SLLS918D July   2008  – November 2024 ISO721-Q1 , ISO722-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  Recommended Operating Conditions
    3. 6.3  Thermal Information
    4. 6.4  Power Ratings
    5. 6.5  Insulation Specifications
    6. 6.6  Safety-Related Certifications
    7. 6.7  Safety Limiting Values
    8. 6.8  Electrical Characteristics: VCC1 and VCC2 5-V Operation
    9. 6.9  Electrical Characteristics: VCC1 and VCC2 at 3.3-V Operation
    10. 6.10 Electrical Characteristics: VCC1 at 3.3-V, VCC2 at 5-V Operation
    11. 6.11 Electrical Characteristics: VCC1 at 5-V, VCC2 at 3.3-V Operation
    12. 6.12 Switching Characteristics: VCC1 and VCC2 5-V Operation
    13. 6.13 Switching Characteristics: VCC1 and VCC2 at 3.3-V Operation
    14. 6.14 Switching Characteristics: VCC1 at 3.3-V, VCC2 at 5-V Operation
    15. 6.15 Switching Characteristics: VCC1 at 5-V, VCC2 at 3.3-V Operation
    16. 6.16 Typical Characteristics
    17. 6.17 Insulation Characteristics Curves
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Device Functional Modes
      1. 8.3.1 Device I/O Schematic
  10. 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. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 PCB Material
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

3 Description

The ISO721-Q1 and ISO722-Q1 devices are digital isolators with a logic input and output buffer separated by a silicon dioxide (SiO2) insulation barrier. This barrier provides galvanic isolation of up to 4000 VPK per VDE 0884-17. Used in conjunction with isolated power supplies, these devices prevent noise currents on a data bus or other circuits from entering the local ground, and interfering with or damaging sensitive circuitry.

A binary input signal is conditioned, translated to a balanced signal, then differentiated by the capacitive isolation barrier. Across the isolation barrier, a differential comparator receives the logic transition information, then sets or resets a flip-flop and the output circuit accordingly. A periodic update pulse is sent across the barrier to provide the proper dc level of the output.

If this dc-refresh pulse is not received for more than 4μs, the input is assumed to be unpowered or not being actively driven, and the failsafe circuit drives the output to a logic-high state.

These devices require two supply voltages of 3.3V, 5V, or any combination. All inputs are 5V tolerant when supplied from a 3.3V supply and all outputs are 4mA CMOS.

The ISO722-Q1 devices include an active-low output enable that when driven to a high logic level, places the output in a high-impedance state and turns off internal bias circuitry to conserve power.

The ISO721-Q1 and ISO722-Q1 devices have TTL input thresholds and a noise filter at the input that prevent transient pulses of up to 2 ns in duration from being passed to the output of the device.

The ISO721-Q1 and ISO722-Q1 devices are characterized for operation over the ambient temperature range of –40°C to +125°C.

Package Information
PART NUMBER(1) PACKAGE BODY SIZE (NOM) PACKAGE SIZE(2)
ISO721-Q1 D (SOIC, 8) 4.90mm × 3.91mm 4.9mm × 6mm
ISO722-Q1
(1) For all available packages, see the orderable addendum at the end of the data sheet.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.
ISO721-Q1 ISO722-Q1 Simplified Schematic Simplified Schematic