SBOS165A September   2000  – October 2015 OPA627 , OPA637

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Offset Voltage Adjustment
      2. 7.3.2 Noise Performance
      3. 7.3.3 Input Bias Current
      4. 7.3.4 Phase-Reversal Protection
      5. 7.3.5 Output Overload
      6. 7.3.6 Capacitive Loads
      7. 7.3.7 Input Protection
      8. 7.3.8 EMI Rejection Ratio (EMIRR)
        1. 7.3.8.1 EMIRR IN+ Test Configuration
    4. 7.4 Settling Time
    5. 7.5 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 TINA-TI (Free Software Download)
        2. 11.1.1.2 TI Precision Designs
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8 Application and Implementation

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.

8.1 Application Information

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.

OPA627 OPA637 high_speed_instr_amp_gain100.gif Figure 37. High Speed Instrumentation Amplifier, Gain = 100
OPA627 OPA637 high_speed_instr_amp_gain1000.gif Figure 38. High Speed Instrumentation Amplifier, Gain = 1000
OPA627 OPA637 composite_amp_wide_bw.gif Figure 39. Composite Amplifier for Wide Bandwidth
OPA627 OPA637 opa627_dyn_perf_gplus1.gif Figure 40. OPA627 Dynamic Performance, G = 1
OPA627 OPA637 opa627_dyn_perf_gminus1.gif Figure 41. OPA627 Dynamic Performance, G = –1
OPA627 OPA637 opa637_dyn_resp_g5.gif Figure 42. OPA637 Dynamic Response, G = 5

8.2 Typical Application

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.

OPA627 OPA637 typ_app_lpf_sbos165.gif Figure 43. Second Order Low Pass Filter

8.2.1 Design Requirements

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

8.2.2 Detailed Design Procedure

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. OPA627 OPA637 App_EQ_1_SBOS165.gif

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. OPA627 OPA637 App_EQ_2_SBOS165.gif

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.

8.2.3 Application Curve

OPA627 OPA637 D001_sbos165.gif Figure 44. OPA627 2nd Order 25 kHz, Chebyshev, Low Pass Filter