ELE541 E-Testing II

Figure 1


Figure 2   Instrumentation Amplifier

Opamp exam problems

  1. What is the effect of a 1 uA input bias current on the output of the circuit shown in Figure 1?
    Answer

  2. What is the effect of a 5 mV input offset voltage on the output of the circuit shown in Figure 1?
    Answer

  3. What is the gain of the instrumentation amplifier shown in Figure 2?
    Answer

  4. For the ELE541 opamp described in Table 1, what is the maximum output amplitude that a 500KHz signal can have before it becomes distorted due to power bandwidth limitations?
    Answer

    ELE541 OPAMP
    Characteristics Symbol   Unit
    Input Offset Voltage VIO 2.0 mV
    Input Offset Current IIO 100 nA
    Input Bias Current IIB 500 nA
    Input Resistance ri 2 Meg
    Output Resistance ro 75 Ohms
    Open Loop Gain Aol 106 dB
    Gain Bandwidth fT 4 MHz
    Slew Rate SR 0.5 V/us

    Table 1     Opamp Characteristics