SBOSAF3 November   2023 TMCS1126

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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 Insulation Specifications
    6. 6.6 Electrical Characteristics
  8. 7 Parameter Measurement Information
    1. 7.1 Accuracy Parameters
      1. 7.1.1 Sensitivity Error
      2. 7.1.2 Offset Error and Offset Error Drift
      3. 7.1.3 Nonlinearity Error
      4. 7.1.4 Power Supply Rejection Ratio
      5. 7.1.5 Common-Mode Rejection Ratio
      6. 7.1.6 External Magnetic Field Errors
    2. 7.2 Transient Response Parameters
      1. 7.2.1 CMTI, Common-Mode Transient Immunity
    3. 7.3 Safe Operating Area
      1. 7.3.1 Continuous DC or Sinusoidal AC Current
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Current Input
      2. 8.3.2 Input Isolation
      3. 8.3.3 Ambient Field Rejection
      4. 8.3.4 High-Precision Signal Chain
        1. 8.3.4.1 Temperature Stability
        2. 8.3.4.2 Lifetime and Environmental Stability
      5. 8.3.5 Internal Reference Voltage
      6. 8.3.6 Current-Sensing Measurable Ranges
      7. 8.3.7 Overcurrent Detection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Down Behavior
  10. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Total Error Calculation Examples
        1. 9.1.1.1 Room-Temperature Error Calculations
        2. 9.1.1.2 Full-Temperature Range Error Calculations
    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
      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
    1. 12.1 Package Option Addendum
    2. 12.2 Tape and Reel Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DVG|10
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.7 Overcurrent Detection

In addition to a fast precision analog signal response, the TMCS1126 also offers a fast digital overcurrent response. The Overcurrent Detection (OCD) circuit provides a comparator output that can be used to trigger a warning or system shutdown to prevent damage that may occur in the event of excessive current flow caused by shorts circuits, motor stalls, or other system conditions. This fast digital response can be configured on both bidirectional and unidirectional devices to trip either inside or outside the analog measurement range. When set up to trigger outside the analog measurement range, this fast digital overcurrent output OC along with the precision analog output VOUT allows the user to optimize of control-loop dynamic range.

The desired overcurrent threshold IOC is set by applying an external voltage VOC to the VOC pin according to Equation 20.

Equation 20. V O C = S × I O C 2.5

where

  • S is the device sensitivity in mV/A.
  • IOC is the desired overcurrent threshold.
  • VOC is the voltage applied that sets the overcurrent threshold.

A digital-to-analog converter (DAC) can be used to set the desired overcurrent threshold IOC, or a simple external resistor divider circuit can be used as shown in Figure 8-2. For example, to set the desired overcurrent threshold to IOC = ±50 A on the bidirectional TMCS1126A3A or TMCS1126B3A devices, or to IOC = 50 A on the unidirectional TMCS1126C3A device, resistors R1 and R2 should be sized to apply a voltage VOC = 1.5 V to the VOC pin according to Equation 20.

with

  • TMCS1126A3A, TMCS1126B3A and TMCS1126C3A device sensitivity, S = 75 mV/A.
  • Desired overcurrent threshold, IOC = 50 A.
  • Applied overcurrent threshold voltage VOC = 1.5 V.

GUID-20230504-SS0I-SKB2-JN3B-TKR79DKLJFV9-low.svg Figure 8-2 User Configurable Overcurrent Threshold

Figure 8-3 shows the overcurrent digital output OC response as active-low. When the input current exceeds ±IOC on a bidirectional device, the fast OC pin is pulled low. The input current must return to within ±IOC by more than a hysteresis current IHys before the OC pin resets back to the normal high-state.

GUID-20230426-SS0I-HHHQ-ZLNF-8NQC7KXXSQHB-low.svg Figure 8-3 Overcurrent Detection Diagram