SBASAB2A February   2022  – July 2022 AMC23C12

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

Package Options

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

8.2.2.2 Detailed Design Procedure

The voltage divider consisting of R1, R2, and RSNS is sized such that the voltage drop across RSNS equals the linear full-scale input voltage (2 V) of the AMC1311B at the maximum DC-link voltage that is of interest for linear sensing (450 V). Therefore, the voltage drop across RSNS at the overvoltage condition is 480 V / 450 V × 2 V = 2.133 V. This value is the target value for the reference voltage (VREF) of the AMC23C12.

VREF is determined by the external resistor R1 and the internal 100-μA current source of the AMC23C12. R1 is calculated as (VTRIP – VHYS) / IREF = (2133 mV – 25 mV) / 100 μA = 21.08 kΩ. The closest value in the E192 series is 21.0 kΩ. The comparator hysteresis voltage (VHYS) is subtracted from VTRIP because the comparator trips at VREF + VHYS, see Figure 7-1. The hysteresis value is 25 mV because the reference voltage is greater than 550 mV, as explained in the Section 7.3.2 section.

Table 8-4 summarizes the key parameters of the design.

Table 8-4 Overvoltage and Undervoltage Detection Design Example
PARAMETER VALUE
Reference resistor value (R1) 21.0 kΩ
Reference capacitor value (C5) 100 nF
Reference voltage 2100 mV
Reference voltage settling time (to 90% of final value) 4.85 ms
Overvoltage trip threshold (rising) 478 V
Overvoltage trip threshold (falling) 472 V