scholarly journals A Two-Module Linear Regulator with 3.9–10 V Input, 2.5 V Output, and 500 mA Load

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1143
Author(s):  
Quanzhen Duan ◽  
Weidong Li ◽  
Shengming Huang ◽  
Yuemin Ding ◽  
Zhen Meng ◽  
...  

A linear regulator with an input range of 3.9–10 V, 2.5 V output, and a maximal 500 mA load for use with battery systems was developed and presented here. The linear regulator featured two modules of a preregulator and a linear regulator core circuit, offering minimized power dissipation and high-level stability. The preregulator delivered an internal power voltage of 3 V and supplied internal circuits including the second module (the linear regulator core). The preregulator fitted with an active, low-pass filter provided a low-noise reference voltage to the linear regulator core circuit. To ensure operational stability for the linear regulator, error amplifiers incorporating the Miller compensation technique and featuring a large slewing rate were employed in the two modules. The circuit was successfully implemented in a 0.25 µm, 5 V complementary metal-oxide semiconductor (CMOS) process featuring 20 V drain-extended MOS (DMOS)/bipolar high-voltage devices. The total silicon area, including all pads, was approximately 1.67 mm2. To reduce chip area, bipolar rather than DMOS transistors served as the power transistors. Measured results demonstrated that the designed linear regulator was able to operate at an input voltage ranging from 3.9 to 10 V and offer a maximum 500 mA load current with fixed 2.5 V output voltage.

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2065 ◽  
Author(s):  
Jinyong Zhang ◽  
Shing-Chow Chan ◽  
Hui Li ◽  
Nannan Zhang ◽  
Lei Wang

This paper proposes a compact, high-linearity, and reconfigurable continuous-time filter with a wide frequency-tuning capability for biopotential conditioning. It uses an active filter topology and a new operational-transconductance-amplifier (OTA)-based current-steering (CS) integrator. Consequently, a large time constant τ , good linearity, and linear bandwidth tuning could be achieved in the presented filter with a small silicon area. The proposed filter has a reconfigurable structure that can be operated as a low-pass filter (LPF) or a notch filter (NF) for different purposes. Based on the novel topology, the filter can be readily implemented monolithically and a prototype circuit was fabricated in the 0.18 μm standard complementary-metal–oxide–semiconductor (CMOS) process. It occupied a small area of 0.068 mm2 and consumed 25 μW from a 1.8 V supply. Measurement results show that the cutoff frequency of the LPF could be linearly tuned from 0.05 Hz to 300 Hz and the total-harmonic-distortion (THD) was less than −76 dB for a 2 Hz, 200 mVpp sine input. The input-referred noises were 5.5 μVrms and 6.4 μVrms for the LPF and NF, respectively. A comparison with conventional designs reveals that the proposed design achieved the lowest harmonic distortion and smallest on-chip capacitor. Moreover, its ultra-low cutoff frequency and relatively linear frequency tuning capability make it an attractive solution as an analog front-end for biopotential acquisitions.


2020 ◽  
Vol 10 (1) ◽  
pp. 348 ◽  
Author(s):  
Donggeun You ◽  
Hyungseup Kim ◽  
Jaesung Kim ◽  
Kwonsang Han ◽  
Hyunwoo Heo ◽  
...  

This paper presents a low-noise reconfigurable sensor readout circuit with a multimodal sensing chain for voltage/current/resistive/capacitive microsensors such that it can interface with a voltage, current, resistive, or capacitive microsensor, and can be reconfigured for a specific sensor application. The multimodal sensor readout circuit consists of a reconfigurable amplifier, programmable gain amplifier (PGA), low-pass filter (LPF), and analog-to-digital converter (ADC). A chopper stabilization technique was implemented in a multi-path operational amplifier to mitigate 1/f noise and offsets. The 1/f noise and offsets were up-converted by a chopper circuit and caused an output ripple. An AC-coupled ripple rejection loop (RRL) was implemented to reduce the output ripple caused by the chopper. When the amplifier was operated in the discrete-time mode, for example, the capacitive-sensing mode, a correlated double sampling (CDS) scheme reduced the low-frequency noise. The readout circuit was designed to use the 0.18-µm complementary metal-oxide-semiconductor (CMOS) process with an active area of 9.61 mm2. The total power consumption was 2.552 mW with a 1.8-V supply voltage. The measured input referred noise in the voltage-sensing mode was 5.25 µVrms from 1 Hz to 200 Hz.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4694
Author(s):  
Kyeongsik Nam ◽  
Hyungseup Kim ◽  
Yongsu Kwon ◽  
Gyuri Choi ◽  
Taeyup Kim ◽  
...  

Air flow measurements provide significant information required for understanding the characteristics of insect movement. This study proposes a four-channel low-noise readout integrated circuit (IC) in order to measure air flow (air velocity), which can be beneficial to insect biomimetic robot systems that have been studied recently. Instrumentation amplifiers (IAs) with low-noise characteristics in readout ICs are essential because the air flow of an insect’s movement, which is electrically converted using a microelectromechanical systems (MEMS) sensor, generally produces a small signal. The fundamental architecture employed in the readout IC is a three op amp IA, and it accomplishes low-noise characteristics by chopping. Moreover, the readout IC has a four-channel input structure and implements an automatic offset calibration loop (AOCL) for input offset correction. The AOCL based on the binary search logic adjusts the output offset by controlling the input voltage bias generated by the R-2R digital-to-analog converter (DAC). The electrically converted air flow signal is amplified using a three op amp IA, which is passed through a low-pass filter (LPF) for ripple rejection that is generated by chopping, and converted to a digital code by a 12-bit successive approximation register (SAR) analog-to-digital converter (ADC). Furthermore, the readout IC contains a low-dropout (LDO) regulator that enables the supply voltage to drive digital circuits, and a serial peripheral interface (SPI) for digital communication. The readout IC is designed with a 0.18 μm CMOS process and the current consumption is 1.886 mA at 3.3 V supply voltage. The IC has an active area of 6.78 mm2 and input-referred noise (IRN) characteristics of 95.4 nV/√Hz at 1 Hz.


