scholarly journals Design Strategies and Architectures for Ultra-Low-Voltage Delta-Sigma ADCs

Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1156
Author(s):  
Lorenzo Benvenuti ◽  
Alessandro Catania ◽  
Giuseppe Manfredini ◽  
Andrea Ria ◽  
Massimo Piotto ◽  
...  

The design of ultra-low voltage analog CMOS integrated circuits requires ad hoc solutions to counteract the severe limitations introduced by the reduced voltage headroom. A popular approach is represented by inverter-based topologies, which however may suffer from reduced finite DC gain, thus limiting the accuracy and the resolutions of pivotal circuits like analog-to-digital converters. In this work, we discuss the effects of finite DC gain on ultra-low voltage ΔΣ modulators, focusing on the converter gain error. We propose an ultra-low voltage, ultra-low power, inverter-based ΔΣ modulator with reduced finite-DC-gain sensitivity. The modulator employs a two-stage, high DC-gain, switched-capacitor integrator that applies a correlated double sampling technique for offset cancellation and flicker noise reduction; it also makes use of an amplifier that implements a novel common-mode stabilization loop. The modulator was designed with the UMC 0.18 μm CMOS process to operate with a supply voltage of 0.3 V. It was validated by means of electrical simulations using the CadenceTM design environment. The achieved SNDR was 73 dB, with a bandwidth of 640 Hz, and a clock frequency of 164 kHz, consuming only 200.5 nW. It achieves a Schreier Figure of Merit of 168.1 dB. The proposed modulator is also able to work with lower supply voltages down to 0.15 V with the same resolution and a lower power consumption despite of a lower bandwidth. These characteristics make this design very appealing in sensor interfaces powered by energy harvesting sources.

2021 ◽  
Vol 11 (2) ◽  
pp. 19
Author(s):  
Francesco Centurelli ◽  
Riccardo Della Sala ◽  
Pietro Monsurrò ◽  
Giuseppe Scotti ◽  
Alessandro Trifiletti

In this paper, we present a novel operational transconductance amplifier (OTA) topology based on a dual-path body-driven input stage that exploits a body-driven current mirror-active load and targets ultra-low-power (ULP) and ultra-low-voltage (ULV) applications, such as IoT or biomedical devices. The proposed OTA exhibits only one high-impedance node, and can therefore be compensated at the output stage, thus not requiring Miller compensation. The input stage ensures rail-to-rail input common-mode range, whereas the gate-driven output stage ensures both a high open-loop gain and an enhanced slew rate. The proposed amplifier was designed in an STMicroelectronics 130 nm CMOS process with a nominal supply voltage of only 0.3 V, and it achieved very good values for both the small-signal and large-signal Figures of Merit. Extensive PVT (process, supply voltage, and temperature) and mismatch simulations are reported to prove the robustness of the proposed amplifier.


2018 ◽  
Vol 27 (13) ◽  
pp. 1850206 ◽  
Author(s):  
Qingshan Yang ◽  
Peiqing Han ◽  
Niansong Mei ◽  
Zhaofeng Zhang

A 16.4[Formula: see text]nW, sub-1[Formula: see text]V voltage reference for ultra-low power low voltage applications is proposed. This design reduces the operating voltage to 0.8[Formula: see text]V by a BJT voltage divider and decreases the silicon area considerably by eliminating resistors. The PTAT and CTAT are based on SCM structures and a scaled-down [Formula: see text], respectively, to improve the process insensitivity. This work is fabricated in 0.18[Formula: see text][Formula: see text]m CMOS process with a total area of 0.0033[Formula: see text]mm2. Measured results show that it works properly for supply voltage from 0.8[Formula: see text]V to 2[Formula: see text]V. The reference voltage is 467.2[Formula: see text]mV with standard deviation ([Formula: see text]) being 12.2 mV and measured TC at best is 38.7[Formula: see text]ppm/[Formula: see text]C ranging from [Formula: see text]C to 60[Formula: see text]C. The total power consumption is 16.4[Formula: see text]nW under the minimum supply voltage at 27[Formula: see text]C.


Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1563
Author(s):  
Jae Kwon Ha ◽  
Chang Kyun Noh ◽  
Jin Seop Lee ◽  
Ho Jin Kang ◽  
Yu Min Kim ◽  
...  

