US 11,881,825 B2
Trimming operational amplifiers
Vadim Valerievich Ivanov, Tucson, AZ (US); Munaf Hussain Shaik, Tucson, AZ (US); Srinivas Kumar Pulijala, Tucson, AZ (US); Patrick Forster, Freising (DE); and Jerry Lee Doorenbos, Tucson, AZ (US)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by Texas Instruments Incorporated, Dallas, TX (US)
Filed on Dec. 29, 2020, as Appl. No. 17/136,073.
Prior Publication US 2022/0209730 A1, Jun. 30, 2022
Int. Cl. H03F 3/45 (2006.01); H03M 1/66 (2006.01); H03M 1/38 (2006.01)
CPC H03F 3/45475 (2013.01) [H03M 1/38 (2013.01); H03M 1/66 (2013.01); H03F 2200/375 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A system comprising:
an operational amplifier (op-amp) with adjustable operational parameters, and a trimming module;
wherein the trimming module adjusts the operational parameters of the op-amp based on a memory value to compensate for an offset voltage of the op-amp;
wherein the trimming module comprises a successive approximation register (SAR) logic that controls the memory value, the SAR logic being configured to detect a given memory value that causes an output voltage of the op-amp to be within a predetermined voltage interval when applying a predetermined common mode voltage to inverting and non-inverting inputs of the op-amp; and
wherein the SAR logic comprises conducting a first number of iterations for determining coarse bits of the memory value and conducting a second number of iterations for determining remaining fine bits of the memory value, wherein the first number of iterations are conducted at a first clock cycle duration, and wherein the second number of iterations are conducted at a second clock cycle duration, the first clock cycle duration being shorter than the second clock cycle duration.