US Patent No. 10,203,715

BANDGAP REFERENCE CIRCUIT FOR PROVIDING A STABLE REFERENCE VOLTAGE AT A LOWER VOLTAGE LEVEL


Patent No. 10,203,715
Issue Date February 12, 2019
Title Bandgap Reference Circuit For Providing A Stable Reference Voltage At A Lower Voltage Level
Inventorship Jian-Sing Liou, Jiangsu (CN)
Assignee ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC., Hsinchu (TW)

Claim of US Patent No. 10,203,715

1. A bandgap reference circuit, comprising:a first amplifier having a first input, a second input, and a first output;
a second amplifier having a third input, a fourth input, and a second output;
a first current source coupled between a power supply node and the first input of the first amplifier;
a second current source coupled between the power supply node and the second input of the first amplifier;
a third current source coupled between the power supply node and the third input of the second amplifier;
a first bipolar transistor having a base, an emitter coupled to the first current source, and a collector coupled to a ground node;
a second bipolar transistor having a base, an emitter coupled to the second current source, and a collector coupled to the ground node;
a first resistor coupled between the third input of the second amplifier and the base of the first bipolar transistor;
a first feedback device coupled between the third current source and the base of the second bipolar transistor, the first feedback device being controlled by the second output of the second amplifier; and
a second resistor coupled between the base of the first bipolar transistor and the base of the second bipolar transistor;
wherein the fourth input of the second amplifier is coupled to one of the first input of the first amplifier and the second input of the first amplifier;
wherein a current flowing through the first resistor is a complimentary to an absolute temperature (CTAT) current; and
wherein a current flowing through the second resistor is a proportional to an absolute temperature (PTAT) current.