SBASAJ8A June   2022  – August 2022 AMC22C12

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  Power Ratings
    6. 6.6  Insulation Specifications 
    7. 6.7  Safety-Related Certifications 
    8. 6.8  Safety Limiting Values 
    9. 6.9  Electrical Characteristics
    10. 6.10 Switching Characteristics 
    11. 6.11 Timing Diagrams
    12. 6.12 Insulation Characteristics Curves
    13. 6.13 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Analog Input
      2. 7.3.2 Reference Input
      3. 7.3.3 Isolation Channel Signal Transmission
      4. 7.3.4 Open-Drain Digital Output
        1. 7.3.4.1 Transparent Output Mode
        2. 7.3.4.2 Latch Output Mode
      5. 7.3.5 Power-Up and Power-Down Behavior
      6. 7.3.6 VDD1 Brownout and Power-Loss Behavior
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Overcurrent Detection
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
      2. 8.2.2 Overvoltage Detection
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
      2. 8.5.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  10. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Mechanical Data

Package Options

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

7.3.2 Reference Input

The voltage on the REF pin determines the trip threshold of the window comparator. The internal precision current source forces a 100-μA current through an external resistor connected from the REF pin to GND1. The resulting voltage across the resistor (VREF) equals the magnitude of the positive and negative trip thresholds, see Figure 7-1. Place a 100-nF capacitor parallel to the resistor to filter the reference voltage. This capacitor must be charged by the 100-μA current source during power-up and the charging time may exceed the high-side blanking time (tHS,BLK). In this case, as shown in Figure 7-2, the comparator may output an incorrect state after the high-side blanking time has expired until VREF reaches the final value. See the Section 7.3.5 section for more details on power-up behavior.

Figure 7-2 Output Behavior for Long Settling Times of the Reference Voltage

The voltage on the REF pin also determines the functionality of the negative comparator (Cmp1) and the hysteresis of the positive comparator (Cmp0) shown in the Section 7.2. If VREF exceeds the VMSEL threshold defined in the Electrical Characteristics table, Cmp1 is disabled and the hysteresis of Cmp0 is increased from 4 mV (typical) to 25 mV. Positive-comparator mode is intended for voltage-monitoring applications that require higher input voltages and higher noise immunity.

The reference pin can be driven by an external voltage source to change the comparator thresholds during operation. However, do not drive VREF dynamically across the VMSEL threshold during normal operation because doing so changes the hysteresis of the Cmp0 comparator and can lead to unintentional switching of the output.

Figure 7-3 shows a mode selection timing diagram.

Figure 7-3 Mode Selection