US 11,811,374 B1
Differential diode-based variable impedance modules
James Hoffman, Thousand Oaks, CA (US); and Florin Pera, Ottawa (CA)
Assigned to MARVELL ASIA PTE LTD, Singapore (SG)
Filed by MARVELL ASIA PTE LTD., Singapore (SG)
Filed on Sep. 13, 2022, as Appl. No. 17/943,578.
Application 17/943,578 is a continuation of application No. 16/878,434, filed on May 19, 2020, granted, now 11,451,201.
This patent is subject to a terminal disclaimer.
Int. Cl. H03F 3/45 (2006.01)
CPC H03F 3/45179 (2013.01) [H03F 3/4508 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A transimpedance amplifier comprising:
a first input switch comprising a first emitter terminal, a first base terminal coupled to a first input terminal of the transimpedance amplifier, and a first collector terminal coupled to a first output terminal of the transimpedance amplifier;
a second input switch comprising a second emitter terminal, a second base terminal coupled to a second input terminal of the transimpedance amplifier, and a second collector terminal coupled to a second output terminal of the transimpedance amplifier; and
a variable impedance module coupled to the first collector and the second collector terminals, the variable impedance module comprising a differential diode switch configured to provide analog control of a gain of the transimpedance amplifier at high frequencies by varying impedance between the first collector and the second collector terminals,
wherein the differential diode switch comprises at least four diodes arranged in a bridge including a first pair of series-connected diodes connected in parallel to a second pair of series-connected diodes, a plurality of capacitors connected to the bridge, and a current source configured to bias the diodes in the bridge to provide the analog control.