The impact of high-voltage-high-frequency (HVHF) amplifiers on echo-signal quality is greater with very-high-frequency (VHF, ≥100 MHz) ultrasound transducers than with low-frequency (LF, ≤15 MHz) ultrasound transducers. Hence, the bias voltage of an HVHF amplifier must be stabilized to ensure stable echo-signal amplitudes. We propose a bias-voltage stabilizer circuit to maintain stable DC volta...

1) Institut GOŠA d.o.o., Milana Rakića 35, 11000 Belgrade, SERBIA 2) Faculty of Electrical Engineering, Bul. kralja Aleksandra 73, 11120 Belgrade, SERBIA Introduction ANY industrial electronic control systems are designed to operate using only a single-power-supply voltage. The conventional integrated-circuit operational amplifier (IC op amp) is typically designed for split power supplies (±15 ...

AbstractChopping is a proficient way to reduce the low frequency offset and 1/f noise in amplifiers. In this paper, a low power low noise CMOS chopper amplifier is presented. It is composed of a two stage amplifier. The first stage’s high output impedance and the equivalent Miller capacitance of the second stage constitute together a low pass filter, which reduces the power consumption. The cir...

A complementary bipolar low-power, high-speed, current-feedback operational amplifier is described. The amplifier incorporates a new Class AB output stage that enables high output current drive of 100 mA and large voltage swing within 1 V of the supply rails while operating at low quiescent current of 1.5 mA. The amplifier was fabricated in a junction-isolated complementary bipolar process with...

A new BiCMOS variable gain transimpedance amplifier with a large area integrated photodiode for automotive applications is presented. Through careful control of the input pole position and the frequency response of the core amplifier, the bandwidth of the transimpedance amplifier varies from 112 to 300 MHz when its gain changes from 14.2 kV to 400 V. The proposed circuit configuration maintains...

For low-voltage, low-power circuit design, the linear model for operational amplifiers is insufficient to accurately predict the static and dynamic behavior of the circuit. This paper introduces a nonlinear model for operational amplifiers based on amplifiers’ DC transfer characteristic. By using this nonlinear model, the behavior of an operational amplifier with feedback network can be describ...

Nonlinearity estimation and spectral regrowth prediction are crucial to power amplifier linearization. The correlation techniques shown here can estimate amplifier nonlinearity and predict out-of-band power spectrum. Crosscorrelation is performed between the output envelope and a test sequence generated from the input signal and can be carried out in background during amplifier operations. The ...

This paper presents a capacitor-less low drop-out (LDO) regulator with current mode transconductance amplifier & slew-rate enhancement circuit. The proposed current mode transconductance amplifier as error amplifier improves the slew rate & slewrate enhancement circuit further senses the transient voltage at the output of the LDO to increase the bias current of the error amplifier for a short d...

Accurate FET Model parameters need to be determined to give accurate simulation results for RF amplifiers. The accuracy required varies depending on the application of the final amplifier. For Doherty amplifiers, a high accuracy is required for the transfer characteristic of the amplifier. An amplifier was simulated using a model obtained from data sheet information, and then built. Measurement...

A high-efficiency class-E power amplifier is proposed for digital PWM microwave signal amplification in the improved Kahn Technique transceiver. The benefit of using a class-E power amplifier in this design approach is to improve efficiency of the power amplifier due to its switching mode operation, theoretically 100 % with ideal conditions. In this paper a class-E amplifier is designed for the...