US 11,863,169 B2
Current-mode circuits and calibration thereof
Saul Darzy, Maidenhead (GB); and Ozcan Tuncturk, Maidenhead (GB)
Assigned to SOCIONEXT INC., Kanagawa (JP)
Filed by Socionext Inc., Kanagawa (JP)
Filed on Jun. 27, 2022, as Appl. No. 17/850,202.
Claims priority of application No. 21188083 (EP), filed on Jul. 27, 2021.
Prior Publication US 2023/0036535 A1, Feb. 2, 2023
Int. Cl. H03M 1/66 (2006.01); H03K 17/687 (2006.01); H03M 1/12 (2006.01); H03F 3/45 (2006.01)
CPC H03K 17/687 (2013.01) [H03M 1/12 (2013.01); H03M 1/66 (2013.01); H03F 3/45071 (2013.01); H03F 2200/156 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A current-mode circuit, comprising:
a plurality of switch units, each of the plurality of switch units comprising a field-effect transistor connected in series with an impedance and configured to carry a given current, wherein for each of the plurality of switch units or for at least one of the plurality of switch units the impedance is a variable impedance;
an adjustment circuit configured, for each of the plurality of switch units or for the at least one of the plurality of switch units, to adjust an impedance of the variable impedance to calibrate a predetermined property of that switch unit which is dependent on the field-effect transistor;
a shared current source; and
a shared measurement node,
wherein:
for each of the plurality of switch units, a serial connection of the field-effect transistor and the impedance is further connected in series with the shared current source, the shared current source defining the given current, a node between the serial connection and the shared current source being the shared measurement node, and a voltage at the shared measurement node being a measurement voltage, and
the adjustment circuit comprises a comparator configured, for each of the plurality of switch units or for the at least one of the plurality of switch units, to compare the measurement voltage with a reference voltage, and configured to adjust the impedance of the variable impedance concerned based on the comparison to bring the measurement voltage into or towards a target relationship with the reference voltage.