A differential inverter-based switched-capacitor oscillator in 65 nm CMOS technology

2015 ◽  
Author(s):  
Peng Wang ◽  
Gyorgy Csaba ◽  
Wolfgang Porod ◽  
Trond Ytterdal
Keyword(s):  
Cmos Technology ◽  
Switched Capacitor

A New Sub-1 Volt 17ppm/°C Offset-Insensitive Resistorless Switched-Capacitor Bandgap Voltage Reference

2020 ◽  
pp. 2150029
Author(s):  
Emad Ebrahimi ◽  
Maliheh Arabnasery
Keyword(s):  
Process Variations ◽  
Voltage Divider ◽  
Cmos Technology ◽  
Reference Voltage ◽  
Cmos Process ◽  
Switched Capacitor ◽  
Voltage Reference ◽  
Op Amp ◽  
Offset Voltage ◽  
Bandgap Voltage Reference

A new PVT compensated voltage reference is presented by using switched-capacitor (S.C.) technique. In the proposed bandgap voltage reference (BGR), a p–n junction is biased with different currents during two different phases and required PTAT and CTAT voltages generated and held by two capacitors. Using a capacitive voltage divider, the PTAT voltage is weighted such that the sub-1V bandgap voltage is achievable. In order to cancel the effect of op-amp offset and to relax the design of op-amp, the offset voltage of the op-amp is sampled by a capacitor during a specified phase and inversely is added to the final bandgap voltage in next phase. The analysis of the proposed S.C. BGR is supplemented by simulation of a 0.5-V BGR with 28[Formula: see text][Formula: see text][Formula: see text]W power consumption in a standard 0.18[Formula: see text][Formula: see text][Formula: see text]m CMOS technology. Simulation results show that the average temperature coefficient of the S.C. BGR is 17[Formula: see text]ppm/∘C and it is robust against the process variations. Applying an arbitrary 100-mV op-amp offset results in a lower than 1.1[Formula: see text]mV deviation in generated reference voltage. Due to the better matching of MIM capacitors in CMOS process (rather than resistors used in conventional BGR) the proposed S.C. bandgap provides good accuracy without any post trimming. Monte–Carlo analysis shows that [Formula: see text]/[Formula: see text] of the generated reference voltage is as low as 0.7%. The sensitivity of the proposed BGR to supply variation is also less than 1%/V.

The Design of CIFF Structure Three-Order Switched-Capacitor Sigma-Delta Modulator

2012 ◽  
Vol 433-440 ◽  
pp. 5727-5732
Author(s):  
Jun Han ◽  
Wei Dong Wang
Keyword(s):  
Dynamic Range ◽  
Supply Voltage ◽  
Optimization Technique ◽  
Cmos Technology ◽  
Switched Capacitor ◽  
Clock Frequency ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Transconductance Amplifier ◽  
A Chain

This paper presents the design and implementation of a single-loop three-order switched-capacitor sigma-delta modulator(SDM) with a standard 0.18um CMOS technology. A current optimization technique is utilized in proposed design to reduce the power of operational transconductance amplifier(OTA).Using a chain of Integrators with weighted feed-forward summation(CIFF) structure and optimized single-stage class-A OTA with positive feed-back to minimize the power consumption. The SDM has been presented with an over-sampling ratio of 128,clock frequency 6.144MHz,24kHz band- width, and achieves a peak SNR of 100dB,103dB dynamic range. The whole circuits consume 2.87mW from a single 1.8V supply voltage.

A RE-CONFIGURABLE ARCHITECTURE FOR SWITCHED CAPACITOR SIGMA-DELTA ANALOG-TO-DIGITAL CONVERSION

2013 ◽  
Vol 22 (09) ◽  
pp. 1340012
Author(s):  
KAREN WAN ◽  
GIGI CHAN ◽  
WILLIAM WONG ◽  
KAM CHUEN WAN ◽  
BRYCE YAU ◽  
...  
Keyword(s):  
Fourth Order ◽  
Cmos Technology ◽  
Second Order ◽  
Switched Capacitor ◽  
Noise Shaping ◽  
Digital Conversion ◽  
Sigma Delta Modulator ◽  
Sigma Delta ◽  
Analog To Digital ◽  
Analog To Digital Conversion

