MC33171 Low Power Operational Amplifier IC

MC33171/72/74 is a bipolar operational amplifier. The operation of this device is specified over a voltage range of 3V to 44V. It belongs to MC33171/72/74, NCV33172/74 series. This operational amplifier is a high-power IC that can perform almost all applications of the standard operational amplifiers and is pin to pin compatible with the old basic operational amplifiers. Moreover, it supports a bandwidth of 1.8MHz and consumes a very low current per amplifier.

Pin Configuration Diagram

As it is an operational amplifier, therefore it has 2 inputs and 1 output pin. The figure below shows a pinout diagram.

MC33171 pinout diagram bipolar operational amplifier

An additional input of offset Null is also provided. All the pins of this IC and their functionalities are mentioned in the table below:

Pin NumberPin NameDescription
1, 5Offset NullIt is used for setting offset voltage.
2Inv. InputInverting input terminal of opamp
3Noninv. InputNon-Inverting input terminal of opamp
4Ground of the circuit
6OutputOutput of opamp
7Positive power supply
8NCNot Connected

MC33171 Low Power Operational Amplifier Features

  • Low consumption of only 200µa
  • Good speed of 2.1MHz in 2vµs
  • Operating temperature range of -40°C to +105°C
  • Pin to Pin compatible with other single operational amplifiers
  • Wide input common mode range, including Ground (VEE)
  • Pin to pin compatible with standard single op-amps
  • Wide Bandwidth of 1.8 MHz and High Slew rate of 2.1 V/µs
  • high input resistance, low input offset voltage and high gain.
  • Excellent Gain Margin of 15 dB
  • Output Short Circuit Protection
  • ESD Diodes to protect inputs against static discharges

Equivalent Op-Amps

MC33172, MC33174, NCV33172/74

Other Alternative Amplifiers

Where to use MC33171?

We can use this IC in electrical and electronics circuits. You can use this IC to perform integration operations by connecting a capacitor in the feedback loop. The output signal produced will be directly proportional to the amplitude and duration of the input signal. This IC can also be used for voltage to current conversions by applying a voltage to the non-inverting terminal and negative feedback. Some other uses of this IC are in designing of voltage follower circuits, selective inversion circuits, Active Filters, etc.

How to use MC33171 Op-Amp?

This IC is very easy to use. We can use IC MC33171 as an inverting amplifier and a noninverting amplifier. In inverting mode, a voltage signal is applied at pin2 and pin 3 is grounded. The polarity of the output signal obtained in this mode is opposite to the input signal.

Vout = (-Rf/R1) Vin

The circuit diagram for the inverting amplifier is given below. For a non-inverting amplifier, connect the pin 3 with a voltage signal and pin 2 is grounded. Then the polarity of output obtained will be the same as the polarity of the input signal. The equation for the non-inverting amplifier is:

inverting amplifier circuit

Vout = (Rf/R1) Vin

The value of input voltages applied must lie between the values of supply voltages VEE and Vcc.

MC33171 Op-Amp Example Circuits

Operational amplifiers have a wide variety of applications in electrical circuits. Some of them are:

Sample and Hold Circuit Example

This example circuit shows a Sample and Holds circuits using this MC33171 op-amp. We need two op-amps that connect through a switch as shown in the circuit diagram below. When the switch closes, the capacitor charges to its peak value and the sampling of the input signal performs whereas in hold form, the switch will be open and the capacitor holds the value.

MC33171 sample and hold circuit example

Peak Detector Circuit

In this example circuit of MC33171, we design a peak detector by connecting a capacitor and diode at its output as shown in the circuit diagram below. The diode will conduct and is forward biased when Vout is greater than Vin. On the other hand, if Vout is less than Vin diode will not conduct.

MC33171 Peak detector circuit example

Comparator Circuit Example

It can act as a voltage comparator by applying reference voltage on pin 2 and voltage to be measured on pin 3 of the IC MC33171. If the output is positive that means voltage to be measured is greater than the reference voltage.

Functional Generator Circuit

Function Generators are also designed through two operational amplifiers which can be achieved by using two IC’s of MC33171.


This is a 2D diagram for 8 pin PDIP package of IC MC33171.

 2D Diagram


MC33171 Op-Amp Datasheet

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