(a) Slew Rate:
i) Slew rate can be defined as maximum possible rate of change of op-amp output voltage.
$\hspace{2cm}SR=\frac{dV_0}{dt}|_{max}\,\,\,(V/\mu sec) $
$\hspace{8cm}$, ideally SR should be infinity.

ii) The slew rate imposes high frequency limitations on the device.
iii) At some critical frequency, an output swing equal to the supply voltages will require a slew rate faster than the maximum slew rate of device.
iv) Slewing is an undesirable effect in high speed circuits that process large signals.
v) The large signal speed is limited by the slew rate simply baecause the current available to charge and discharge the dominant capacitor in the circuits is small.
vi) Since the input-output relationship during slewing is non-linear, the output of slewing amplifier exhibits distortion.

(b) CMRR:Commmom Mode Rejection Ratio
i) The ratio of differential gain $A_d$ to common mode gain of an op-amp.
$ \hspace{2cm} \therefore\,\,CMRR=\frac{A_d}{A_{cm}}$
$ \hspace{2cm} \therefore\,\,CMRR=0\hspace{2cm}$.......(ideally)

ii) However,due to mismatches, $A_{cm}\neq 0$
$\hspace{2cm} \,\,CMRR=\frac{A_d}{A_{cm}} \approx$ very high but finite.

iii) Differential amplifier have an ability to cancel out or reject certain types of undesired signals.
iv) A measure of these rejections of signal is CMRR.

(c) Input range limitations:
i) The op-amp circuits are developed to achieve large differential output swings.
ii) While the differential input swings are usually much smaller, the input CM level may need to vary over a wide range in some applications.
iii) Consider aa case of unity gain buffer,
$\hspace{2cm}$ here, input swing $\approx$ output swing.
$\hspace{1cm}\therefore\,\,\,$ voltage swings are limited by input differential rather than output cascode branch.
iv) Specially $V_{in,min}\,\approx\,V_{out,min}=GV_{GS1,2}+V_{\pm SS}$
approximately one threshold voltage highher than the allowable minimum provided by $M_5-M_6$.

(d) PSRR: Power Supply Rejection Ratio
i) It is defined as change in op-amp input offset voltage caused by variation in supply voltage.
$\hspace{2cm} \therefore\,\,\,PSRR=\frac{dV_{io}}{dV}$