SLVSG43A December   2023  – November 2024 TPSI3100-Q1

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. 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 Insulation Characteristic Curves
    12. 6.12 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Transmission of the Enable State
      2. 8.3.2 Power Transmission
      3. 8.3.3 Gate Driver
      4. 8.3.4 Chip Enable (CE)
      5. 8.3.5 Comparators
        1. 8.3.5.1 Fault Comparator
        2. 8.3.5.2 Alarm Comparator
        3. 8.3.5.3 Comparator De-glitch
      6. 8.3.6 VDDP, VDDH, and VDDM Undervoltage Lockout (UVLO)
      7. 8.3.7 Keep-Off Circuitry
      8. 8.3.8 Thermal Shutdown
    4. 8.4 Device Operation
    5. 8.5 Device Functional Modes
  10. 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
        1. 9.2.2.1 CDIV1, CDIV2 Capacitance
        2. 9.2.2.2 Start-up Time and Recovery Time
        3. 9.2.2.3 RSHUNT, R1, and R2 Selection
        4. 9.2.2.4 Overcurrent Fault Error
        5. 9.2.2.5 Overcurrent Alarm Error
        6. 9.2.2.6 VDDP Capacitance, CVDDP
      3. 9.2.3 Application Curves
    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 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DVX|16
Thermal pad, mechanical data (Package|Pins)
Orderable Information

RSHUNT, R1, and R2 Selection

The TPSI3100-Q1 has an internal nominal voltage reference (VREF) of 0.31V. This reference is shared by the fault and alarm comparator negative inputs.

The alarm event should be detected when the load current, ILOAD, reaches 4A nominal. The required shunt resistor can be computed as:

Equation 6. R S H U N T = V R E F I L O A D = 0.31 V 4 A   = 77.5 m Ω

For this design, RSHUNT = 75mΩ, is used. From this, the nominal alarm current, IALM, detected can be computed:

Equation 7. I A L M = V R E F R S H U N T = 0.31 V 75 m Ω = 4.13 A

The fault event should be detected when the load current, ILOAD, reaches 8A nominal. This corresponds to a voltage drop across the shunt resistor of VSENSE_FLT:

Equation 8. V S E N S E _ F L T = R S H U N T × I O C P = 75 m Ω × 8 A = 600 m V

Since the fault comparator threshold of the TPSI3100-Q1 is also the nominal voltage reference (VREF) of 0.31V, a resistor divider is required to scale the VSENSE_FLT voltage to the comparator input threshold (VREF). The divider ratio (DIV) required can be calculated from:

Equation 9. D I V = V R E F V S E N S E _ F L T = 0.31 V 0.6 V = 0.517
Equation 10. D I V = R 2 R 1 + R 2

For this design, the divider (DIV) was selected as 0.5. Therefore, R1 = R2. This leads to a nominal overcurrent of:

Equation 11. I O C P = V R E F D I V × R S H U N T = 0.31 V 0.5 × 75 m Ω = 8.27 A

The power dissipated in the shunt resistor while remaining at the alarm condition can be computed as:

Equation 12. P S H U N T _ A L M = I A L M 2 × R S H U N T = ( 4.13 A ) 2 × 75 m Ω = 1.28 W

Similarly, the power dissipated in the shunt resistor at the overcurrent condition can be computed as:

Equation 13. P S H U N T _ O C P = I O C P 2 × R S H U N T = ( 8.27 A ) 2 × 75 m Ω = 5.13 W

A power rating for the shunt resistor should be chosen that is sufficient to handle these power conditions compared to those experienced during normal loading. If the system can take necessary action in a timely manner upon an alarm condition, a 2W power rated resistor is deemed sufficient. An overcurrent event causes the driver to be disabled quickly by the TPSI3100-Q1, and the overload current exists for short duration. A more conservative approach is to select a 5W power rated resistor.