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US 9,543,952 B2Granted
Semiconductor memory device and a method of operating the same
AssigneeSamsung Electronics Co., Ltd.
InventorKi Won Lee
Life of this patent
Estimating the term…
Abstract
A semiconductor memory device includes a ZQ calibration unit configured to generate an output high level voltage (VOH) code according to a VOH control code obtained from a result of comparing a reference voltage with a first VOH; and an output driver configured to generate a data signal having a second VOH determined by the VOH code. The VOH control code includes a pull-up VOH control code and a pull-down VOH control code and the VOH code includes a pull-up VOH code and a pull-down VOH code.
Claims13
A semiconductor memory device, comprising:
- a ZQ calibration unit configured to generate an output high level voltage (VOH) code according to a VOH control code obtained from a result of comparing a reference voltage with a first VOH, wherein the reference voltage is calibrated according a VOH difference between different memory devices;
- and
- an output driver configured to generate a data signal having a second VOH determined by the VOH code,
- wherein the VOH control code comprises a pull-up VOH control code and a pull-down VOH control code and the VOH code comprises a pull-up VOH code and a pull-down VOH code.
1 more element
A semiconductor memory device, comprising:
- a data output circuit configured to perform ZQ calibration according to an output high level voltage (VOH) change request signal or a test mode signal and output a data signal whose VOH has been changed,
- the data output circuit including a ZQ calibration control unit configured to generate a VOH control code corresponding to information of the VOH change request signal or the test mode signal, the information indicating whether to increase or decrease the VOH, wherein the information of the VOH change request signal or the test mode signal is indicative of a difference between a first reference voltage of a first memory device and a second reference voltage of a second memory device exceeding a first threshold.
Dependencies are inferred from the claim text.