Conference paper
A 10 MHz Bandwidth Continuous-Time Delta-Sigma Modulator for Portable Ultrasound Scanners
A fourth-order 1-bit continuous-time delta-sigma modulator designed in a 65 nm process for portable ultrasound scanners is presented in this paper. The loop filter consists of RCintegrators, with programmable capacitor arrays and resistors, and the quantizer is implemented with a high-speed clocked comparator and a pull-down clocked latch.
The feedback signal is generated with voltage DACs based on transmission gates. Using this implementation, a small and low-power solution required for portable ultrasound scanner applications is achieved. The modulator has a bandwidth of 10 MHz with an oversampling ratio of 16 leading to an operating frequency of 320 MHz.
The design occupies an area of 0.0175 mm2 and achieves a SNR of 45 dB consuming 489 µA at a supply voltage of 1.2 V; the resulting FoM is 197 fJ/conversion. The results are based on simulations with extracted parasitics including process and mismatch variations.
| Language: | English |
|---|---|
| Publisher: | IEEE |
| Year: | 2016 |
| Pages: | 1-5 |
| Proceedings: | 2016 IEEE Nordic Circuits and Systems Conference |
| ISBN: | 1509010955 , 1509010963 , 9781509010950 and 9781509010967 |
| Types: | Conference paper |
| DOI: | 10.1109/NORCHIP.2016.7792902 |
| ORCIDs: | Llimos Muntal, Pere , Jørgensen, Ivan Harald Holger and Bruun, Erik |
Capacitors Latches Logic gates Modulation Power demand RC circuits RC-integrators Signal to noise ratio Ultrasonic imaging bandwidth 10 MHz biomedical ultrasonics continuous time filters continuous-time delta-sigma modulator current 489 muA delta-sigma modulation digital-analogue conversion feedback signal filters flip-flops frequency 320 MHz high-speed clocked comparator loop filter portable ultrasound scanners programmable capacitor arrays pull-down clocked latch size 0.0175 mm size 65 nm transmission gates ultrasonic imaging voltage 1.2 V voltage DAC
