Synaptics Incorporated
OSCILLATOR TEMPERATURE COEFFICIENT ADJUSTMENT

Abstract:

An oscillator circuit is disclosed. The oscillator circuit includes: oscillator transistors including gates; adjustment transistors coupled to the gates; a differential output coupled to the oscillator transistors; a switch configured to set an oscillation frequency of the differential output by driving: a first current including a first portion of a main current through at least one of the oscillator transistors; and a second current including a second portion of the main current through at least one of the adjustment transistors; a first set of auxiliary current sources configured to adjust a temperature coefficient of the oscillator circuit by driving a first set of auxiliary currents through the oscillator transistors; and a second set of auxiliary current sources configured to maintain the oscillation frequency of the differential output by driving, in response to driving the first set of auxiliary currents, a second set of auxiliary currents though the adjustment transistors.