ZHCSF48D March 2016  – May 2017 ISO7740 , ISO7741 , ISO7742


  1. 特性
  2. 应用范围
  3. 说明
  4. 修订历史记录
  5. Pin Configuration and Functions
  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 Power Rating
    6. 6.6 Insulation Specifications
    7. 6.7 Safety-Related Certifications
    8. 6.8 Safety Limiting Values
    9. 6.9 Electrical Characteristics—5-V Supply
    10. 6.10Supply Current Characteristics—5-V Supply
    11. 6.11Electrical Characteristics—3.3-V Supply
    12. 6.12Supply Current Characteristics—3.3-V Supply
    13. 6.13Electrical Characteristics—2.5-V Supply
    14. 6.14Supply Current Characteristics—2.5-V Supply
    15. 6.15Switching Characteristics—5-V Supply
    16. 6.16Switching Characteristics—3.3-V Supply
    17. 6.17Switching Characteristics—2.5-V Supply
    18. 6.18Insulation Characteristics Curves
    19. 6.19Typical Characteristics
  7. Parameter Measurement Information
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagram
    3. 8.3Feature Description
      1. 8.3.1Electromagnetic Compatibility (EMC) Considerations
    4. 8.4Device Functional Modes
      1. 8.4.1Device I/O Schematics
  9. Application and Implementation
    1. 9.1Application Information
    2. 9.2Typical Application
      1. 9.2.1Design Requirements
      2. 9.2.2Detailed Design Procedure
      3. 9.2.3Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1Layout Guidelines
      1. 11.1.1PCB Material
    2. 11.2Layout Example
  12. 12器件和文档支持
    1. 12.1文档支持
      1. 12.1.1相关文档
    2. 12.2相关链接
    3. 12.3接收文档更新通知
    4. 12.4社区资源
    5. 12.5商标
    6. 12.6静电放电警告
    7. 12.7Glossary
  13. 13机械、封装和可订购信息

Application and Implementation


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.

Application Information

The ISO774x devices are high-performance, quad-channel digital isolators. These devices come with enable pins on each side which can be used to put the respective outputs in high impedance for multi master driving applications and reduce power consumption. The ISO774x devices use single-ended CMOS-logic switching technology. The voltage range is from 2.25 V to 5.5 V for both supplies, VCC1 and VCC2. When designing with digital isolators, keep in mind that because of the single-ended design structure, digital isolators do not conform to any specific interface standard and are only intended for isolating single-ended CMOS or 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.

Typical Application

Figure 22 shows the isolated serial peripheral interface (SPI).

ISO7740 ISO7741 ISO7742 typ_app_sch_sllsep4.gif Figure 22. Isolated SPI for an Analog Input Module With 16 Input

Design Requirements

To design with these devices, use the parameters listed in Table 3.

Table 3. Design Parameters

Supply voltage, VCC1 and VCC22.25 to 5.5 V
Decoupling capacitor between VCC1 and GND10.1 µF
Decoupling capacitor from VCC2 and GND20.1 µF

Detailed Design Procedure

Unlike optocouplers, which require external components to improve performance, provide bias, or limit current, the ISO774x family of devices only require two external bypass capacitors to operate.

ISO7740 ISO7741 ISO7742 Design_Requirements_sllsep4.gif Figure 23. Typical ISO7741 Circuit Hook-up

Application Curve

The following typical eye diagrams of the ISO774x family of devices indicates low jitter and wide open eye at the maximum data rate of 100 Mbps.

ISO7740 ISO7741 ISO7742 eye_diagram1_sllsep4.gif
Figure 24. Eye Diagram at 100 Mbps PRBS 216 – 1, 5 V and 25°C
ISO7740 ISO7741 ISO7742 eye_diagram3_sllsep4.gif
Figure 26. Eye Diagram at 100 Mbps PRBS 216 – 1, 2.5 V and 25°C
ISO7740 ISO7741 ISO7742 eye_diagram2_sllsep4.gif
Figure 25. Eye Diagram at 100 Mbps PRBS 216 – 1, 3.3 V and 25°C