Ahead of Print article · Journal article
34.3 fJ/conv.-step 8 MHz Bandwidth 4th-Order Pseudo-Differential Ring-Amplifier Based Continuous-Time Delta-Sigma ADC in 65 nm
This work presents two pseudo-differential ring amplifiers suitable for continuous-time operation as analternative to traditional amplifiers. The designs retain the advantages of ring amplifiers, scale with process technology and do not require a periodic reset. The ring amplifiers are designed to operate in an integrator configuration and they use different methods to achieve stability in continuous time.
A prototype was fabricatedin 65 nm CMOS containing two versions of a continuous-time deltasigma ADC using the two ring amplifiers presented. The ADCs consist of a 4th-order loop filter with optimized zeros, a singlebit quantizer that operates at a sampling frequency of 320 MHz and a DAC. The best design proposed achieves a measured peak SNDR of 50.6 dB for an 8 MHz bandwidth, a DR of 53.2 dB and consumes 152 µW at a supply of 1.1 V.
The obtained figure of merit is 34.3 fJ/conv.-step which outperforms state-of-the-art delta-sigma ADCs in that specification range and is 77% superior to its traditional OTA-based ADC counterpart.
Language: | English |
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Publisher: | IEEE |
Year: | 2020 |
Pages: | 198-201 |
ISSN: | 25739603 |
Types: | Ahead of Print article and Journal article |
DOI: | 10.1109/LSSC.2019.2910468 |
ORCIDs: | Llimos Muntal, Pere and Jørgensen, Ivan Harald Holger |
Analog to digital converter CMOS CMOS analogue integrated circuits CT delta-sigma ADC Circuit stability Distortion Inverters Scalability Stability criteria Transistors analogue-digital conversion bandwidth 8 MHz continuous time continuous-time (CT) continuous-time operation delta-sigma ADCs delta-sigma modulation delta–sigma differential amplifiers digital-to-analog converter figure of merit filters fourth-order loop filter fourth-order pseudodifferential ring-amplifier-based continuous-time delta-sigma ADC frequency 320.0 MHz integrated circuit design integrator configuration operational amplifiers oversampled process technology quantisation (signal) ring amplifiers (RAs) signal-to-noise-distortion ratio single-bit quantizer size 65 nm traditional amplifiers traditional operational transconductance amplifier-based ADC voltage 1.1 V