A re-configurable switched capacitor sigma-delta analog-to-digital conversion architecture1,2 is proposed. The architecture consists of a MASH sigma delta modulator with nth lower-order (first- or second-order) loops cascaded together. Each loop can be powered on or off operating in high or low performance mode, according to application needs. The architecture can be configured to optimize performance and power consumption for specific resolution and applications. The architecture is proven by means of a prototype, implemented as a fourth-order and fabricated in a standard 0.18 um CMOS technology. The outputs of both high performance mode (fourth-order) and medium performance mode (second-order, first loop ON) are measured to demonstrate the configurability. The FFT demonstrates that the noise shaping for the fourth-order modulator is better than that of the second-order modulator with steeper noise shaping slope.

scholarly journals A High-Dynamic-Range Switched-Capacitor Sigma-Delta ADC for Digital Micromechanical Vibration Gyroscopes

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 372 ◽  
Author(s):  
Risheng Lv ◽  
Weiping Chen ◽  
Xiaowei Liu
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
High Dynamic Range ◽  
Cmos Technology ◽  
Noise Cancellation ◽  
Switched Capacitor ◽  
Noise Shaping ◽  
Sigma Delta ◽  
Multi Stage ◽  
Sigma Delta Adc

This paper presents a multi-stage noise shaping (MASH) switched-capacitor (SC) sigma-delta (ΣΔ) analog-to-digital converter (ADC) composed of an analog modulator with an on-chip noise cancellation logic and a reconfigurable digital decimator for MEMS digital gyroscope applications. A MASH 2-1-1 structure is employed to guarantee an absolutely stable modulation system. Based on the over-sampling and noise-shaping techniques, the core modulator architecture is a cascade of three single-loop stages containing feedback paths for systematic optimization to avoid deterioration in conversion accuracy caused by capacitor mismatch. A digital noise cancellation logic is also included to eliminate residual quantization errors in the former two stages, and those in the last stage are shaped by a fourth-order modulation. A multi-rate decimator follows the analog modulator to suit variable gyroscope bandwidth. Manufactured in a standard 0.35 μm CMOS technology, the whole chip occupies an area of 3.8 mm2. Experimental results show a maximum signal-to-noise ratio (SNR) of 100.2 dB and an overall dynamic range (DR) of 107.6 dB, with a power consumption of 3.2 mW from a 5 V supply. This corresponds to a state-of-the-art figure-of-merit (FoM) of 165.6 dB.

A Compact High-Performance 10-bit 30-Channel OLED Driver Using Switched Capacitor Circuit for High-Linearity Application

2021 ◽  
pp. 2250013
Author(s):  
Neeru Agarwal ◽  
Neeraj Agarwal ◽  
Chih-Wen Lu
Keyword(s):  
Power Consumption ◽  
Output Voltage ◽  
High Speed ◽  
High Performance ◽  
Input Voltage ◽  
Cmos Technology ◽  
Settling Time ◽  
Switched Capacitor ◽  
Voltage Range ◽  
High Output Voltage

This work proposes a new OLED driver architecture with 10-bit segmented DAC and switched capacitor multiply-by-two circuit application. A 30-channel 10-bit switched capacitor driver chip prototype is implemented in 0.18-[Formula: see text]m CMOS technology. In this architecture, the achieved output range is 1.5–4.8[Formula: see text]V for an input range of 1.5–3.15[Formula: see text]V, which is suitable for OLED driver with different colors. This architecture is not only converting the digital input signal to analog output for the display panel but also giving amplified high output voltage range. In the segmented DAC, 6-bit coarse DAC and 4-bit fine DAC are used for the input voltage range 1.5–3.15[Formula: see text]V. In a conventional RDAC for the output voltage of 4.8[Formula: see text]V, it requires 2[Formula: see text] switches i.e., 14-bit RDAC for the same resolution. Hence, conventional RDAC driver is four times larger than the proposed innovative very compact and high speed 10-bit segmented DAC switched capacitor OLED driver. The new architecture drastically reduces the number of switches and complex metal routing which results in reduced power consumption and good settling time. In the proposed OLED driver, no extra buffer is required as switched capacitor op-amp is applied for the same purpose with a gain of more than one. This high-resolution design with small die area also improves the linearity and uniformity with low-power consumption. The post-simulated results show that the OLED driver exhibits the maximum DNL and INL of 0.03 LSB and [Formula: see text]0.06 LSB, respectively, with an LSB voltage of 3[Formula: see text]mV. The one-channel area is 0.586[Formula: see text]mm [Formula: see text] 0.017[Formula: see text]mm and the settling time is 4.25[Formula: see text][Formula: see text]s for 30[Formula: see text]k[Formula: see text] and 30[Formula: see text]pF driving load.

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