US 11,689,831 B2
Image sensor and analog-to-digital converter
Taehee Cho, San Jose, CA (US)
Assigned to SK hynix Inc., Gyeonggi-do (KR)
Filed by SK hynix Inc., Gyeonggi-do (KR)
Filed on May 24, 2021, as Appl. No. 17/328,372.
Claims priority of provisional application 63/094,409, filed on Oct. 21, 2020.
Prior Publication US 2022/0124278 A1, Apr. 21, 2022
Int. Cl. H04N 25/772 (2023.01); H03M 1/56 (2006.01); H04N 25/65 (2023.01); H04N 25/75 (2023.01); H04N 25/709 (2023.01); H04N 25/778 (2023.01)
CPC H04N 25/772 (2023.01) [H03M 1/56 (2013.01); H04N 25/65 (2023.01); H04N 25/709 (2023.01); H04N 25/75 (2023.01); H04N 25/778 (2023.01)] 12 Claims
OG exemplary drawing
 
1. An image sensor, comprising:
a pixel outputting a pixel signal;
a ramp voltage generation circuit suitable for generating a ramp voltage that changes at a first slope in a first section and generating the ramp voltage that changes at a second slope having a greater absolute value than the first slope in a second section following the first section;
an operation amplifier suitable for comparing the pixel signal with the ramp voltages during the first section and the second section; and
a counter circuit suitable for generating a digital code corresponding to the pixel signal in response to an output of the operation amplifier,
wherein the counter circuit generates the digital code by counting a clock until the output of the operation amplifier transitions in the first section, and
wherein when the output of the operation amplifier does not transition in the first section, the counter circuit generates the digital code by counting the clock until the output of the operation amplifier transitions in the second section.