgap reference circuit is configured to so each BJT in the first set of BJTs has an ideality factor ranging from about 1.04 to about 1.07.

7. The bandgap reference circuit of claim 1 , wherein the first set of BJTs comprises n-type metal oxide semiconductor BJTs.

8. A bandgap reference circuit configured to provide a reference voltage, the bandgap reference circuit comprising:
a first set of bipolar junction transistors (BJTs) configured to electrically connect in a parallel arrangement, wherein the first set of BJTs comprises a number P of BJTs, the first set of BJTs is configured to produce a first proportional to absolute temperature (PTAT) signal, and P is greater than one; and
a second set of BJTs configured to electrically connect in a parallel arrangement, wherein the second set of BJTs comprises a number Q of BJTs, the second set of BJTS is configured to produce a second PTAT signal, and Q is greater than one, wherein
the first set of BJTs comprises a number P of BJTs equal to a number Q of BJTs in the second set, the first set of BJTs and the second set of BJTs are collectively arranged in a matching pattern, and a first base terminal of the first set of BJTs is coupled to a second base terminal of the second set of BJTs.

9. The band gap reference circuit of claim 8 , further comprising:
a circuitry configured to electrically connect to the first set of BJTs and the second set of BJTs, wherein the circuitry is configured to combine the first PTAT signal and the second PTAT signal to produce a reference voltage.

10. The bandgap reference circuit of claim 9 , wherein the circuitry is configured to subtract the second PTAT signal from the first PTAT signal.

11. The bandgap reference circuit of claim 8 , wherein the first set of BJTs comprises epitaxial (EPI) BJTs.

12. The bandgap reference circuit of claim 8 , wherein an epitaxial layer of the EPI BJTs comprises silicon germanium and/or silicon carbide and is configured to form a hetero-junction.

13. The bandgap reference circuit of claim 8 , wherein the bandgap reference circuit is configured to so each BJT in the first set of BJTs has an ideality factor ranging from about 1.04 to about 1.07.

14. A method of producing a reference voltage, comprising:
producing a first proportional to absolute temperature signal (PTAT) using a first set of two or more bipolar junction transistors (BJTs) doped with silicon germanium to form a hetero-junction configured to electrically connect in a parallel arrangement;
producing a second PTAT using a second set of two or more BJTs configured to electrically connect in a parallel arrangement; and
producing the reference voltage using a circuitry to combine the first PTAT and the second PTAT, wherein the circuitry is configured to electrically connect to the first set of BJTs and the second set of BJTs, and a first base terminal of the first set of two or more BJTs is coupled to a second base terminal of the second set of two or more BJTs.

15. The method of claim 14 , wherein
the producing the first PTAT comprises using the first set of BJTs comprising a number P of BJTs; and
the producing the second PTAT comprises using the second set of BJTs comprising a number Q of BJTs, wherein Q is equal to P, and the first set of BJTs and the second set of BJTs are arranged in a matching pattern.

16. The method of claim 14 , wherein
the producing the first PTAT comprises using the first set of BJTs comprising a number P of BJTs; and
the producing the second PTAT comprises using the second set of BJTs comprising a number Q of BJTs, wherein Q is greater than P, and the first set of BJTs and the second set of BJTs are arranged in a centroid type pattern.

17. The method of claim 16 , wherein the number of BJTs in the second set is defined by Q=(n+E)×(m+E)−n×m, where n is a number of rows of BJTs in the first set, m is a number of columns of BJTs in the first set, and E is an even integer.

18. The method of claim 14 , wherein producing the reference voltage comprises subtracting the second PTAT signal from the first PTAT signal.

19. The method of claim 14 , wherein producing the first PTAT comprises supplying a current to the first set of BJTs such that each BJT of the first set of BJTs has an ideality factor ranging from about 1.04 to about 1.07.

20. The method of claim 14 , wherein the producing the first PTAT using the first set of BJTs comprises using epitaxial (EPI) BJTs.

Assignees

• Horng Jaw-Juinn
• Yu Kuo-Feng
• Chen Chung-Hui
• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Horng Jaw-Juinn
• Yu Kuo-Feng
• Chen Chung-Hui

Classifications

• G05F3/16 Primary

  being semiconductor devices · CPC title

• G05F3/30 Primary

  Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities (G05F3/26 takes precedence) · CPC title