Abstract
The paper presents a continuous-time (CT) DeltaSigma
(∆Σ) analog-to-digital converter (ADC) using a current
output digital-to-analog converter (DAC) for the feedback. From
circuit analysis it is shown that using a current output DAC
makes it possible to relax the noise requirements of the 1st
integrator of the loopfilter, and thereby reduce the current
consumption. Furthermore, the noise of the current output DAC
being dependent on the ADC input signal level, enabling a
dynamic range that is larger than the peak signal-to-noise ratio
(SNR). The current output DAC is used in a 3rd order multibit
CT ∆Σ ADC for audio applications, designed in a 0.18 µm
CMOS process, with active-RC integrators, a 7-level Flash ADC
quantizer and current output DAC for the feedback. From
simulations the ADC achieves a dynamic range of 95.0 dB in the
audio band, with a current consumption of 284 µA for a 1.7 V
supply voltage; the resulting figure-of-merit is 262 fJ/conversion.
Original language | English |
---|---|
Title of host publication | Proceedings of ECCTD 2015 |
Number of pages | 4 |
Publisher | IEEE |
Publication date | 2015 |
ISBN (Print) | 978-1-4799-9877-7 |
DOIs | |
Publication status | Published - 2015 |
Event | 2015 European Conference on Circuit Theory and Design - Trondheim, Norway Duration: 24 Aug 2015 → 26 Aug 2015 Conference number: 22 |
Conference
Conference | 2015 European Conference on Circuit Theory and Design |
---|---|
Number | 22 |
Country/Territory | Norway |
City | Trondheim |
Period | 24/08/2015 → 26/08/2015 |
Keywords
- Delta-Sigma ADC
- Continuous-time
- Current output DAC
- Low power design