US 12,413,242 B2
Reconfigurable analog-to-digital converter
Kannan Aryaperumal Sankaragomathi, Waterloo (CA); and Johan Peter Vanderhaegen, Cupertino, CA (US)
Assigned to Google LLC, Mountain View, CA (US)
Appl. No. 18/254,204
Filed by Google LLC, Mountain View, CA (US)
PCT Filed Dec. 21, 2020, PCT No. PCT/US2020/066407
§ 371(c)(1), (2) Date May 24, 2023,
PCT Pub. No. WO2022/139791, PCT Pub. Date Jun. 30, 2022.
Prior Publication US 2024/0007127 A1, Jan. 4, 2024
Int. Cl. H03M 1/12 (2006.01); H03M 1/08 (2006.01); H03M 1/16 (2006.01); H03M 3/00 (2006.01)
CPC H03M 3/426 (2013.01) [H03M 1/0854 (2013.01); H03M 1/16 (2013.01); H03M 3/498 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a reconfigurable analog-to-digital converter (ADC), the reconfigurable ADC configured to selectively support at least two different resolution settings, the reconfigurable ADC including:
a successive-approximation-register (SAR) ADC, the SAR ADC configured to:
perform a first cycle of an N-bit analog-to-digital conversion of an analog input voltage to generate an N-bit digital output, the N-bit analog-to-digital conversion including a conversion noise and a residual voltage after the first cycle of the N-bit analog-to-digital conversion; and
amplify a difference in the analog input voltage between two close time intervals;
a noise-canceling circuit configured to lower the conversion noise by sampling the analog input voltage after amplifying the difference in the analog input voltage; and
a noise-shaping circuit configured to add or subtract the residual voltage from the first cycle to a second cycle of the N-bit analog-to-digital conversion to reduce a quantization noise of the second cycle of the N-bit analog-to-digital conversion, the reconfigurable ADC being configured to selectively operate in one of at least two different modes of operation that comprise at least two of:
a first mode of operation, the first mode of operation configured to use the SAR ADC, the noise-canceling circuit, and the noise-shaping circuit;
a second mode of operation, the second mode of operation configured to use the SAR ADC and the noise-canceling circuit;
a third mode of operation, the third mode of operation configured to use the SAR ADC and the noise-canceling circuit; and
a fourth mode of operation, the fourth mode of operation configured to use the SAR ADC.