Question

Elaborate the following parameters that is used to characterize an op-amp. State the practical and ideal values for all the parameters

a)Closed-loop gain

b)Open-loop gain

c)Common-mode voltage gain

d) Common-mode Rejection Ratio (CMRR)

e) Slew rate

f) Input bias current

g)Input offset voltage

h) Saturation voltage

Answer 1

Answer closed loop Gain b) Open loop Grain fets draw a opamp Vin Vout Ri Vp R2 14 R, А I+AB closed loop Grain Af Vout Vin R2 As is given by ( for Negative feedback) where А) open loop Gain B feed back factor Practical opamp have Ap a (100-110) DB Ideal is called Gain with feed back closed loop crain. and Gain without feeback is called at open loop Gain. I deal op amp) have open loop Grain (Infinité) 10 V/ Practical op-amp hare open loop Crain

e) common mode voltage Grain (d) CMRR let us take an opamp Common mode voltage op-amp when the applied voltage is common both the inputs as common mode opamp. then it is called Vocomm, V @v Common mode -voltage gain dem Vocomme VI CMRR common-mode Rejection Ratio is the Ratio of differential gain and common mode gain of an opamp. Adm differsential Grain Ad CMRR tem Army Common-mode hain Go to loodB Practical value of CMRR I doal value of CMRR 1) o (Infinite)

slew Rate - slew Rate is given by change of output It is expressed voltage with respect to time. in (volts /us) Votts slew Rate dvo dt de la carte Von output voltage of an Amplifien f) Input Bias cuorent (IIB) R2 Vo Vi - H the Lig is average of corrents I and it where It is inverting terminal current and it is entering into Non-inverting terminal, It It IiB In practical opamp value of Bias corrent is changing opamp speed is changing. LiB CnA to MA) Ideal Ifig = 0 op-amp

9) Input offset voltage Input offect voltage is the voltage that must be applied at the input terminal in order to hullfy (o) the output. Vio Vin -+ Vo Vint Vi RB RA let vi e then Vout = (1 + RB JUSO RA 2 mr (Around) Practical value of Vio Ideal Valve o volt (Ideal op-amp) - h) saturation voltage R2 & Vee & positive saturation voltage RI Tree vo avec Negative saturation vi Voltage, when opamp is not giving output voltage in the limits of input voltage (less than the vij when it saturate the it will provide gaturated output voltage Vo = ± Vee accosting to amplifier. Orequel and