It should give high enough gain and it is not very complex, it should thereby be easy to get sufficiently high unity gain frequency and it should not degrade the performance of the overall amplifier too much. One of the various compensation circuits Rc, Cc is also shown in Figure 2. In essence, the input voltage offset is also the voltage that needs to be applied across the inputs of an op amp to make its output zero. Gain and speed are the two important parameters of the operational amplifier. Ml and M2 form the main cascode amplifier. The operating principle is as follows:

Solid State Circuits, vol. When they were working according to the demands, they were connected to the main amplifier and the performance of the overall amplifier was verified. I would also like to thank Mr. In [17] a regulated cascode stage has been presented that increases the gain of a normal cascode stage without affecting the frequency behavior to a large extent. Hence at this point even transistor T 1 leaves saturation and enter the ohmic region. The output of these auxiliary 53 amplifiers is providing an output voltage to bias the gates of M2 and M1.

The FinFET has a conducting channel wrapped by a thin silicon “fin” from which it gains its name. The main stage used is the telescopic cascode differential amplifier. For low off-current, bulk MOS-devices need utterly high channel doping, which decreses carrier mobility. As is shown in Chapter 3, too much increase in current might also lead to instability because high currents in the additional stage will give high operstional gain frequency for the additional stage and the relationship given in Sections 3.

A 90 dB, 85 MHz operational transconductance amplifier (OTA

To control theamplifier’s transconductence we use additional input for a current. An OTA can only drive capacitive loads. This design overcomes various limitations and drawbacks of the various previously presented described architectures. The main reason for development of such technologies are their scope for reduction in their physical size. It is measured in dB. For single pole amplifiers this is the product of the op amp’s open-loop voltage gain and the frequency at which it was measured.


A 90 dB, 85 MHz operational transconductance amplifier (OTA

These factors can be taken care during the designing of the amplifier and additional gain stages. This thesis presents operatiojal 90 dB, 85 MHz gain bandwidth telescopic cascode amplifer using the gain boosting technique.

Rakhi Tomar, Assistant proffessorJaypee Institute of Information Technology, India for her generous guidance, help and useful suggestions. The output resistance of this circuit is Rout – A3gm2ro1,r02where A3 is the gain of the feedback transistor T3. The telescopic cascode design starts with the sizing of the main differential input pair thexis transistors MO and M4 using the desired phase margin and gain bandwidth specifications.

The simplest implementation of the additional gain stages used in this design is a single transistor transonductance source amplifier. One of the various compensation circuits Rc, Cc is also shown in Figure 2.

The increase in gate voltage of T2 is taken care of by the feedback loop. Sanasi Ramanan for their time to review this manuscript. Since the gain only had to be increased by about 15 dB, a NMOS common source amplifier biased with a cascode current source was chosen as gain-boost amplifier. I hereby certify that, if appropriate, I have obtained and attached written permission statements from the owners of each third party copyrighted matter to be included in my thesis.


Sometimes it is used to describe any fin-based, multigate transistor architecture regardless of number of gates. Thesus e-mail Input it if you want to receive answer. The size of transistors is decreasing and power supply is also decreasing due to recent development in VLSI technology.

operational transconductance amplifier thesis

The thickness of the fin determines the effective channel length of the device. R load The voltge gainn is thenthe ouptut voltge divaided bythe differensial ipnut voltge: Hence the drain-source voltage of T 1 is regulated to a fixed value.

operational transconductance amplifier thesis

Pole Zero locations qmplifier a non-optimized gain boosted amplifier. Care has to be taken not to make the input pair too big to affect the bandwidth and at the same time making them big enough to provide enough transconductance and hence the gain. Output Common Mode Range: You can add this document to your saved list Sign in Available only to authorized users. It permits low supply voltage, still having a rather high output voltage swing and the input and output common mode levels can be designed to be equal.

This is the maximum voltage negative or positive that can be applied at both inputs of an operational amplifier at the same time, with respect to the ground. This will have to be taken into consideration before the telescopic design is used in a larger circuit.

Later the design of a high gain amplifier using this regulated cascode configuration is presented t. For complaints, use another form.