SLLSE39E June   2010  – May 2015 ISO7520C , ISO7521C

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: VCC1 and VCC2 at 5 V ± 5%
    6. 6.6  Electrical Characteristics: VCC1 at 5 V ± 5%, VCC2 at 3.3 V ± 5%
    7. 6.7  Electrical Characteristics: VCC1 at 3.3 V ± 5%, VCC2 at 5 V ± 5%
    8. 6.8  Electrical Characteristics: VCC1 and VCC2 at 3.3 V ± 5%
    9. 6.9  Switching Characteristics: VCC1 and VCC2 at 5 V ± 5%
    10. 6.10 Switching Characteristics: VCC1 at 5 V ± 5%, VCC2 at 3.3 V ± 5%
    11. 6.11 Switching Characteristics: VCC1 at 3.3 V ± 5%, VCC2 at 5 V ± 5%
    12. 6.12 Switching Characteristics: VCC1 and VCC2 at 3.3 V ± 5%
    13. 6.13 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Insulation Characteristics
      2. 8.3.2 IEC 60664-1 Ratings Table
      3. 8.3.3 Package Insulation and Safety-Related Specifications
      4. 8.3.4 Safety Limiting Values
      5. 8.3.5 Regulatory Information
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 PCB Material
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9 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.

9.1 Application Information

The ISO7520C and ISO7521C are high-performance, dual-channel digital isolators with a 5-kVRMS isolation voltage. The isolator uses single-ended TTL-logic switching technology. The supply voltage range is from 3.15 V to 5.25 V for both supplies, VCC1 and VCC2. When designing with digital isolators, it is important to keep in mind that due to the single-ended design structure, digital isolators do not conform to any specific interface standard and are only intended for isolating single-ended TTL digital signal lines. The isolator is typically placed between the data controller (that is, μC or UART), and a data converter or a line transceiver, regardless of the interface type or standard.

9.2 Typical Application

The ISO7521C can be used with Texas Instruments' mixed signal micro-controller, digital-to-analog converter, transformer driver, and voltage regulator to create an isolated 4- to 20-mA current loop.

ISO7520C ISO7521C Isolated_339.gifFigure 10. Isolated 4-20 mA Current Loop

9.2.1 Design Requirements

For the ISO7521C, use the parameters shown in Table 2.

Table 2. ISO752xC Design Parameters

PARAMETER VALUE
Supply voltage 3.15 V to 5.25 V
Decoupling capacitor between VCC1 and GND1 0.1 µF
Decoupling capacitor from VCC2 and GND2 0.1 µF

9.2.2 Detailed Design Procedure

Unlike optocouplers, which need external components to improve performance, provide bias, or limit current, the ISO7521C only needs two external bypass capacitors to operate.

ISO7520C ISO7521C Typical_ISO7521C_Circuit_Hook-Up_SLLSE39.gifFigure 11. Typical ISO7521C Circuit Hook-up

9.2.3 Application Curve

ISO7520C ISO7521C g005_lls984.gifFigure 12. Input Voltage Switching Threshold vs Free-Air Temperature