All-digital ramp waveform generator for two-step single-slope ADC

Abstract

This paper presents an all-digital on-chip ramp waveform generator for an 8-bit single-slope ADC. The proposed ramp waveform generator consists of static CMOS digital circuits and is designed using standard cells aiming for the process portability. The proposed circuit realizes digitally-controlled ramp output and also realizes two step coarse-fine ramp waveform to speed up the single-slope analog-todigital conversion. The experimental results of the circuit simulation with random variation on 0.18 μm CMOS process demonstrate the feasibility of our ramp waveform generator and 8-bit two-step single-slope ADC with DNL within ±0.2LSB and INL within ±0.8LSB.

Design 8 Bit Analog Unit ADC Integrating Type Single Slope For Low Frequency Application

“…At that time, the clock will be enumerated as many as 2 N times and the result in the latch. Output of D0 -D7 will show the binary value of the input level captured by S/H [ 1 ] .…”