US 12,418,302 B2
Sigma-delta analogue to digital converter
Thierry Dominique Yves Cassagnes, Tournefeuille (FR); Francesco d'Esposito, Toulouse (FR); Pascal Sandrez, Toulouse (FR); Olivier Tico, St Lys (FR); and Simon Brule, Toulouse (FR)
Assigned to NXP USA, Inc., Austin, TX (US)
Filed by NXP USA, INC., Austin, TX (US)
Filed on Aug. 24, 2023, as Appl. No. 18/455,291.
Claims priority of application No. 22306305 (EP), filed on Sep. 2, 2022.
Prior Publication US 2024/0080035 A1, Mar. 7, 2024
Int. Cl. H03M 1/12 (2006.01); H03M 1/18 (2006.01); H03M 3/00 (2006.01)
CPC H03M 1/123 (2013.01) [H03M 1/183 (2013.01); H03M 3/458 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A sigma-delta ADC comprising:
a first-input-terminal configured to receive a first-analogue-input-signal;
a second-input-terminal configured to receive a second-analogue-input-signal;
a third-input-terminal configured to receive a third-analogue-input-signal;
a reference-terminal;
a first-amplifier-stage comprising:
a first-amplifier-first-input-terminal;
a first-amplifier-second-input-terminal;
a first-input-resistor connected in series between the first-input-terminal and a first-feedback-node;
a second-input-resistor connected in series between the second-input-terminal and a second-feedback-node;
a third-input-resistor connected in series between the third-input-terminal and a third-feedback-node;
a first-multiplexer-switch connected in series between the first-feedback-node and the first-amplifier-second-input-terminal;
a second-multiplexer-switch connected in series between the second-feedback-node and the first-amplifier-first-input-terminal;
a third-multiplexer-switch connected in series between the third-feedback-node and the first-amplifier-second-input-terminal;
a first-feedback-current-source having a first terminal and second terminal, wherein the second terminal is connected to the reference-terminal;
a second-feedback-current-source having a first terminal and second terminal, wherein the second terminal is connected to the reference-terminal;
a first-feedback-selection-switch connected in series between the first-feedback-node and the first terminal of the first-feedback-current-source;
a second-feedback-selection-switch connected in series between the second-feedback-node and the first terminal of the second-feedback-current-source; and
a third-feedback-selection-switch connected in series between the third-feedback-node and the first terminal of the first-feedback-current-source.