In this article we will discuss about programmable operational amplifier IC, its key parameters, applications, parts number and comments.
Programmable Operational Amplifier Description
Some general-purpose op amps are available with an external tab that can be connected to a “set” or programmable current. This external terminal can control such important parameters as the power dissipation, bandwidth, slew rate, output current, input impedance, and input noise. While the programming current controls some of these parameters, other parameters will remain fixed.
Externally supplied programming current can be in the form of a fixed resistor, a potentiometer or a current source. If the set or programming current varies rapidly over a fixed range, the programmable, or variable frequency active filter. In addition to general purpose op amps, some types of low-power and high-frequency op amps are also programmable.
Figure 1: Programmable Operational Amplifier IC
Key Parameters of Programmable Operational Amplifier
Essentially the same as general purpose or low power op amps except the following:
- Set current range: 1 to 100mA.
- Bandwidth: The frequency range over which it response are 5 kHz to 10 MHz (typically) variation over the set current range.
- Slew rate: Maximum rate of change of the output voltage for an input step-voltage change are 0.06V/us to 6 V/us (typical) variation over the set current range.
- Input resistance: Represented accurately by a parallel R-C circuit across the input terminal, 50 to 5 megaohms (typical) variation over the set current range.
Applications
Programmable op amps are particularly useful for the experimental design phase, where final specification’s are yet to be determined and a range of adjustment of key parameter’s is important. They are also found in variable frequency active filters, current controlled oscillators, and modulators.
Representative Part Number: Precision Monolithic OP-22.
Comments
The manufacturers’ detailed specifications should be carefully reviewed for details of the set or programming current requirements and the parameter changes obtainable with set current changes.