CALIBRATING FOR ON-RESISTANCE MISMATCH OF DIGITAL-TO-ANALOG CONVERTER (DAC) SWITCHES

摘要

Certain aspects of the present disclosure provide methods and apparatus for setting a voltage level for controlling at least one of a first switch or a second switch, such that an on-resistance of the first switch matches an on-resistance of the second switch. One example circuit generally includes a third switch configured to replicate the first switch and a first cascode device connected in cascode with the third switch; a first amplifier configured to drive the first cascode device; a fourth switch configured to replicate the second switch; a second cascode device connected in cascode with the fourth switch; a second amplifier configured to drive the second cascode device; and a third amplifier configured to compare a voltage at a node coupled to the first and second cascode devices with a reference potential and to control the third switch based on the comparison to set the voltage level.

主权项

1. A circuit for setting a voltage level for controlling at least one of a first switch or a second switch, such that an on-resistance of the first switch matches an on-resistance of the second switch, the circuit comprising:
a third switch configured to replicate the first switch; a first cascode device connected in cascode with the third switch; a first amplifier configured to drive the first cascode device; a fourth switch configured to replicate the second switch; a second cascode device connected in cascode with the fourth switch; a second amplifier configured to drive the second cascode device; and a third amplifier configured to:
compare a voltage at a node coupled to the first and second cascode devices with a reference potential; andcontrol the third switch based on the comparison to set the voltage level.