US 9,813,040 B2
Resistor attenuator with switch distortion cancellation
Rajendrakumar Joish, Bangalore (IN)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Sep. 17, 2015, as Appl. No. 14/857,815.
Claims priority of application No. 4523/CHE/2014 (IN), filed on Sep. 17, 2014.
Prior Publication US 2016/0079949 A1, Mar. 17, 2016
Int. Cl. H01P 1/22 (2006.01); H03H 7/24 (2006.01); H03F 1/56 (2006.01); H03F 1/32 (2006.01); H03F 3/45 (2006.01)
CPC H03H 7/24 (2013.01) [H01P 1/22 (2013.01); H03F 1/3211 (2013.01); H03F 1/56 (2013.01); H03F 3/45475 (2013.01); H03F 2203/45151 (2013.01); H03F 2203/45594 (2013.01); H03F 2203/45614 (2013.01); H03F 2203/45616 (2013.01)] 20 Claims
OG exemplary drawing
 
9. A circuit, comprising
differential input nodes coupled to receive a differential input signal;
differential virtual ground circuitry to provide differential virtual ground nodes;
at least one attenuation stage including differential attenuation nodes, the differential attenuation nodes:
coupled to a respective differential input node through a respective resistance R,
coupled to a respective differential virtual ground node through a respective resistance kR and respective differential virtual ground switches Swf each with an on resistance Rswf, and
coupled to a differential ground node through respective resistances mR and respective differential ground switches Swp each with an on resistance Rswp;
Swp sized relative to Swf such that, when both Swp and Swf are conducting, a component current Ipnf of a current Ipn through Rswp and mR to a respective attenuation node and branching into kR and Rswf, matches, in phase and magnitude, a harmonic current Ifn from the respective differential virtual ground node through Rswf and kR to the respective differential attenuation node.