SLUU232A September   2005  – January 2022 TPS40190

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Description
    2. 1.2 Applications
    3. 1.3 Features
  3. 2TPS40190EVM-001 Electrical Performance Specifications
  4. 3Schematic
    1. 3.1 Adjusting Output Voltage (R1)
    2. 3.2 Adjusting Short Circuit Protection (R6)
    3. 3.3 Disable (TP1 and SW1)
  5. 4Test Setup
    1. 4.1 Equipment
      1. 4.1.1 Voltage Source (V12V_IN)
      2. 4.1.2 Meters
      3. 4.1.3 Loads (LOAD1)
      4. 4.1.4 Oscilloscope
      5. 4.1.5 Recommended Wire Gauge
      6. 4.1.6 Other
    2. 4.2 Equipment Setup
      1. 4.2.1 Procedure
      2. 4.2.2 Diagram
    3. 4.3 Start-Up/Shutdown Procedure
    4. 4.4 Control Loop Gain and Phase Measurement Procedure
    5. 4.5 Equipment Shutdown
  6. 5TPS40190EVM Typical Performance Data and Characteristic Curves
    1. 5.1 Efficiency
    2. 5.2 Line and Load Regulation
  7. 6EVM Assembly Drawings and Layout
  8. 7List of Materials
  9. 8Revision History

3.2 Adjusting Short Circuit Protection (R6)

The TPS40190 uses a selectable current limit for short circuit protection. The current limit is selected from three levels by placing a resistor at R6. The TPS40190 compares the voltage drop across the high-side FET (VDD to SW) to an internal reference voltage selected during start-up. The voltage levels are shown in Table 3-2.

Table 3-2 Adjusting VSCP with R6
VSCP R6
160 mV 3.9 k
320 mV OPEN
420 mV 12 k

The current before declaring short circuit protection can be determined by dividing the VSCP by the RDS(ON) of the high-side FET (Q2).