ZHCSF48D March 2016  – May 2017 ISO7740 , ISO7741 , ISO7742

PRODUCTION DATA. 

  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

Detailed Description

Overview

The ISO774x family of devices have an ON-OFF keying (OOK) modulation scheme to transmit the digital data across a silicon dioxide based isolation barrier. The transmitter sends a high frequency carrier across the barrier to represent one digital state and sends no signal to represent the other digital state. The receiver demodulates the signal after advanced signal conditioning and produces the output through a buffer stage. If the ENx pin is low then the output goes to high impedance. The ISO774x devices also incorporate advanced circuit techniques to maximize the CMTI performance and minimize the radiated emissions due the high frequency carrier and IO buffer switching. The conceptual block diagram of a digital capacitive isolator, Figure 19, shows a functional block diagram of a typical channel.

Functional Block Diagram

ISO7740 ISO7741 ISO7742 fbd_sllsej0.gif Figure 19. Conceptual Block Diagram of a Digital Capacitive Isolator

Figure 20 shows a conceptual detail of how the ON-OFF keying scheme works.

ISO7740 ISO7741 ISO7742 on_off_keying_sllsem2.gif Figure 20. On-Off Keying (OOK) Based Modulation Scheme

Feature Description

Table 1 provides an overview of the device features.

Table 1. Device Features

PART NUMBERCHANNEL DIRECTIONMAXIMUM DATA RATE DEFAULT OUTPUTPACKAGERATED ISOLATION(1)
ISO77404 Forward,
0 Reverse
100 MbpsHighDW-165000 VRMS / 8000 VPK
DBQ-162500 VRMS / 3600 VPK
ISO7740 with F suffix4 Forward,
0 Reverse
100 MbpsLowDW-165000 VRMS / 8000 VPK
DBQ-162500 VRMS / 3600 VPK
ISO77413 Forward,
1 Reverse
100 MbpsHighDW-165000 VRMS / 8000 VPK
DBQ-162500 VRMS / 3600 VPK
ISO7741 with F suffix3 Forward,
1 Reverse
100 MbpsLowDW-165000 VRMS / 8000 VPK
DBQ-162500 VRMS / 3600 VPK
ISO77422 Forward,
2 Reverse
100 MbpsHighDW-165000 VRMS / 8000 VPK
DBQ-162500 VRMS / 3600 VPK
ISO7742 with F suffix2 Forward,
2 Reverse
100 MbpsLowDW-165000 VRMS / 8000 VPK
DBQ-162500 VRMS / 3600 VPK
See Safety-Related Certifications for detailed isolation ratings.

Electromagnetic Compatibility (EMC) Considerations

Many applications in harsh industrial environment are sensitive to disturbances such as electrostatic discharge (ESD), electrical fast transient (EFT), surge and electromagnetic emissions. These electromagnetic disturbances are regulated by international standards such as IEC 61000-4-x and CISPR 22. Although system-level performance and reliability depends, to a large extent, on the application board design and layout, the ISO774x family of devices incorporates many chip-level design improvements for overall system robustness. Some of these improvements include:

  • Robust ESD protection cells for input and output signal pins and inter-chip bond pads.
  • Low-resistance connectivity of ESD cells to supply and ground pins.
  • Enhanced performance of high voltage isolation capacitor for better tolerance of ESD, EFT and surge events.
  • Bigger on-chip decoupling capacitors to bypass undesirable high energy signals through a low impedance path.
  • PMOS and NMOS devices isolated from each other by using guard rings to avoid triggering of parasitic SCRs.
  • Reduced common mode currents across the isolation barrier by ensuring purely differential internal operation.

Device Functional Modes

Table 2 lists the functional modes for the ISO774x devices.

Table 2. Function Table(1)

VCCI VCCO INPUT
(INx)(3)
OUTPUT ENABLE
(ENx)
OUTPUT
(OUTx)
COMMENTS
PUPUHH or openHNormal Operation:
A channel output assumes the logic state of its input.
LH or openL
OpenH or openDefaultDefault mode: When INx is open, the corresponding channel output goes to its default logic state. Default is High for ISO774x and Low for ISO774x with F suffix.
XPUXLZ A low value of output enable causes the outputs to be high-impedance.
PDPUXH or openDefaultDefault mode: When VCCI is unpowered, a channel output assumes the logic state based on the selected default option. Default is High for ISO774x and Low for ISO774x with F suffix.
When VCCI transitions from unpowered to powered-up, a channel output assumes the logic state of the input.
When VCCI transitions from powered-up to unpowered, channel output assumes the selected default state.
XPDXXUndeterminedWhen VCCO is unpowered, a channel output is undetermined(2).
When VCCO transitions from unpowered to powered-up, a channel output assumes the logic state of the input.
VCCI = Input-side VCC; VCCO = Output-side VCC; PU = Powered up (VCC ≥ 2.25 V); PD = Powered down (VCC ≤ 1.7 V); X = Irrelevant; H = High level; L = Low level ; Z = High Impedance
The outputs are in undetermined state when 1.7 V < VCCI, VCCO < 2.25 V.
A strongly driven input signal can weakly power the floating VCC through an internal protection diode and cause undetermined output.

Device I/O Schematics

ISO7740 ISO7741 ISO7742 device_IO_sllses0.gif Figure 21. Device I/O Schematics