A 10-bit Pulse Width Modulation Based Analog to Digital Converter

A 10-bit pulse width modulated analog to digital converter (ADC) is proposed in this paper. The ADC is based on simple analog blocks and designed to operate as a back-end digital interface for sensor readout circuits. Our design incorporates simple blocks such as a chopped comparator and a 10-bit digital counter with few switches and passive elements to implement a very functional and versatile ADC for bridge readout circuits. Designed and simulated in 0.18µm CMOS process, the ADC consumes 55µA supply current and achieves an linearity of around 9-bits without any jitter compensation. The simulated DNL error is less than ±1 LSB for this ADC.