Design of a Programmable Gain, Temperature Compensated Current-Input Current-Output CMOS Logarithmic Amplifier

We present in this paper a fully integrated low-noise high common-mode rejection ratio (CMRR) logarithmic programmable gain amplifier (LPGA) and chopped LPGA circuits for EEG acquisition systems. The proposed LPGA is based on a rail-to-rail true logarithmic amplifier (TLA) stage. The high CMRR achieved in this work is a result of cascading three amplification stages to construct the LPGA in addition to the lower common-mode gain of the proposed logarithmic amplification topology. In addition, the 1 / f noise and the inherent DC offset voltage of the input transistors are reduced using a chopper stabilization technique. The CMOS 180 nm standard technology is used to implement the circuits. Experimental results for the integrated LPGA show a CMRR of 140 dB, a differential gain of 37 dB, an input-referred noise of 0.754 μ Vrms, a 189 μ W power consumption from 1.8 V power supply and occupies an active area of 0.4 mm 2 .

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Multi-Function Active-Only High-Order Current-Driven Filter

Active and Passive Electronic Components ◽

10.1155/apec.23.157 ◽

2000 ◽

Vol 23 (3) ◽

pp. 157-161

Author(s):

Muhammad Taher Abuelma'atti ◽

Husain Abdullah Alzaher

Keyword(s):

Output Voltage ◽

High Order ◽

Input Current ◽

Operational Amplifiers ◽

Output Current ◽

Current Output ◽

Circuit Topology ◽

Operational Transconductance Amplifiers ◽

Order Filter ◽

Transconductance Amplifiers

A new multi-function high-order current-driven filter is proposed. The filter uses only operational amplifiers, and operational transconductance amplifiers (OTAs). Without using any external passive elements, a variety of high-order input-current/output-current and/or input-current/output-voltage responses can be realised without changing the circuit topology and without any matching or cancellation conditions. The parameters of the high-order filter responses can be electronically tuned by adjusting the bias currents of the OTAs.

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Programmable Gain, Temperature Compensated Logarithmic Amplifier based on Current Conveyor and OTA

2018 International Conference on Computing and Network Communications (CoCoNet) ◽

10.1109/coconet.2018.8476890 ◽

2018 ◽

Cited By ~ 1

Author(s):

Dmitriy Kupreyev ◽

Kassen Dautov ◽

Mohammad Hashmi

Keyword(s):

Current Conveyor ◽

Logarithmic Amplifier ◽

Programmable Gain

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Cascadable and Tunable Analog Building Blocks Using EX-CCCII

Journal of Circuits System and Computers ◽

10.1142/s0218126617500931 ◽

2017 ◽

Vol 26 (06) ◽

pp. 1750093 ◽

Cited By ~ 12

Author(s):

Sudhanshu Maheshwari ◽

Deepak Agrawal

Keyword(s):

Supply Voltage ◽

Building Blocks ◽

Second Order ◽

Input Current ◽

Pass Filter ◽

Current Output ◽

First Order ◽

Component Matching ◽

Electronically Tunable ◽

Matching Constraints

A new cascadable voltage-input, current-output first-order all-pass filter and its applications in second-order filter and oscillator are presented. The proposed circuit employs a single active element namely extra-X current-controlled current conveyor (EX-CCCII) and only a single grounded capacitor. The circuit exhibits high input and high output impedances, so that the filter can be cascaded without additional buffers. The pole frequency is electronically tunable and the circuit requires no component matching constraints. Effects of nonidealities and parasitics are also discussed. As applications, a second-order transadmittance (TA)-mode all-pass filter and a quadrature oscillator are also realized using the proposed voltage-input, current-output first-order all-pass filter. These examples validate easy cascading feature of the proposed circuit. The validity of the proposed circuit is verified through PSPICE simulations using 0.25[Formula: see text][Formula: see text]m parameters with a supply voltage of [Formula: see text][Formula: see text]V.

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