Conventional techniques to achieve a constant-gm rail-to-rail complementary N-P differential input stage require complex additional circuitry. In addition, the frequency response and common-mode rejection ratio (CMRR) are degraded. An economical but efficient design technique to overcome these problems is proposed. The proposed technique strategically overlaps the transition regions of the tail...

A novel topology for a high gain two-stage amplifier is proposed. The proposed circuit is designed in a way that the non-dominant pole is at output of the first stage. A positive capacitive feedback (PCF) around the second stage introduces a left half plane (LHP) zero which cancels the phase shift introduced by the non-dominant pole, considerably. The dominant pole is at the output node which m...

This paper describes the development of a low-power electrocardiogram (ECG) touch sensor intended for the use with two dry metal electrodes. An equivalent ECG extraction circuit model encountered in a ground-free two-electrode configuration is investigated for an optimal sensor read-out circuit design criteria. From the equivalent circuit model, (1) maximum sensor resolution is derived based on...

The preamplifier block is crucial in bio-medical signal processing. The power intensive Operational Transconductance Amplifier (OTA) is considered, and the performance of preamplifier is studied. A low noise and low power telescopic OTA is proposed in this work. To reduce the noise contribution in the active load transistors, source degeneration technique is incorporated in the current stealing...

A biopotential amplifier for single supply operation is presented. It uses a Driven Right Leg Circuit (DRL) to drive the patient's body to a DC common mode voltage, centering biopotential signals with respect to the amplifier's input voltage range. This scheme ensures proper range operation when a single power supply is used. The circuit described is especially suited for low consumption, batte...

A new fully differential (FD) low input impedance CMOS current buffer with low voltage, and low power operation is presented. The low input impedance is achieved by remarkable reduction of the input node voltage swing using a novel double feedback scheme. Some advantages of the proposed double feedback scheme over the conventional (either positive or negative) feedback techniques are: lower inp...

A novel high CMRR current output stage (COS) with QFG is presented in this paper. A novel common mode feedback (CMFB) is used to reject the common mode signal in order to achieve high CMRR. The common mode signal is omitted by the technique of adding the main signal and its opposite polarity one. 112 dB of CMRR is obtained in 0.35 μm CMOS technology with ±0.75 v supply voltage and only 182 μw p...