US 11,915,781 B2
Apparatuses and methods for ZQ calibration
Dongho Shin, Yongin-si (KR); Jungjune Park, Seoul (KR); Kyoungtae Kang, Seoul (KR); Chiweon Yoon, Seoul (KR); Junha Lee, Seoul (KR); and Byunghoon Jeong, Suwon-si (KR)
Assigned to SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed by SAMSUNG ELECTRONICS CO., LTD., Suwon-si (KR)
Filed on Oct. 5, 2022, as Appl. No. 17/938,214.
Claims priority of application No. 10-2021-0149952 (KR), filed on Nov. 3, 2021.
Prior Publication US 2023/0138561 A1, May 4, 2023
Int. Cl. G11C 7/10 (2006.01); H03K 19/00 (2006.01)
CPC G11C 7/1051 (2013.01) [H03K 19/0005 (2013.01); G11C 2207/2254 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
an input/output (I/O) circuit connected to a signal pin, the I/O circuit including a strong driver circuit and a weak driver circuit, wherein the strong driver circuit is stronger than the weak driver circuit;
an impedance control (ZQ) calibration circuit connected to a ZQ pin, and configured to perform ZQ calibration using a sweep code or a fixed code, the ZQ pin being connected to a ZQ resistor, the sweep code being updated in a calibration operation related to the ZQ pin, and the fixed code being stored in a register; and
a ZQ calibration control circuit connected to the I/O circuit and the ZQ calibration circuit, and configured to:
generate a ZQ calibration code signal according to ZQ calibration conditions, based on the sweep code or the fixed code,
select a driver circuit from among the strong driver circuit and the weak driver circuit based on the ZQ calibration conditions,
adjust a termination resistance of the signal pin by providing a ZQ calibration code related to the sweep code to the selected driver circuit, and
provide a ZQ calibration code related to the fixed code to an unselected circuit from among the strong driver circuit and the weak driver circuit.