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

3.1 Adjusting Output Voltage (R1)

The regulated output voltage can be adjusted within a limited range by changing the ground resistor in the feedback resistor divider (R1). The output voltage is given by Equation 1.

Equation 1. VOUT= VVREF × R5+R1R1

where

  • VVREF = 0.591 V
  • R5 = 10 kΩ

Table 3-1 contains common values for R1 to generate popular output voltages. The TPS40190EVM-001 is stable through these output voltages but the efficiency can suffer as the power stage is optimized for the 1.5-V output.

Table 3-1 Adjusting VOUT with R1
VOUT R1
3.3 V(1) 2.15 k
2.5 V(1) 3.09 k
2.25 V 3.57 k
2.0 V 4.22 k
1.8 V 4.87 k
1.5 V 6.49 k
1.2 V 9.76 k
(1) For output voltages greater than 2.5 V, change C11 to 330 μF, 4 V or higher PosCAP.