Stabilization of Electrostatic Actuators Through Variable Gain Amplifier

2012 ◽  
Author(s):  
Sangtak Park ◽  
Eihab Abdel-Rahman
Keyword(s):  
Feedback Loop ◽  
Bottom Electrode ◽  
Input Voltage ◽  
Parasitic Capacitance ◽  
Variable Gain Amplifier ◽  
Voltage Gain ◽  
Electrostatic Actuator ◽  
Electrostatic Actuators ◽  
Variable Gain ◽  
Drive Circuit

In the presence of high parasitic capacitance, conventional electrostatic actuation methods fail to drive an electrostatic actuator beyond its pull-in point. Although the resonant drive circuit is able to extend the operation range of an electrostatic actuator further at a much lower input voltage, an electrostatic actuator coupled with the resonant drive circuit also undergoes pull-in in the presence of high parasitic capacitance compared to the circuit’s quality factor. To improve its robustness to high parasitic capacitance, we design a variable gain amplifier that reduces voltage gain as an electrostatic actuator moves towards its bottom electrode: the increase in the impedance of the resonant drive circuit reduces voltage gain of a variable gain amplifier through its positive feedback loop, while its negative feedback stabilizes its operation.

scholarly journals Low Voltage Electrostatic Actuation and Displacement Measurement Through Resonant Drive Circuit

2012 ◽  
Author(s):  
Sangtak Park ◽  
Eihab Abdel-Rahman
Keyword(s):  
Measurement Method ◽  
Low Voltage ◽  
Supply Voltage ◽  
Numerical Models ◽  
Actuation Voltage ◽  
Input Voltage ◽  
Electrostatic Actuators ◽  
Mems Technology ◽  
Drive Circuit ◽  
The Impact

Most electrostatic actuators fabricated by MEMS technology require high actuation voltage and suffer from the pull-in phenomenon that limits the operation range. We present an amplitude-modulated resonant drive circuit to drive electrostatic actuators at much lower supply voltage than that of conventional actuators to extend their operation range. Analytical and numerical models facilitate stability analysis of electrostatic actuators coupled with the resonant drive circuit. We study the impact of parasitic capacitance and the quality factor of the resonant drive circuit on the operation range of electrostatic actuators. Furthermore, we present a new method to measure the displacement of electrostatic actuators by sensing the phase delay of the actuation voltage with respect to the input voltage. This measurement method allows us to easily incorporate feedback control into existing electrostatic actuators without any modification to the actuator itself.

130 nm CMOS Bulk-Driven Variable Gain Amplifier for Low-Voltage Applications

2017 ◽  
Vol 26 (08) ◽  
pp. 1740003 ◽  
Author(s):  
Daniel Arbet ◽  
Viera Stopjaková ◽  
Martin Kováč ◽  
Lukáš Nagy ◽  
Matej Rakús ◽  
...  
Keyword(s):  
Low Voltage ◽  
Supply Voltage ◽  
Input Voltage ◽  
Cmos Technology ◽  
Variable Gain Amplifier ◽  
Voltage Range ◽  
Variable Gain ◽  
Wide Scale ◽  
Simulation Results ◽  
Low Supply Voltage

In this paper, a variable gain amplifier (VGA) designed in 130 nm CMOS technology is presented. The proposed amplifier is based on the bulk-driven (BD) design approach, which brings a possibility to operate with low supply voltage. Since the supply voltage of only 0.6 V is used for the amplifier to operate, there is no risk of latch-up event that usually represents the main drawback of the BD circuit systems. BD transistors are employed in the input differential stage, which makes it possible to operate in rail-to-rail input voltage range. Achieved simulation results indicate that gain of the proposed VGA can be varied in a wide scale, which together with the low supply voltage feature make the proposed amplifier useful for low-voltage and low-power applications. An additional circuit responsible for maintaining the linear-in-decibel gain dependency of the VGA is also addressed. The proposed circuit block avails arbitrary shaping of the curve characterizing the gain versus the controlling voltage dependency.

scholarly journals Design of a Sampler circuit for Flash ADC using 45nm Technology

