parameters of op-amp m.s.p.v.l polytechnic college, pavoorchatram
TRANSCRIPT
Parameters of OP-AMP
M.S.P.V.L Polytechnic College,Pavoorchatram.
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Circuit Symbols of OP-AMP
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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 productwww.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.
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Input offset voltage
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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).
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Input offset current
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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
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Input BIAS current
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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.
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Large Signal voltage Gain
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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.
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Output Voltage Swing
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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.
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Differential Input Resistance Ri
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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.
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Input Capacitance Ci
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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
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Common Mode Rejection Ratio
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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
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Supply Voltage Rejection Ratio
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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
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Slew Rate
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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.
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Gain Bandwidth Product
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The End
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