In this work, a multi-mode radar transceiver supporting pulse, FMCW and CW modes was designed as an integrated circuit. The radars mainly detect the targets move by using the Doppler frequency which is significantly affected by flicker noise of the receiver from several Hz to several kHz. Due to this flicker noise, the long-range detection performance of the radars is greatly reduced, and the accuracy of range to the target and velocity is also deteriorated. Therefore, we propose a transmitter that suppresses LO leakage in consideration of long-range detection, target distance, velocity, and noise figure. We also propose a receiver structure that suppresses DC offset due to image signal and LO leakage. The design was conducted with TSMC 65 nm CMOS process, and the designed and fabricated circuit consumes a current of 265 mA at 1.2 V supply voltage. The proposed transmitter confirms the LO leakage suppression of 37 dB at 24 GHz. The proposed receiver improves the noise figure by about 20 dB at 100 Hz by applying a double conversion architecture and an image rejection, and it illustrates a DC rejection of 30 dB. Afterwards, the operation of the pulse, FMCW, and CW modes of the designed radar in integrated circuit was confirmed through experiment using a test PCB.


2021 ◽  
Vol 3 (4) ◽  
Author(s):  
S. Chrisben Gladson ◽  
Adith Hari Narayana ◽  
V. Thenmozhi ◽  
M. Bhaskar

AbstractDue to the increased processing data rates, which is required in applications such as fifth-generation (5G) wireless networks, the battery power will discharge rapidly. Hence, there is a need for the design of novel circuit topologies to cater the demand of ultra-low voltage and low power operation. In this paper, a low-noise amplifier (LNA) operating at ultra-low voltage is proposed to address the demands of battery-powered communication devices. The LNA dual shunt peaking and has two modes of operation. In low-power mode (Mode-I), the LNA achieves a high gain ($$S21$$ S 21 ) of 18.87 dB, minimum noise figure ($${NF}_{min.}$$ NF m i n . ) of 2.5 dB in the − 3 dB frequency range of 2.3–2.9 GHz, and third-order intercept point (IIP3) of − 7.9dBm when operating at 0.6 V supply. In high-power mode (Mode-II), the achieved gain, NF, and IIP3 are 21.36 dB, 2.3 dB, and 13.78dBm respectively when operating at 1 V supply. The proposed LNA is implemented in UMC 180 nm CMOS process technology with a core area of $$0.40{\mathrm{ mm}}^{2}$$ 0.40 mm 2 and the post-layout validation is performed using Cadence SpectreRF circuit simulator.


VLSI Design ◽  
2002 ◽  
Vol 15 (2) ◽  
pp. 547-553
Author(s):  
S. M. Rezaul Hasan ◽  
Yufridin Wahab

This paper explores the deterministic transistor reordering in low-voltage dynamic BiCMOS logic gates, for reducing the dynamic power dissipation. The constraints of load driving (discharging) capability and NPN turn-on delay for MOSFET reordered structures has been carefully considered. Simulations shows significant reduction in the dynamic power dissipation for the transistor reordered BiCMOS structures. The power-delay product figure-of-merit is found to be significantly enhanced without any associated silicon-area penalty. In order to experimentally verify the reduction in power dissipation, original and reordered structures were fabricated using the MOSIS 2 μm N-well analog CMOS process which has a P-base layer for bipolar NPN option. Measured results shows a 20% reduction in the power dissipation for the transistor reordered structure, which is in close agreement with the simulation.


Author(s):  
Priti Gupta ◽  
Sanjay Kumar Jana

This paper deals with the designing of low-power transconductance–capacitance-based loop filter. The folded cascode-based operational transconductance amplifier (OTA) is designed in this paper with the help of quasi-floating bulk MOSFET that achieved the DC gain of 88.61[Formula: see text]dB, unity gain frequency of 97.86[Formula: see text]MHz and power consumption of 430.62[Formula: see text][Formula: see text]W. The proposed OTA is compared with the exiting OTA structure which showed 19.50% increase in DC gain and 15.11% reduction in power consumption. Further, the proposed OTA is used for the designing of transconductance–capacitance-based loop filter that has been operated at [Formula: see text]3[Formula: see text]dB cut-off frequency of 30.12[Formula: see text]MHz with the power consumption of 860.90[Formula: see text][Formula: see text]W at the supply voltage of [Formula: see text][Formula: see text]V. The transistor-level simulation has been done in 0.18[Formula: see text][Formula: see text]m CMOS process.


