Apparatus for calibrating off-chip driver/on-die termination circuits
AssigneeSanDisk Technologies LLC
InventorHitoshi Miwa
Life of this patent
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Abstract
An impedance calibration circuit is provided for off-chip driver/on-die termination circuits. The impedance calibration circuit includes a first circuit that includes first PMOS transistors coupled in parallel between a power supply terminal and a first output terminal, second PMOS transistors coupled in parallel between the power supply terminal and a second output terminal, first NMOS transistors coupled in parallel between the second output terminal and a GROUND terminal, a third PMOS transistor coupled in parallel with the first PMOS transistors between a power supply terminal and a first output terminal, and a second NMOS transistor coupled in parallel with the first NMOS transistors between the second output terminal and a GROUND terminal.
Claims24
1-23. (canceled)
An impedance calibration circuit comprising:
- a plurality of replica circuits, each of the replica circuits having a corresponding unique configuration;
- and
- a selector circuit configured to select, based on one or more of process, temperature and power supply data, one of the replica circuits to match a reference impedance.
A system comprising:
- an input-output circuit;
- and
- an impedance calibration circuit configured to control an impedance of the input-output circuit, the impedance calibration circuit comprising:
- a plurality of replica circuits, each of the plurality of replica circuits configured to target a corresponding unique resistance;
- and
- a selector circuit configured to select, based on one or more of process, temperature and power supply data, one of the replica circuits to match a reference impedance.
A method comprising:
- providing a plurality of replica circuits;
- configuring each of the replica circuits to target a corresponding unique impedance;
- selecting, based on one or more of process, temperature and power supply data, one of the plurality of replica circuits;
- and
- using the selected replica circuit to match a reference impedance.
Dependencies are inferred from the claim text.