scholarly journals A Low Quiescent Current Fast Settling Capacitor-less Low Drop Out Regulator Employing Multiple Loops

Author(s):  
Suresh Alapati ◽  
Patri Sreehari Rao

<p>This paper presents a fast transient and low noise capacitor-less LDO using multiple loops. The proposed LDO exploits adaptive biasing, bulk modulation and a fast reacting control loop for achieving high performance striking reasonable tradeoffs among quiescent current, transient response and stability. The proposed LDO offers a load regulation of 0.095µV/mA while consuming quiescent current of 16 µA. It exhibits a load transient of 134.23mV with a settling time of 240.8ns against 0 to 100mA load variation with 40pF output capacitor. It exhibits an integrated noise of 31.027 pV2 /Hz at 10 Hz for a maximum load current of 100mA. The proposed LDO is designed using 0.18-µm 1P6 CMOS process.</p>

2011 ◽  
Vol 20 (01) ◽  
pp. 1-13 ◽  
Author(s):  
CHENCHANG ZHAN ◽  
WING-HUNG KI

A CMOS low quiescent current low dropout regulator (LDR) with high power supply rejection (PSR) and without large output capacitor is proposed for system-on-chip (SoC) power management applications. By cascoding a power NMOS with the PMOS pass transistor, high PSR over a wide frequency range is achieved. The gate-drive of the cascode NMOS is controlled by an auxiliary LDR that draws only 1 μA from a small charge pump, thus helping in reducing the quiescent current. Adaptive biasing is employed for the multi-stage error amplifier of the core LDR to achieve high loop gain hence high PSR at low frequency, low quiescent current at light load and high bandwidth at heavy load. A prototype of the proposed high-PSR LDR is fabricated using a standard 0.35 μm CMOS process, occupying an active area of 0.066 mm2. The lowest supply voltage is 1.6 V and the preset output voltage is 1.2 V. The maximum load current is 10 mA. The measured worst-case PSR at full load without using large output capacitor is -22.7 dB up to 60 MHz. The line and load regulations are 0.25 mV/V and 0.32 mV/mA, respectively.


2015 ◽  
Vol 24 (06) ◽  
pp. 1550078 ◽  
Author(s):  
Seid Jafar Hosseinipouya ◽  
Farhad Dastadast

High performance of fully differential operational transconductance amplifier is designed and implemented using a 0.18-μm CMOS process. The implemented op-amp uses common mode feedback (CMFB) circuit operating in weak inversion region which does not affect other electrical characteristics due to eliminating common mode (CM) levels automatically leading to improve CM rejection ratio (CMRR) of the amplifier significantly. Moreover, the output stage has class-AB operation so that its current can be made larger due to increasing the output current dynamically using adaptive biasing circuit. Additionally, the AC currents of the active loads have been significantly reduced using negative impedances to increase the gain of the amplifier. The results show the GBW 2.3 MHz, slew rate 2.6 V/μs and 1% settling time 150 ns with a capacitive load of 15 pF. This amplifier dissipates only 6.2 μW from a 1.2 V power supply.


2011 ◽  
Vol 483 ◽  
pp. 471-474
Author(s):  
Wei Ping Chen ◽  
Qing Yi Wang ◽  
Liang Yin ◽  
Zhi Ping Zhou

In this work, an ASIC interface for quartz rate sensor (QRS) is introduced. Based on 0.6μm 18V N-well CMOS process, it is the first to be realized in the domestic. This chip has a minimized size of 5×4.4mm2. Compared with traditional interface constructed by separate devices, such interface implemented with integrated circuits is advantageous in size and power consumption. This satisfies the requirements of miniature and low power consumption in space industry and military domain. The test results show that this interface features low noise, high linearity, and stable operation. Integrated with the sensor, the entire system presents high performance in short term bias stability, nonlinearity, output noise, bias variation over temperature, and power consumption.


Author(s):  
Mohamad Khairul bin Mohd Kamel ◽  
Yan Chiew Wong

Harvesting energy from ambient Radio Frequency (RF) source is a great deal toward batteryless Internet of Thing (IoT) System on Chip (SoC) application as green technology has become a future interest. However, the harvested energy is unregulated thus it is highly susceptible to noise and cannot be used efficiently. Therefore, a dedicated low noise and high Power Supply Ripple Rejection (PSRR) of Low Dropout (LDO) voltage regulator are needed in the later stages of system development to supply the desired load voltage. Detailed analysis of the noise and PSRR of an LDO is not sufficient. This work presents a design of LDO to generate a regulated output voltage of 1.8V from 3.3V input supply targeted for 120mA load application. The performance of LDO is evaluated and analyzed. The PSRR and noise in LDO have been investigated by applying a low-pass filter. The proposed design achieves the design specification through the simulation results by obtaining 90.85dB of open-loop gain, 76.39º of phase margin and 63.46dB of PSRR respectively. The post-layout simulation shows degradation of gain and maximum load current due to parasitic issue. The measurement of maximum load regulation is dropped to 96mA compared 140mA from post-layout. The proposed LDO is designed using 180nm Silterra CMOS process technology.