2019 ◽  
Vol 9 (2) ◽  
pp. 5363-5367
Keyword(s):  
Low Power ◽  
High Performance ◽  
Input Voltage ◽  
Sampling Frequency ◽  
Variable Gain Amplifier ◽  
Effective Number ◽  
Worst Case ◽  
Flash Adc ◽  
Variable Gain

This paper presents design of a sampler circuit for folding flash ADC. There is a desire for Low power high performance ADC for communication. For low power the size of the ADC should be minimized and for the fast performance flash can be used. Hence to reduce the number of transistors in flash ADC folding network is proposed here. Sampling is the important technique used in the ADC part. In this discussion the sampler circuit includes a differential track and hold switch followed by a variable gain amplifier with a gain of 1 db, a buffer and a folding network. An input voltage of1 V and the sampling frequency of 1GS/s is applied to the sampler circuit. Effective number of bits of more than 5.7 bits is achieved also THD is below -35db in VGA. Buffer achieves a ENOB of 10bits with THD less than -65db. This sampler circuit is designed with the technology of 45nm for coherent sampling. Worst case SNDR is calculated.

A High Efficiency Variable Gain Amplifier Circuit with Controllable Transconductance Amp

2009 ◽  
Vol 129 (10) ◽  
pp. 1968-1969
Author(s):  
Tetsuro Okura ◽  
Shunsuke Okura ◽  
Toru Ido ◽  
Kenji Taniguchi
Keyword(s):  
High Efficiency ◽  
Variable Gain Amplifier ◽  
Amplifier Circuit ◽  
Variable Gain

A Fully Differential Variable Gain Amplifier for Portable Impedance Sensing Applications

2019 ◽  
Vol 7 ◽  
Author(s):  
Jorge Pérez Bailón ◽  
Jaime Ramírez-Angulo ◽  
Belén Calvo ◽  
Nicolás Medrano
Keyword(s):  
Power Consumption ◽  
Active Area ◽  
Variable Gain Amplifier ◽  
Cmos Process ◽  
Current Steering ◽  
Impedance Sensing ◽  
Variable Gain ◽  
Fully Differential ◽  
Sensing Applications ◽  
Constant Bandwidth

This paper presents a Variable Gain Amplifier (VGA) designed in a 0.18 μm CMOS process to operate in an impedance sensing interface. Based on a transconductance-transimpedance (TC-TI) approach with intermediate analog-controlled current steering, it exhibits a gain ranging from 5 dB to 38 dB with a constant bandwidth around 318 kHz, a power consumption of 15.5 μW at a 1.8 V supply and an active area of 0.021 mm2.

scholarly journals An E-Band 21-dB Variable-Gain Amplifier with 0.5-V Supply in 40-nm CMOS

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 804
Author(s):  
Gibeom Shin ◽  
Kyunghwan Kim ◽  
Kangseop Lee ◽  
Hyun-Hak Jeong ◽  
Ho-Jin Song
Keyword(s):  
Power Consumption ◽  
Frequency Band ◽  
Noise Figure ◽  
Complementary Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Operating Frequency ◽  
Variable Gain Amplifier ◽  
Variable Gain ◽  
Operating Frequency Band ◽  
Shunt Capacitors

This paper presents a variable-gain amplifier (VGA) in the 68–78 GHz range. To reduce DC power consumption, the drain voltage was set to 0.5 V with competitive performance in the gain and the noise figure. High-Q shunt capacitors were employed at the gate terminal of the core transistors to move input matching points for easy matching with a compact transformer. The four stages amplifier fabricated in 40-nm bulk complementary metal oxide semiconductor (CMOS) showed a peak gain of 24.5 dB at 71.3 GHz and 3‑dB bandwidth of more than 10 GHz in 68–78 GHz range with approximately 4.8-mW power consumption per stage. Gate-bias control of the second stage in which feedback capacitances were neutralized with cross-coupled capacitors allowed us to vary the gain by around 21 dB in the operating frequency band. The noise figure was estimated to be better than 5.9 dB in the operating frequency band from the full electromagnetic (EM) simulation.

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