Aim: Study of op-amp characteristics: CMRR and Slew rate.
Apparatus Required: 741 IC, Multimeter, CRO, Dual power supply (15-0-15 V), and connecting wires.
Theory:
CMRR:
CMRR stands for Common Mode Rejection Ratio. It measures the ability of an operational amplifier to reject common-mode signals, which are signals that appear simultaneously on both the inverting and non-inverting inputs. Ideally, an op-amp should have infinite CMRR, meaning it should reject all common-mode signals perfectly. However, in practical terms, CMRR is finite. For the IC 741 op-amp, the typical theoretical value of CMRR can be around 90 dB to 100 dB, but the practical value might vary based on manufacturing tolerances and environmental conditions
Slew Rate:
Slew rate refers to the maximum rate of change of the output voltage per unit of time. It determines how fast an op-amp can respond to changes in the input signal. Ideally, an op-amp should have infinite slew rate, meaning it can respond instantaneously to changes in the input signal. However, in reality, op-amps have finite slew rates. For the IC 741 op-amp, the typical theoretical value of slew rate is around 0.5 V/ยตs, but the practical value might be slightly lower due to various factors such as load conditions and temperature.
Circuit Diagram:
CMRR:
Slew Rate:
Precautions:
- Do not connect more than 15 v DC supply
- Always check the Dual power supply with a multimeter before connecting it to the circuit
- Connect an input supply such that the corresponding output remains within the range +14 to -14 volts
- Connections should be neat and tight.
