US 11,984,859 B2
Chopper amplifying circuit employing negative impedance compensation technique
Zhiming Liang, Guangdong (CN); Bin Li, Guangdong (CN); and Zhaohui Wu, Guangdong (CN)
Assigned to SOUTH CHINA UNIVERSITY OF TECHNOLOGY, Guangdong (CN)
Appl. No. 17/428,637
Filed by SOUTH CHINA UNIVERSITY OF TECHNOLOGY, Guangdong (CN)
PCT Filed Mar. 25, 2019, PCT No. PCT/CN2019/079466
§ 371(c)(1), (2) Date Aug. 5, 2021,
PCT Pub. No. WO2020/177163, PCT Pub. Date Sep. 10, 2020.
Claims priority of application No. 201910170800.0 (CN), filed on Mar. 7, 2019.
Prior Publication US 2022/0115998 A1, Apr. 14, 2022
Int. Cl. H03F 1/02 (2006.01); H03F 3/387 (2006.01); H03F 3/45 (2006.01)
CPC H03F 3/387 (2013.01) [H03F 3/45475 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A chopper amplifying circuit employing a negative impedance compensation technique, comprising: a differential input end, a first-level chopper switch, a negative impedance converting circuit, a first-level amplifying circuit, a second-level chopper switch, a second-level amplifying circuit, a differential output end, a negative feedback unit, and input capacitors, wherein two ports of the differential input end are respectively connected to two input terminals of the first-level chopper switch for inputting a differential voltage signal; two output terminals of the first-level chopper switch are respectively connected to two signal input ends of the first-level amplifying circuit through the input capacitors; two signal output ends of the first-level amplifying circuit are respectively connected to two input terminals of the second-level chopper switch, two output terminals of the second-level chopper switch are respectively connected to two signal input ends of the second-level amplifying circuit, and two signal output ends of the second-level amplifying circuit are respectively connected to two ports of the differential output end, and are also connected to a feedback input end of the first-level amplifying circuit through the negative feedback unit; and the negative impedance converting circuit is parallel-connected to the two signal input ends of the first-level amplifying circuit for reducing an equivalent input capacitance of the first-level amplifying circuit.