Voltage to frequency converter for DAC test

In this paper a modified relaxation oscillator is proposed as the core of an analog to digital modulator for on chip signal extraction for test. The architecture uses digital current source generation and digital switching in place of active circuitry. The resulting design allows for high input sensitivity, robustness to component variation while occupying little silicon area. This paper provides solutions on the main challenges in implementing this modulator and how it may be integrated with a digital based tester.