SBOS160A November   1993  – January 2015 ISO122

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  5. 5 Revision History
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 Modulator
      2. 8.1.2 Demodulator
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Isolation Amplifier
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Carrier Frequency Considerations
      2. 9.1.2 Isolation Mode Voltage Induced Errors
      3. 9.1.3 High IMV dV/dt Errors
      4. 9.1.4 High Voltage Testing
    2. 9.2 Typical Application
      1. 9.2.1 Output Filter
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Battery Monitor
      3. 9.2.3 Programmable Gain Amplifier
      4. 9.2.4 Thermocouple Amplifier
      5. 9.2.5 Isolated 4- to 20-mA Instrument Loop
      6. 9.2.6 Single-Supply Operation of the ISO122P Isolation Amplifier
      7. 9.2.7 Input-Side Powered ISO Amp
      8. 9.2.8 Powered ISO Amp With Three-Port Isolation
  10. 10Power Supply Recommendations
    1. 10.1 Signal and Supply Connections
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

10 Power Supply Recommendations

10.1 Signal and Supply Connections

Each power-supply pin should be bypassed with 1-µF tantalum capacitors located as close to the amplifier as possible. The internal frequency of the modulator/demodulator is set at 500 kHz by an internal oscillator. Therefore, if it is desired to minimize any feedthrough noise (beat frequencies) from a DC-DC converter, use a π filter on the supplies (see Figure 24). The ISO122 output has a 500-kHz ripple of 20 mV, which can be removed with a simple 2-pole low-pass filter with a 100-kHz cutoff using a low-cost op amp (see Figure 10).

The input to the modulator is a current (set by the 200-kΩ integrator input resistor) that makes it possible to have an input voltage greater than the input supplies, as long as the output supply is at least ±15 V. It is therefore possible, when using an unregulated DC-DC converter, to minimize PSR related output errors with ±5-V voltage regulators on the isolated side and still get the full ±10V input and output swing.

basic_signal_and_power_conncetions_sbos160.gifFigure 24. Basic Signal and Power Connections