US 12,394,453 B2
Multi-mode compatible ZQ calibration circuit in memory device
Hang Song, Wuhan (CN); Daesik Song, Wuhan (CN); and Lin Yang, Wuhan (CN)
Assigned to YANGTZE MEMORY TECHNOLOGIES CO., LTD., Wuhan (CN)
Filed by YANGTZE MEMORY TECHNOLOGIES CO., LTD., Wuhan (CN)
Filed on Dec. 4, 2023, as Appl. No. 18/528,395.
Application 18/528,395 is a division of application No. 17/483,244, filed on Sep. 23, 2021, granted, now 11,875,873.
Application 17/483,244 is a continuation of application No. PCT/CN2021/082661, filed on Mar. 24, 2021.
Prior Publication US 2024/0105238 A1, Mar. 28, 2024
Int. Cl. G11C 7/10 (2006.01); G11C 16/06 (2006.01)
CPC G11C 7/1048 (2013.01) [G11C 16/06 (2013.01); G11C 2207/2254 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method for ZQ calibration, comprising:
according to a first double rate data (DDR) standard comprising a DDR3 mode, the method comprising:
comparing a first voltage of a first resistor input with a first voltage of a first selectable voltage source by a first comparator;
comparing a first voltage of a first middle point with a first voltage of a second selectable voltage source by a second comparator;
calibrating a first pull-up driver based on a first comparison of the first comparator, wherein the first pull-up driver connected to the first resistor input; and
calibrating a first pull-down driver based on a second comparison of the second comparator, wherein the first pull-down driver connected to the first middle point; and
according to a second DDR standard different from the first DDR standard and comprising an LPDDR4 mode, the method comprising:
comparing a second voltage of the first resistor input with a second voltage of the first selectable voltage source by the first comparator, wherein the second voltage of the first selectable voltage source is different from the first voltage of the first selectable voltage source;
comparing a second voltage of a second middle point with a second voltage of the second selectable voltage source by the second comparator, wherein the second voltage of the second selectable voltage source is different from the first voltage of the second selectable voltage source;
calibrating a second pull-up driver based on a third comparison of the first comparator, wherein the second pull-up driver connected to the first resistor input; and
calibrating a second pull-down driver based on a fourth comparison of the second comparator, wherein the second pull-down driver connected to the second middle point.