Category Archives: Analog electronics

Operation and construction of Enhancement type Mosfet

At its name indicates, this MOSFET operates only in the enhancement mode & has no depletion mode. It works with large positive gate voltages only. It differs in construction from the DEMOSFET in that structurally there exists no channel between the drain & source” which shown in figure below. Hence it does not conduct when VGS=0 i.e. why… Read More »

Class B Power Amplifier

Class B amplifier is a type of power amplifier where the active device (transistor) conducts only for half cycle obey input signal. That means the conduction angle is 180 degree for a class B amplifier. Since the active device is switched off for half the input cycle, the active device dissipates less power hence the efficiency is improved.… Read More »

Frequency response of OP-AMP

OP-AMP Bandwidth, frequency response & gain bandwidth product are key parameters for any circuit. Typically, OP-AMPs are used for comparatively low frequency circuit but with the performance of these chips is improving all the time, much higher bandwidth OP-AMPs are available. The frequency response response of a typical OP-AMP chip will often start to fall at a very… Read More »

JFET as an amplifier

JFET as an amplifier- The weak signal is applied between gate and source, and amplified output is obtained across drain and source terminal. For proper operation of JFET gate must be negative with respect to source. Input circuit should always be reversed biased with help of a battery Vgg or by a circuit is known as biasing circuit.… Read More »

Working of JFET

Working of JFET- The two P-N junctions at the sides form two depletion layers. The current conduction by charge carrier i.e. electrons in case of N-channel JFET is thought the channel between two depletion layers and out of drain. The width and hence resistance of this channel can be control by changing the input voltage Vgs. The greater… Read More »