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Parameters of OP-AMP. M.S.P.V.L Polytechnic College, Pavoorchatram. Circuit Symbols of OP-AMP. Parameters of OP-AMP. Input offset voltage Input offset current Input BIAS current Large signal voltage gain Output voltage swing Differential input resistance Ri. Input capacitance Ci
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Parameters of OP-AMP M.S.P.V.L Polytechnic College, Pavoorchatram. www.ustudy.in
Circuit Symbols of OP-AMP www.ustudy.in
Parameters of OP-AMP • Input offset voltage • Input offset current • Input BIAS current • Large signal voltage gain • Output voltage swing • Differential input resistance Ri • Input capacitance Ci • Common mode rejection ratio • Supply voltage rejection ratio • Slew rate • Gain bandwidth product www.ustudy.in
Input offset voltage • Input offset voltage is the voltage that must be applied between the two input terminals of an op-amp to null the output. • Typical value of 741 IC is 6mV dc. www.ustudy.in
Input offset voltage www.ustudy.in
Input offset current • The algebraic difference between the current in the inverting and non inverting terminal is known as the input offset current Iio. • As the matching between two terminals increases,the difference between IB1 and IB2 become smaller. • Typical value for 741 IC is 200mA(max). www.ustudy.in
Input offset current www.ustudy.in
Input BIAS current • IB is the average current flows in the Inverting and Non-Inverting terminal of OP-AMP. IB = (IB1 + IB2 )/2 • Typical value for 741 is 500mA www.ustudy.in
Input BIAS current www.ustudy.in
Large Signal voltage Gain • It is the ratio of the output voltage and the differential input voltage. A= Output voltage/Differential input = Vo/Vid • Typical value for 741 IC is 200,000. www.ustudy.in
Large Signal voltage Gain www.ustudy.in
Output Voltage Swing • This parameter indicates the values of positive and negative saturation voltage of the op- amp. • For 741IC,it is +13 and -13V. www.ustudy.in
Output Voltage Swing www.ustudy.in
Differential Input Resistance Ri • Differential input resistance Ri is the equivalent resistance that can be measured at either the inverting or non-inverting input terminals with the other terminal connected to ground. • Typical value for 741 IC is 2 mega ohm. www.ustudy.in
Differential Input Resistance Ri www.ustudy.in
Input Capacitance Ci • Input capacitance is the equivalent capacitance that can be measured at either the inverting or non-inverting input terminal with the other terminal connected to ground. • Typical value for a 741 IC is 1.4 pF. www.ustudy.in
Input Capacitance Ci www.ustudy.in
Common Mode Rejection Ratio • When the same voltage is applied to both the input terminals the voltage is called a common mode voltage Vcm and the op-amp is said to be operating in the common mode configuration • CMRR is defined as the ratio of the differential voltage gain to common mode gain. CMRR = Ad/Acm www.ustudy.in
Common Mode Rejection Ratio www.ustudy.in
Supply Voltage Rejection Ratio • The change in an op-amps input offset voltage Vio caused by variations in the supply voltage is called the SVRR. • It is expressed in microvolts per volt or in decibels. SR= ΔVio/ΔV • Typical value for a 741IC is 150μV/V www.ustudy.in
Supply Voltage Rejection Ratio www.ustudy.in
Slew Rate • Slew rate is defined as the maximum rate of change of output voltage per unit of time and is expressed as volt per micro second. SR=(|dVo|/|ds|)max ie V\μs www.ustudy.in
Slew Rate www.ustudy.in
Gain Bandwidth Product • The gain bandwidth product(GB) is the bandwidth of the op-amp when the voltage gain is 1. • Typical value for 741 IC is 1MHz. www.ustudy.in
Gain Bandwidth Product www.ustudy.in
The End …… Thank You …… www.ustudy.in
