SBOS165A September 2000 – October 2015 OPA627 , OPA637

PRODUCTION DATA.

- 1 Features
- 2 Applications
- 3 Description
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

The OPA627 and OPA637 are ideally suited to use as input amplifiers in instrumentation amplifier configurations requiring high speed, fast settling and high input impedance.

Low pass filters are commonly employed in signal processing applications to reduce noise and prevent aliasing. The OPA627 and OPA637 are ideally suited to construct high speed, high precision active filters. Figure 43 illustrates a second order low pass filter commonly encountered in signal processing applications.

Use the following parameters for this design example:

- Gain = 5 V/V (inverting gain)
- Low pass cutoff frequency = 25 kHz
- Second order Chebyshev filter response with 3-dB gain peaking in the passband

The infinite-gain multiple-feedback circuit for a low-pass network function is shown in Figure 43. Use Equation 1 to calculate the voltage transfer function.

Equation 1.

This circuit produces a signal inversion. For this circuit the gain at DC and the low pass cutoff frequency can be calculated using Equation 2.

Equation 2.

Software tools are readily available to simplify filter design. WEBENCH® Filter Designer is a simple, powerful, and easy-to-use active filter design program. The WEBENCH Filter Designer lets you create optimized filter designs using a selection of TI operational amplifiers and passive components from TI's vendor partners. Available as a web based tool from the WEBENCH® Design Center, WEBENCH® Filter Designer allows you to design, optimize, and simulate complete multi-stage active filter solutions within minutes.