Varactor diode is a type of PN junction diode that behaves as a variable capacitor under varying reverse-biased voltage applied to its terminals. It shows this capacitive effect under reverse biased condition only. It has two terminals i.e. anode and cathode. It is also known by other names such as tunning diode or voltage variable … Read more
Pin diode is a type of diode that has p-type and n-type semiconductor material sandwiching an intrinsic layer. The intrinsic layer is a layer of undoped semiconductor material. This is the structural difference between a normal PN junction diode and a PIN junction diode. Like PN junction diode, ‘P’ refers to the positive p-type region, … Read more
A tunnel diode is a heavily doped p n junction diode with a special characteristic of negative resistance. Tunnel Diode was invented in 1957 by Leo Esaki. Hence, this diode is also called an Esaki diode. Leo Esaki noticed that if a semiconductor diode is highly doped with impurities, it (diode) will show negative resistance … Read more
A differential amplifier is an op amp circuit which is designed to amplify the difference input available and reject the common-mode voltage. It is used for suppressing the effect of noise at the output. Since the noise present will be having the same amplitude at the two terminals of the op-amp. So when the difference … Read more
Slew rate is defined as the maximum rate of change of the op amp output voltage per unit of time in the closed-loop configuration under large-signal condition. Slew rate indicates how rapidly the op amp output can change in response to change in the input frequency. It is given as \[ \quicklatex{color=”#000000″ size=20} \boxed{Slew\; rate=\frac{\mathrm{d} … Read more
Peak Detector is a circuit which is used to detect the peaks of the applied input signal. It basically follows the input voltage and stores the peak voltage. It employs a diode and capacitor to implement this function. Types of Peak Detector Active peak detector Passive peak detector Active peak detector Active peak detectors use … Read more
In an open-loop configuration, an ideal operational amplifier (op amp) behave as a comparator. The behaviour of op amp as a comparator is due to infinite open-loop gain. When it is working as a comparator, there are only two outputs possible at the output of op amp. Op amp as a Comparator Figure 1 shows … Read more
A non inverting amplifier is an operational amplifier circuit which produces an amplified output signal which is in phase with the input signal. Non Inverting operational amplifier Figure 1 shows the basic non-inverting operational amplifier. The input signal Vi is applied directly to the non-inverting terminal while one side of resistor R1 is connected to the inverting … Read more
An inverting amplifier is an operational amplifier circuit which produces amplified output that is 180° out of phase to the applied input. Inverting amplifier is also known as inverting operational amplifier or inverting op-amp. Inverting operational amplifier Figure 1 shows the basic inverting operational amplifier. The input signal Vi is applied to the inverting terminal … Read more
Voltage follower is an op-amp circuit that has a voltage gain of unity. It means that whatever voltage is applied at the input of the op-amp, the same voltage comes at the op-amp output. There is no amplification of the voltage. Hence we can say that the output voltage directly follows the input voltage. The … Read more