2019 ◽  
Vol 82 (1) ◽  
Author(s):  
Florence Choong ◽  
Mamun Ibne Reaz ◽  
Mohamad Ibrahim Kamaruzzaman ◽  
Md. Torikul Islam Badal ◽  
Araf Farayez ◽  
...  

Digital controlled oscillator (DCO) is becoming an attractive replacement over the voltage control oscillator (VCO) with the advances of digital intensive research on all-digital phase locked-loop (ADPLL) in complementary metal-oxide semiconductor (CMOS) process technology. This paper presents a review of various CMOS DCO schemes implemented in ADPLL and relationship between the DCO parameters with ADPLL performance. The DCO architecture evaluated through its power consumption, speed, chip area, frequency range, supply voltage, portability and resolution. It can be concluded that even though there are various schemes of DCO that have been implemented for ADPLL, the selection of the DCO is frequently based on the ADPLL applications and the complexity of the scheme. The demand for the low power dissipation and high resolution DCO in CMOS technology shall remain a challenging and active area of research for years to come. Thus, this review shall work as a guideline for the researchers who wish to work on all digital PLL.


2013 ◽  
Vol 27 (26) ◽  
pp. 1350159
Author(s):  
HYUNJUNE LYU ◽  
JUN RIM CHOI

For the purpose of biomagnetic measurements, a magnetic sensor chip is manufactured using a 0.18 μm complementary metal–oxide–semiconductor (CMOS) process. A high-inductance coil and an instrumentation amplifier (IA) are embedded on this chip. The embedded high-inductance coil sensor contains suitable sensitivity and bandwidth for biomagnetic measurements, and is designed via electromagnetic field simulation. A low-gm operational transconductance amplifier (OTA) is also implemented on the chip to reduce the transconductance value. The output signal sensitivity of the magnetic sensor chip is 3.25 fT/μV, and the output reference noise is [Formula: see text]. The instrumentation amplifier is designed to minimize the magnetic signal noise using current feedback and a band-pass filter (BPF) with a bandwidth between 0.5 kHz and 5 kHz. The common-mode rejection ratio (CMRR) is measured at 117.5 dB by the Multi-Project Chip test. The proposed magnetic sensor chip is designed such that the input reference noise is maintained below 0.87 μV.


2015 ◽  
Vol 645-646 ◽  
pp. 1279-1284
Author(s):  
Zhang Zhang ◽  
Zheng Xi Cheng ◽  
Yi Wei Zhuang

A low power low noise CMOS amplifier with integrated filter for neural signal recording is designed and fabricated with CSMC 0.5 μm CMOS process. DC offsets introduced by electrode-tissue interface are rejected through a feedback low-pass filter. The bandwidth of the amplifier is in 3.5Hz-5.5KHz range, and the gain is about 48dB in the midband. AC input differential mode voltage range is 10mV, and DC input differential mode voltage range is 180mV. The amplifier can accommodate 180mV DC offsets drift and 10mV neural spikes. The neural probe array is integrated directly on the surface of the amplifier array chip, and is tested in saline solution, and also is implanted in rats in vivo , the results of the experiments show that the amplifier is suitable for neural signal recording. The power dissipation is about 14μW while consuming 0.16 mm2 of chip area, which satisfies implantable devices requirements.


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.


2020 ◽  
Vol 34 (29) ◽  
pp. 2050321
Author(s):  
Wei Wang ◽  
Hong-An Zeng ◽  
Fang Wang ◽  
Guanyu Wang ◽  
Yingtao Xie ◽  
...  

A new avalanche photodiode device applied to a visible light communication (VLC) system is designed using a standard 0.18 [Formula: see text]m complementary metal oxide semiconductor process. Compared to regular CMOS APD devices, the proposed device adds a [Formula: see text]-well layer above the deep [Formula: see text]-well/[Formula: see text]-substrate structure, and an [Formula: see text]/[Formula: see text] layer is deposited upon it. The [Formula: see text]/[Formula: see text] layer acts as an avalanche breakdown layer of the device, and an STI structure is used to prevent the edge break prematurely. The simulation results shows that the avalanche breakdown voltage is as low as 9.9 V, dark current is below [Formula: see text] A under −9.5 V bias voltage, and the 3 dB bandwidth is of 5.9 GHz. It is due to the use of the 0.18 [Formula: see text]m CMOS process-specific STI protection ring and short-circuits the connection of the deep [Formula: see text]-well/[Formula: see text]-substrate, and the dark current is reduced to be lower than two orders of magnitude compared to regular CMOS APD. Gain and noise characteristics are accurately calculated from Hayat dead-space model applied to this CMOS APD. So, this device’s gain and excess noise factor are 20 and 2.5, respectively.


2013 ◽  
Vol 22 (06) ◽  
pp. 1350044 ◽  
Author(s):  
MOHAMMAD HOSSEIN MAGHAMI ◽  
AMIR M. SODAGAR

A new simple dual-output second generation current conveyor (DO-CCII) circuit is proposed. Designed in a standard 0.5-μm CMOS process, the circuit operates at ±1.5 V supply voltages with a total power consumption of 106 nW. Main characteristics of the proposed DO-CCII are its simplicity, small silicon area consumption, and not suffering from the body effect of MOS transistors. The proposed circuit is employed to implement a first-order low-pass filter with upper -3 dB cut-off frequency of as low as 3.2 Hz.


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