Impedance calibration circuits with adjustable reference voltages
AssigneeSK hynix Inc.
InventorDong Wook Jang
Life of this patent
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Abstract
An impedance calibration circuit includes a first calibration voltage driver configured to operate in response to a first enable signal, compare a first calibration voltage signal with a first reference voltage signal, and drive the first calibration voltage signal, a first control code generator configured to operate in response to a second enable signal, compare the first calibration voltage signal with a first target voltage signal, and generate a first control code signal, and a first reference voltage generator configured to generate the first reference voltage signal in response to the first control code signal.
Claims21
An impedance calibration circuit, comprising:
- a first calibration voltage driver configured to operate in response to a first enable signal, compare a first calibration voltage signal with a first reference voltage signal, and drive the first calibration voltage signal according to a comparison result;
- a first control code generator configured to operate in response to a second enable signal, compare the first calibration voltage signal with a first target voltage signal, and generate a first control code signal;
- and
- a first reference voltage generator configured to generate the first reference voltage signal in response to the first control code signal,
- wherein a voltage level of the first reference voltage signal is controlled by the first control code signal, and
- wherein the first calibration voltage signal is induced at a pad coupled to an external resistor.
An impedance calibration circuit, comprising:
- a first calibration voltage driver configured to operate in response to a first enable signal, compare a first calibration voltage signal with first and second reference voltage signals, and drive the first calibration voltage signal according to a comparison result;
- a first control code generator configured to operate in response to a second enable signal, compare the first calibration voltage signal with a first target voltage signal, and generate a first control code signal;
- and
- a first reference voltage generator configured to generate the first and second reference voltage signals in response to the first control code signal,
- wherein a voltage level of the first and second reference voltage signals, respectively, is controlled by the first control code signal, and
- wherein the first calibration voltage signal is induced at a pad coupled to an external resistor.
Dependencies are inferred from the claim text.