**1 Answer**

written 2.6 years ago by |

CMRR, slow rate, Gain Bandwidth product, input offset voltage and output resistance.

**1] CMRR (common mode rejection ratio):**

The ratio of differential gain and common mode gain is defined as CMRR, thus, infinite CMRR of an ideal op-amp ensures zero common mode gain, because of this, common mode noise output voltage is zero for an ideal op-amp.

Ideally = $\infty$

Practically = 90dB

**2] Slow rate:** It is the maximum change in output voltage with respect to unit time.

It is defined as rate of change of o/p voltage with time.

$slow \ rate = \frac{dvo}{dt}| \ max$

Higher the slow rate, more will be the allowed frequency for the given ckt.

Therefore, it must be as high as possible, Ideally $\infty$, practically s = 0.5v/ $\mu$ sec

**3] Gain bandwidth product:** The gain bandwidth product for an amplifier is the product of the amplifiers bandwidth and the gain at which the bandwidth is measured.

Ideally = $\infty$

Practically = 1 $MH_2$ (80dB, 100 H2)

**4] Input offset voltage:** Ideally for zero input, the o/p of an op-amp should be zero.
practically, due to large voltage gain, o/p of op-amp is not equal to o even, if input are 0. this non zero voltage at output is known as output offset voltage.

To make output offset zero, we need to apply small differential voltage at input known as input offset voltage (Vios)

Ideally = 0

Practically = 6 MV

**5] Output resistance:** It is typically few hundred ohms, with the application of negative feedback, it can be reduced to a very small value.

Ideally = 0

typically = 75