Back to results
US 11,705,888 B2Granted
ZQ calibration using current source
AssigneeMicron Technology, Inc.
InventorsYasuo Satoh, Hiroki Takahashi, Shuichi Tsukada, Yuan He
Life of this patent
Estimating the term…
Abstract
A memory device includes a terminal calibration circuit having at least one of a pull-down circuit or a pull-up circuit used in calibrating an impedance of a data bus termination. The memory device also includes a reference calibration circuit configured to generate a calibration current. The terminal calibration circuit can be configured to program an impedance of the least one of a pull-down circuit or a pull-up circuit based on the calibration current.
Claims18
An apparatus, comprising:
- a current source circuit configured to generate a reference current that is at a constant value for a predetermined temperature range;
- a reference calibration circuit configured to generate a calibration current based on the reference current;
- and
- a terminal calibration circuit for calibrating a data bus termination based on the calibration current,
- wherein the reference calibration circuit includes a programmable resistance circuit and the reference calibration circuit is configured to program a resistance of the programmable resistance circuit using the reference current, and
- wherein the calibration current is based on the resistance of the programmable resistance circuit.
3 more elements
An apparatus, comprising:
- a current source circuit configured to generate a reference current that is at a constant value for a predetermined temperature range;
- a reference calibration circuit configured to generate a calibration current based on the reference current;
- and
- a terminal calibration circuit for calibrating a data bus termination based on the calibration current,
- wherein the reference calibration circuit includes a current mirror circuit that is configured to provide the calibration current, the current mirror circuit also configured to provide a first current to a reference resistance circuit having a predetermined impedance,
- wherein the current mirror circuit is further configured to adjust the first current to maintain an output voltage of the reference resistance circuit at a predetermined reference value, and
- wherein the calibration current is based on the first current.
4 more elements
A method, comprising:
- generating a reference current that is at a constant value for a predetermined temperature range;
- generating a calibration current based on the reference current;
- programming an impedance of a terminal calibration circuit based on the calibration current, the terminal calibration circuit configured to calibrate a data bus termination, and
- programming a resistance of a programmable resistance circuit based on the reference current,
- wherein the generating of the calibration current is based on the resistance of the programmable resistance circuit.
2 more elements
A method, comprising:
- generating a reference current that is at a constant value for a predetermined temperature range;
- generating a calibration current based on the reference current;
- programming an impedance of a terminal calibration circuit based on the calibration current, the terminal calibration circuit configured to calibrate a data bus termination,
- providing a first current to a reference resistance circuit having a predetermined impedance;
- and
- controlling the first current to maintain an output voltage of the reference resistance circuit at a predetermined reference value,
- wherein the calibration current is based on the first current.
4 more elements
Dependencies are inferred from the claim text.