Abstract
This work describes a hybrid incremental ADC (IADC) with two-capacitor (2-C) successive-approximation registers (SAR) extended counting in two-step operation to achieve high resolution data conversion. The circuits in the first step is acting as a first-order incremental analog-to-digital converter (IADC). Finite impulse response (FIR) DAC is incorporated in the loop filter to reduce the transient voltage step. It is reconfigured as a 2-C SAR to perform extended counting technique in the second step. Only one opamp is re-used in both steps. The hardware is prototyped in 0.18~mu textm CMOS technology, and the hybrid ADC accomplishes a measured DR / SNR / SNDR of 100.2 / 97.1 / 96.6 dB and an input signal bandwidth of 1.2 kHz. Operated at 1.5-V, it consumes 33.2~mu textW , and this achieves a Walden figure-of-merit (FoM) of 0.25 pJ/conversion-step and Schreier FoM of 175.8 dB.
| Original language | English |
|---|---|
| Article number | 9431347 |
| Pages (from-to) | 2890-2899 |
| Number of pages | 10 |
| Journal | IEEE Transactions on Circuits and Systems I: Regular Papers |
| Volume | 68 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 2021 |
Keywords
- analog-to-digital converter (ADC)
- binary search
- Delta sigma (ΔΣ) modulator
- extended counting
- FIR DAC
- incremental data converters
- infinite impulse response
- measurement and instrumentation
- multi-stage noise shaping (MASH)
- multi-step
- multi-step incremental ADC
- sensor interface
- successive approximation register (SAR)
- time-domain analysis
- two step
- two-capacitor