Author(s):  
Ming-Cheng Liu ◽  
Paul C.-P. Chao ◽  
Soh Sze Khiong

In this paper a low power all-digital clock and data recovery (ADCDR) with 1Mhz frequency has been proposed. The proposed circuit is designed for optical receiver circuit on the battery-less photovoltaic IoT (Internet of Things) tags. The conventional RF receiver has been replaced by the visible light optical receiver for battery-less IoT tags. With this proposed ADCDR a low voltage, low power consumption & tiny IoT tags can be fabricated. The proposed circuit achieve the maximum bandwidth of 1MHz, which is compatible with the commercial available LED and light sensor. The proposed circuit has been fabricated in TSMC 0.18um 1P6M standard CMOS process. Experimental results show that the power consumption of the optical receiver is approximately 5.58uW with a supply voltage of 1V and the data rate achieves 1Mbit/s. The lock time of the ADCDR is 0.893ms with 3.31ns RMS jitter period.


Author(s):  
Wen-Yu Chen ◽  
Yi-Feng Zhang ◽  
Paul C.-P. Chao ◽  
Eka Fitrah Pribadi

Abstract The magnetic encoder (ME) always employs sensor passing through periodic and equal distance grating and then generates periodic quadrature scaling signals for displacement measurement. The phase is relative to the movement. To improve encoder accuracy or resolution, electronic interpolation technique had been developed to subdivide the phase of quadrature scaling signals. According to the trends, this paper proposed a specific method with excellent noise immunity characteristic and a complete calibration process to improve the accuracy of the system. The designed circuit is taped-out using TSMC 0.18-μm CMOS process, where the active area is 1643 μm × 1676 μm. The chip has the specification of 3.3 V supply voltage, 20 MHz clock frequency, and 0.0859 mW power consumption. The accuracy of the measurement system is 1.065um.


Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1410
Author(s):  
Luis Henrique Rodovalho ◽  
Orazio Aiello ◽  
Cesar Ramos Rodrigues

This paper proposes topological enhancements to increase voltage gain of ultra-low-voltage (ULV) inverter-based OTAs. The two proposed improvements rely on adoption of composite transistors and forward-body-biasing. The impact of the proposed techniques on performance figures is demonstrated through simulations of two OTAs. The first OTA achieves a 39 dB voltage gain, with a power consumption of 600 pW and an active area of 447 μm2. The latter allies the forward-body-bias approach with the benefit of the independently biased composite transistors. By combining both solutions, voltage gain is raised to 51 dB, consuming less power (500 pW) at the cost of an increased area of 727 μm2. The validation has been performed through post-layout simulations with the Cadence Analog Design Environment and the TSMC 180 nm design kit, with the supply voltage ranging from 0.3 V to 0.6 V.


Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 928 ◽  
Author(s):  
Taehoon Kim ◽  
Sivasundar Manisankar ◽  
Yeonbae Chung

Subthreshold SRAMs profit various energy-constrained applications. The traditional 6T SRAMs exhibit poor cell stability with voltage scaling. To this end, several 8T to 16T cell designs have been reported to improve the stability. However, they either suffer one of disturbances or consume large bit-area overhead. Furthermore, some cell options have a limited write-ability. This paper presents a novel 8T static RAM for reliable subthreshold operation. The cell employs a fully differential scheme and features cross-point access. An adaptive cell bias for each operating mode eliminates the read disturbance and enlarges the write-ability as well as the half-select stability in a cost-effective small bit-area. The bit-cell also can support efficient bit-interleaving. To verify the SRAM technique, a 32-kbit macro incorporating the proposed cell was implemented with an industrial 180 nm low-power CMOS process. At 0.4 V and room temperature, the proposed cell achieves 3.6× better write-ability and 2.6× higher dummy-read stability compared with the commercialized 8T cell. The 32-kbit SRAM successfully operates down to 0.21 V (~0.27 V lower than transistor threshold voltage). At its lowest operating voltage, the sleep-mode leakage power of entire SRAM is 7.75 nW. Many design results indicate that the proposed SRAM design, which is applicable to an aggressively-scaled process, might be quite useful in realizing cost-effective robust ultra-low voltage SRAMs.


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