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...

X-parameters are developed as a superset of S-parameters and they are suitable for modeling systems having only radio-frequency (RF) and DC ports. For a polar power amplifier (PA), the envelope of the input modulated signal is applied at the envelope port, which is neither an RF nor a DC port. In this case, X-parameter may fail to characterize the behavior of the envelope path and consequently ...

approved: Andreas Weisshaar In cellular telephones, RF power amplifiers consume a significant part of the total phone current. Reducing the average PA current will extend battery life. In GSM systems the handset is commanded by the base station to transmit at power levels lower than full power much of the time. A Doherty amplifier can be used to improve efficiency at these lower power levels, p...

Power consumption is a key point in the design of high-speed switched capacitor (SC) circuits, which allow to efficiently implement a number of analog functions. Among them, SC Σ∆ modulators are very popular for A/D conversion: in this kind of circuits, operational amplifiers are the most consuming cells because of their requirements in terms of DC gain and unitygain frequency. A new amplifier ...

Abstract Low‐frequency noise, generated inherently by the number or mobility fluctuation of carriers, is a crucial concern for design analog and digital circuits. Unified modelling based on experimental validation near‐DC noise in amplifiers long‐standing open problem. This article develops model low‐frequency deriving new bounds carrier capturing releasing. According to proposed model, measure...

System common mode rejection ratio (SCMRR) and interference (CMI) range are two critical design specifications for multiple-channel neural recording front-end circuit in a freely moving animal experiment environment. This letter presents amplifiers array consisting of 15 DC-coupled inverter-based channels, reference channel shared voltage averaging (VAC) with floating rail Common Mode Feedback ...

This note describes a number of techniques that can be used to detect low level optical signals. It starts by considering the problems inherent in the use of DC techniques and how these may be reduced by using AC methods instead. It then discusses a range of different experimental approaches using lock-in amplifiers, pointing out the advantages as well as any disadvantages of each method. Final...

A full custom design of a three-stage amplifier is described in this paper. A feedback transconductance stage and a feedforward stage combined with two Miller compensation capacitors are used for frequency compensation. The circuit is designed in 0.18μm CMOS process with a 1.8V supply voltage. When driving a 150pF capacitive load, the amplifier achieves over 100dB dc gain, 2.24MHz gainbandwidth...

In this paper, a cardiac sense amplifier, i.e. the front end of a pacemaker, based on the Dynamic Translinear (DTL) circuit technique is presented. The system consists of a voltage-to-current converter, a bandpass filter, absolute value and RMS-DC converter circuits and an event detection circuit. From simulations, it is demonstrated that the DTL technique is a good alternative to conventional ...

We present a method for the measurement of the noise of microwave amplifiers operating at the single photon level. It is based on the shot noise produced by a nanowire resistor in the hot electron regime. This noise source is simply controlled by a dc current and offers the advantage of being self-calibrating. After testing the noise source with a cryogenic high electron mobility transistor amp...