<title>Voltage to frequency converter for DAC test</title>

Abstract

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.

A pipeline voltage-to-time converter for high resolution signal extraction off-chip

“…This method was prone to nonlinearity in the voltage waveform due to channel length modulation [8]. Instead of using a constant linear voltage waveform, we purpose to use a voltage staircase as the voltage reference to the comparator as shown below in Figure 5.…”

“…That assumed transistor level performance as described by equation (8). An ideal saturation current of 1.6A was used with a capacitor value of 80pF.…”