US 12,489,410 B2
Common-mode feedback
Dominik Przyborowski, Trondheim (NO)
Assigned to Nordic Semiconductor ASA, Trondheim (NO)
Appl. No. 18/027,363
Filed by Nordic Semiconductor ASA, Trondheim (NO)
PCT Filed Sep. 22, 2021, PCT No. PCT/EP2021/076105
§ 371(c)(1), (2) Date Mar. 20, 2023,
PCT Pub. No. WO2022/063849, PCT Pub. Date Mar. 31, 2022.
Claims priority of application No. 2014963 (GB), filed on Sep. 22, 2020.
Prior Publication US 2023/0387874 A1, Nov. 30, 2023
Int. Cl. H03F 3/45 (2006.01); H03F 1/34 (2006.01)
CPC H03F 3/45663 (2013.01) [H03F 1/342 (2013.01); H03F 3/45183 (2013.01); H03F 2200/261 (2013.01); H03F 2203/45134 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A common-mode feedback circuit for a fully differential amplifier, said common-mode feedback circuit comprising first, second, and third transistors, each having a respective drain terminal, source terminal, gate terminal, and back-gate terminal, wherein the common mode feedback circuit is arranged such that:
the drain terminal of the first transistor and the gate terminals of the first, second, and third transistors are connected together at a bias current terminal;
the drain terminals of the second and third transistors are connected together at a tail current terminal; and
the source terminals of the first, second, and third transistors are connected together;
wherein the back-gate terminal of the first transistor is arranged to receive a common-mode reference voltage input, the back-gate terminal of the second transistor is arranged to receive a positive output voltage from the fully differential amplifier, and the back-gate terminal of the third transistor is arranged to receive a negative output voltage from the fully differential amplifier.