US 12,189,411 B2
Bandgap reference with input amplifier for noise reduction
Sandeep Shylaja Krishnan, Kozhikode (IN); Tallam Vishwanath, Bengaluru (IN); and Akshay Yashwant Jadhav, Pune (IN)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed on Jan. 26, 2024, as Appl. No. 18/423,948.
Application 18/423,948 is a division of application No. 17/314,637, filed on May 7, 2021, granted, now 11,914,411.
Claims priority of application No. 20204109448 (IN), filed on May 7, 2020.
Prior Publication US 2024/0168510 A1, May 23, 2024
Int. Cl. G05F 3/30 (2006.01); G05F 3/22 (2006.01); G05F 3/26 (2006.01); H03F 3/45 (2006.01)
CPC G05F 3/265 (2013.01) [G05F 3/222 (2013.01); G05F 3/225 (2013.01); G05F 3/30 (2013.01); H03F 3/45179 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A bandgap reference circuit, comprising:
a first bipolar junction transistor (BJT) having a first emitter, a first base, and a first collector, the first base shorted to the first collector;
a second BJT coupled to the first BJT via a first resistor, the second BJT having a second emitter, a second base, and a second collector;
a third BJT coupled to the first BJT, the third BJT having a third emitter, a third base, and a third collector, the third base coupled to the first base, and the third collector coupled to the first collector;
a fourth BJT coupled to the third BJT, the fourth BJT having a fourth emitter, a fourth base, and a fourth collector, the fourth base shorted to the fourth collector, and the fourth base coupled to the second base;
a second resistor coupled to the fourth emitter;
a third resistor coupled to the first and third collectors; and
an operational amplifier having a first input coupled to the first resistor and the second collector, a second input coupled to the third emitter and the fourth collector, and an output coupled to the second emitter and to the second resistor.