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Unformatted text preview: 53 Op Amp's input offset voltage. Also the negative saturation of the LF353
Op Amp is slightly more negative at -4.5 V when compared to the UA741CP's at -3.99 V. Given the measurement parameters the minimum open loop gain (ΔVout/Δvin)
resuin the linear region is is (9.49V/(.2mV) resulting in a gain of 47450 dB for the UA741CP Op amp and (9.78V/.0002mV)= 48900 dB. The open loop input bias current graph
gives us I(ib) of 32.3nA and 9.22pA for the UA741CP and LF353 respectively. Using the maximum voltage in our sweep and dividing it by the input bias current results in the
input resistance of .309MΩ and 1.09E9 Ω for the UA741CP and LF353 respectively. Our input bias currents are on the same order of maginitude as the spec sheet which implies
that the difference may be due to manufacturing variations. The input resistance however are off by multiple magnitudes (.309MΩ vs. 2MΩ) and (1.09EΩ vs. 10E12Ω).
These values are off because using the maximum input voltage in our sweep and input bias currents are a poor approximation of the resistance ECE2100 Lab #5 - Operational Amplifier Circuits Page 2 of 4
Inverting Amplifier with the UA741CP
Inverting Amplifier Test CircuitInverting Amplifier Voltage Transfer Characteristic
SMU1:V sweep -100mV to 100mV, 101 steps, 1 mA Compliance
Vout vs. Vin for Diff. Loads
SMU2: Voltmeter 6.2 V Compliance
4.00E+00 Vout ( V) (place cloed loop voltage transfer characteristics here.
one set of axes. 1 curve for the unloaded case
and 1 curve for each load used. Label slope clearly)
Column N 0.00E+00 -2 .00E+00 Input Voltage Linear Range
-59.9 to +38
-17.9 to +20
-51.9 to +32
-2.00E-01 -1.00E-01 0.00E+00 1.00E-01 2.00E-01
-53.9 to +34
-49.9 to +34 Voltage Gain = 20log|vout/vin| = 20log|-87.26|= 38.81 dBs
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This note was uploaded on 01/22/2014 for the course ECE 2100 taught by Professor Kelley/seyler during the Fall '05 term at Cornell.
- Fall '05