摘要 |
A calibration circuit for matching the output impedance of a driver by calibrating adjustments to the driver is described. The calibration circuit includes a driver circuit with a plurality of calibration transistors configured to receive a plurality of adjustment signals. The calibration circuit also includes a comparator circuit, and a binary searcher. The driver provides a signal corresponding to an output impedance to the comparator circuit. The output impedance signal is compared to a target impedance, and the comparator circuit then provides logic signals to the binary searcher representing whether the output impedance is greater than the target impedance. The binary searcher then selects a type of step size and count direction, in response to the logic signals, to count the number of steps for adjusting the calibration transistors of the driver.
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