2019 ◽  
Vol 8 (1) ◽  
pp. 65-73
Author(s):  
Chu-Liang Lee ◽  
Roslina Mohd Sidek ◽  
Nasri Sulaiman ◽  
Fakhrul Zaman Rokhani

This paper proposed a low quiescent current low-dropout voltage regulator (LDO) with self-compensation loop stability. This LDO is designed for Silicon-on-Chip (SoC) application without off-chip compensation capacitor. Worst case loop stability phenomenon happen when LDO output load current (Iload) is zero. The second pole frequency decreased tremendously towards unity-gain frequency (UGF) and compromise loop stability. To prevent this, additional current is needed to keep the output in low impedance in order to maintain second pole frequency. As Iload slowly increases, the unneeded additional current can be further reduced. This paper presents a circuit which performed self-reduction on this current by sensing the Iload. On top of that, a self-compensation circuit technique is proposed where loop stability is selfattained when Iload reduced below 100μA. In this technique, unity-gain frequency (UGF) will be decreaed and move away from second pole in order to attain loop stability. The decreased of UGF is done by reducing the total gain while maintaining the dominant pole frequency. This technique has also further reduced the total quiescent current and improved the LDO’s efficiency. The proposed LDO exhibits low quiescent current 9.4μA and 17.7μA, at Iload zero and full load 100mA respectively. The supply voltage for this LDO is 1.2V with 200mV drop-out voltage. The design is validated using 0.13μm CMOS process technology.


2013 ◽  
Vol 22 (09) ◽  
pp. 1340015 ◽  
Author(s):  
YAJING ZHANG ◽  
WENGAO LU ◽  
GUANNAN WANG ◽  
ZHONGJIAN CHEN ◽  
YACONG ZHANG

A readout integrated circuit (ROIC) of infrared focal plane array (IRFPA) with low power and low noise is presented in this paper. It consists of a 384 × 288 pixel array and column-level A/D conversion circuits. The proposed system has high resolution because of the odd–even Analog to Digital Conversion (ADC) structure, containing correlated switches design, multi-Vth amplifier design and high speed high resolution comparator design including latch-stage. Designed and simulated in 0.35-μm CMOS process, this high performance ROIC achieves 81.24 dB SNR at 8.64 KS/s consuming 98 mW under 5 V voltage supply, resulting in an ENOB of 13.2-bit.


2019 ◽  
Vol 15 (2) ◽  
pp. 113-118
Author(s):  
Agata Romanova ◽  
Vaidotas Barzdenas

AbstractThe work reports on the design and performance of a low-noise low-cost CMOS transimpedance amplifier (TIA). The proposed circuit shall be employed in optical time-domain reflectometers and is implemented using an affordable 0.18 µm 1.8 V CMOS process. The approach preserves the benefits of a classical feedback structure while addressing the noise problem of conventional feed-forward and resistive feedback architectures via the usage of noise-efficient capacitive feedback. Circuit-level modifications are proposed to mitigate the voltage headroom and DC current issues. The suggested design achieves a total gain of 82 dBΩ (79 dBΩ after the output buffer) within the bandwidth of 1.2 GHz while operating with a total input capacitance of 0.7 pF. The simulated average input-referred noise current density is below 1.8 pA/sqrt(Hz) with the power consumption of the complete amplifier including the output buffer being 21 mW.


The present world is ruled by wireless communication. From a telephone communication to satellite communication, the word “wireless” plays a major rule. In the recent years, the modem wireless communication in broadcast and microwave radio demands the properly designed Low Noise Amplifier (LNA) in receiver front ends for proper communication. The paper presents the design of high performance low noise amplifier at radio frequency regime. The LNA is implemented at operating frequency of 1.6 GHz and 2.6 GHz has been implemented at .18um CMOS process. LNA are regularly used in wireless communication receiver leading-ends due to their equity to intensify shaky Radio Frequency (RF) signals without summing additional noise. Cadence virtuoso tool has been used to implement the LNA design and the performance parameters are analyzed at operating frequency.


Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2309
Author(s):  
Hyoung-Rae Kim ◽  
Chang-Ho An ◽  
Bai-Sun Kong

A high-speed column driver IC with an area-efficient high-slew-rate buffer amplifier is proposed for use in a large-sized, high-resolution TFT-LCD panel application. In the proposed architecture, explicit isolation switches have been embedded into the buffer amplifier resulting in a fast settling response. The amplifier also has a structure that adjusts the tail current of the input stage using a very compact adaptive biasing. The proposed column driver IC, having the proposed buffer amplifier for driving a 55-inch 4K ultra-high-definition (UHD) TV panel, was fabricated in a 0.18-μm 1.8-V low-voltage, 1.2-μm 9-V medium-voltage, and 1.6-μm 18-V high-voltage CMOS process. The performance evaluation results indicated that 90% and 99.9% falling settling times were improved from 1.947 µs to 0.710 µs (63.5% improvement) and 4.131 µs to 2.406 µs (41.7% improvement), respectively. They also indicated that the layout size of the proposed buffer amplifier was reduced from 5580 μm2 to 4402 μm2 (21.1% reduction).


Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1382
Author(s):  
Xiaoying Deng ◽  
Huazhang Li ◽  
Mingcheng Zhu

Based on the idea of bisection method, a new structure of All-Digital Phased-Locked Loop (ADPLL) with fast-locking is proposed. The structure and locking method are different from the traditional ADPLLs. The Control Circuit consists of frequency compare module, mode-adjust module and control module, which is responsible for adjusting the frequency control word of digital-controlled-oscillator (DCO) by Bisection method according to the result of the frequency compare between reference clock and restructure clock. With a high frequency cascade structure, the DCO achieves wide tuning range and high resolution. The proposed ADPLL was designed in SMIC 180 nm CMOS process. The measured results show a lock range of 640-to-1920 MHz with a 40 MHz reference frequency. The ADPLL core occupies 0.04 mm2, and the power consumption is 29.48 mW, with a 1.8 V supply. The longest locking time is 23 reference cycles, 575 ns, at 1.92 GHz. When the ADPLL operates at 1.28 GHz–1.6 GHz, the locking time is the shortest, only 9 reference cycles, 225 ns. Compared with the recent high-performance ADPLLs, our design shows advantages of small area, short locking time, and wide tuning range.


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