SLUU274A May   2007  – January 2022 TPS40193

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Description
    2. 1.2 Applications
    3. 1.3 Features
  3. 2TPS40193EVM-001 Electrical Performance Specifications
  4. 3Schematic
  5. 4General Configuration and Description
    1. 4.1 Adjusting Output Voltage (R7)
    2. 4.2 Adjusting Short-Circuit Protection (R9)
    3. 4.3 Disable Jumper (JP1)
    4. 4.4 Test Point Descriptions
      1. 4.4.1 Input Voltage Monitoring (TP1, TP2)
      2. 4.4.2 Power-Good (TP3, TP4, TP5)
      3. 4.4.3 Compensation and Initialization (TP6)
      4. 4.4.4 Switching Waveforms (TP7, TP8, TP9, TP10)
      5. 4.4.5 Loop Analysis (TP11, TP12, TP13, TP14)
      6. 4.4.6 Output Voltage and Monitoring (TP15, TP16)
      7. 4.4.7 Pre-Bias Input (TP17)
  6. 5Test Setup
    1. 5.1 Equipment
      1. 5.1.1 Voltage Source
      2. 5.1.2 Meters
      3. 5.1.3 Loads
      4. 5.1.4 Oscilloscope
      5. 5.1.5 Recommended Wire Gauge
      6. 5.1.6 Other
    2. 5.2 Equipment Setup
    3. 5.3 Start-Up/Shutdown Procedure
    4. 5.4 Output Ripple Voltage Measurement Procedure
    5. 5.5 Control Loop Gain and Phase Measurement Procedure
    6. 5.6 Equipment Shutdown
  7. 6TPS40193EVM-001 Typical Performance Data and Characteristic Curves
    1. 6.1 Efficiency
    2. 6.2 Line and Load Regulation
    3. 6.3 Output Voltage Ripple
    4. 6.4 Switch Node
    5. 6.5 Control Loop Bode Plot
      1. 6.5.1 Low Line (VIN = 8 V)
      2. 6.5.2 High Line (VIN = 14 V)
  8. 7EVM Assembly Drawings and Layout
  9. 8Bill of Materials
  10. 9Revision History

4.1 Adjusting Output Voltage (R7)

The regulated output voltage can be adjusted within a limited range by changing the ground resistor in the feedback resistor divider (R7). The output voltage is given by the formula shown in Equation 1:

Equation 1. GUID-039849DE-B556-47F1-A4B6-C79862154FAE-low.gif

where

  • VVREF = 0.591 V
  • R8 = 20 kΩ

Table 4-1 contains common values for R7 to generate popular output voltages. The TPS40193EVM-001 is stable through these output voltages, but efficiency may suffer because the power stage is optimized for 1.8V output.

Table 4-1 Adjusting VOUT with R7
VOUT R7 (kΩ)
3.3V 4.32
2.5V 6.19
2.25V 7.15
2.0V 8.25
1.8V 9.76
1.5V 13.0
1.2V 19.1
1.0V 28.7
0.9V 38.3

The values in Table 4-1 provide less than 1% nominal set-point error in the output voltage. If a tighter nominal value is required, R5 can be used in parallel with R7 to obtain a wider range of resistor values, using commonly available E96 resistors.