SLVSHP0 July   2024 TLVM14404 , TLVM14406

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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 Electrical Characteristics
    6. 6.6 System Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Input Voltage Range (VIN1, VIN2)
      2. 7.3.2  Enable EN Pin and Use as VIN UVLO
      3. 7.3.3  CONFIG Device Configuration Pin
      4. 7.3.4  Adjustable Switching Frequency
      5. 7.3.5  Adjustable Output Voltage (FB)
      6. 7.3.6  Input Capacitors
      7. 7.3.7  Output Capacitors
      8. 7.3.8  Power-Good Output Voltage Monitoring
      9. 7.3.9  Bias Supply Regulator (VCC, VOSNS)
      10. 7.3.10 Overcurrent Protection (OCP)
      11. 7.3.11 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
  9. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1 – High-efficiency, Dual Output 5V at 3A, 3.3V at 3A, Synchronous Buck Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Output Voltage Setpoint
          3. 8.2.1.2.3 Switching Frequency Selection
          4. 8.2.1.2.4 Input Capacitor Selection
          5. 8.2.1.2.5 Output Capacitor Selection
          6. 8.2.1.2.6 Other Considerations
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design 2 – High-efficiency, 6A, Synchronous Buck Regulator for Industrial Applications
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Output Voltage Setpoint
          2. 8.2.2.2.2 Switching Frequency Selection
          3. 8.2.2.2.3 Input Capacitor Selection
          4. 8.2.2.2.4 Output Capacitor Selection
          5. 8.2.2.2.5 Other Connections
        3. 8.2.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Thermal Design and Layout
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
        1. 9.1.2.1 Custom Design With WEBENCH® Tools
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.3.5 Adjustable Output Voltage (FB)

The TLVM1440x has an adjustable output voltage range from 0.8V up to a maximum of 9V or slightly less than VIN, whichever is lower. Setting the output voltage requires two feedback resistors, designated as RFBT and RFBB in schematics. The reference voltage at the feedback (FB) pin is set at 0.8V with a feedback system accuracy over the full junction temperature range of ±1%. The junction temperature range for the device is –40°C to 125°C.

Calculate the value for RFBB using Equation 4 below based on a recommended value for RFBT of 100kΩ.

Equation 4. RFBBkΩ= RFBTkΩVOUT0.8-1 

Table 7-4 lists the standard resistor values for several output voltages and the recommended switching frequency range to maintain reasonable peak-to-peak inductor ripple current. This table also includes the minimum required output capacitance for each output voltage setting to maintain stability. The capacitances as listed represent effective values for ceramic capacitors derated for DC bias voltage and temperature. Furthermore, place a feedforward capacitor, CFF, in parallel with RFBT to increase the phase margin when the output capacitance is close to the minimum recommended value.

Table 7-4 Standard RFBT Values, Recommended FSW Range and Minimum COUT
VOUT (V)RFBT (kΩ) (1)RFBB (kΩ) (1) SUGGESTED FSW RANGE (kHz)COUT(min) (µF), Per Phase (EFFECTIVE)BOM(2)CFF (pF)
0.810Open300 to 7004701 × 47μF (6.3V), 1 × 470μF (2.5V)—
1.812.410300 to 10001253 × 47μF (6.3V), 1 × 22μF (6.3V)330
3.331.210500 to 130064 4 × 22μF (10V)Internal
552.310700 to 210064 4 × 22μF (10V)Internal
9105101200 to 2100403 × 22μF (16V)4.7
(1) RFBT = 100kΩ.
(2) Refer to Table 7-6 for the output capacitor list.

Note that higher feedback resistances consume less DC current. However, an upper RFBT resistor value higher than 1MΩ renders the feedback path more susceptible to noise. Higher feedback resistances generally require more careful layout of the feedback path. Make sure to locate the feedback resistors close to the FB and AGND pins, keeping the feedback trace as short as possible (and away from noisy areas of the PCB). See Layout Example guidelines for more detail.