US 11,867,750 B2
Process variation detection circuit and process variation detection method
Shengcheng Deng, Hefei (CN); Chia-Chi Hsu, Hefei (CN); and Anping Qiu, Hefei (CN)
Assigned to CHANGXIN MEMORY TECHNOLOGIES INC., Hefei (CN)
Appl. No. 17/595,268
Filed by CHANGXIN MEMORY TECHNOLOGIES, INC., Hefei (CN)
PCT Filed Jul. 8, 2021, PCT No. PCT/CN2021/105325
§ 371(c)(1), (2) Date Nov. 12, 2021,
PCT Pub. No. WO2022/134544, PCT Pub. Date Jun. 30, 2022.
Claims priority of application No. 202011550999.9 (CN), filed on Dec. 24, 2020.
Prior Publication US 2023/0057198 A1, Feb. 23, 2023
Int. Cl. G01R 31/28 (2006.01)
CPC G01R 31/2884 (2013.01) 5 Claims
OG exemplary drawing
 
1. A process variation detection circuit, arranged in a chip, and comprising:
a first ring oscillator, wherein a first number of auxiliary elements of a preset type are arranged between two adjacent inverters of the first ring oscillator; and
a second ring oscillator, wherein a second number of auxiliary elements of a preset type are arranged between two adjacent inverters of the second ring oscillator, the second number is larger than the first number;
wherein, a number of the inverters of the first ring oscillator is the same as a number of the inverters of the second ring oscillator; a type and a size of a transistor of the first ring oscillator are the same as a type and a size of a transistor of the second ring oscillator; and a type and a connection mode of each of the auxiliary elements correspond to element parameters to be measured of the chip.