SNVSCQ9 November   2025 LM68425-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Device Comparison Table
  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 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 Output Voltage Selection
      2. 7.3.2 EN Pin and Use as VIN UVLO
      3. 7.3.3 Mode Selection
        1. 7.3.3.1 MODE/SYNC/TEMP Pin Uses for Synchronization
        2. 7.3.3.2 Clock Locking
      4. 7.3.4 Adjustable Switching Frequency
      5. 7.3.5 Dual Random Spread Spectrum (DRSS)
      6. 7.3.6 Internal LDO, VCC UVLO, and BIAS Input
      7. 7.3.7 Bootstrap Voltage (BST Pin)
      8. 7.3.8 Soft Start and Recovery From Dropout
      9. 7.3.9 Safety Features
        1. 7.3.9.1 Power-Good Monitor
        2. 7.3.9.2 Redundant VOUT Monitor
        3. 7.3.9.3 Fault Output
        4. 7.3.9.4 Voltage Reference Monitor
        5. 7.3.9.5 Start-Up Diagnostics
        6. 7.3.9.6 Overcurrent and Short-Circuit Protection
        7. 7.3.9.7 Hiccup
        8. 7.3.9.8 Thermal Shutdown
        9. 7.3.9.9 Redundant Temperature Sensor
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
        1. 7.4.2.1 Peak Current Mode Operation
        2. 7.4.2.2 Auto Mode Operation
          1. 7.4.2.2.1 Diode Emulation
        3. 7.4.2.3 FPWM Mode Operation
        4. 7.4.2.4 Dropout
        5. 7.4.2.5 Recovery from Dropout
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Choosing the Switching Frequency
        3. 8.2.2.3 FB for Adjustable or Fixed Output Voltage Mode
        4. 8.2.2.4 Inductor Selection
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Input Capacitor Selection
        7. 8.2.2.7 CBOOT
        8. 8.2.2.8 External UVLO
        9. 8.2.2.9 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Ground and Thermal Considerations
      2. 8.5.2 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

8.2.3 Application Curves

Unless otherwise specified the following conditions apply: VIN = 24V, Fixed output voltage mode, BIAS connected to VOUT, TA = 25°C. All data taken on standard EVM. See Table 8-3 for BOM. See Figure 8-29 and Figure 8-30 for typical EMI filters. Typical system specifications can be found in Table 8-4.

LM68415-Q1 LM68425-Q1 LM6x425 Efficiency - Auto Mode
LM6x425 VOUT = 5V 400kHz
Figure 8-5 LM6x425 Efficiency - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Line and Load Regulation - Auto Mode
LM6xx25 VOUT = 5V 400kHz
Figure 8-7 LM6xx25 Line and Load Regulation - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Line and Load Regulation - Auto Mode
LM6x625 VOUT = 5V 2200kHz
Figure 8-9 LM6xx25 Line and Load Regulation - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Efficiency - Auto Mode
LM6xx25 VOUT = 3.3V 1000kHz
Figure 8-11 LM6xx25 Efficiency - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Efficiency - Auto Mode
LM6xx25 VOUT = 5V 1000kHz
Figure 8-13 LM6xx25 Efficiency - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Switching Frequency vs Load Current
LM6xx25 VIN = 24V 2200kHz Auto
Figure 8-15 LM6xx25 Switching Frequency vs Load Current
LM68415-Q1 LM68425-Q1 LM6xx25 Switching Frequency vs Input Voltage
LM6xx25 VOUT = 5V 2200kHz FPWM
Figure 8-17 LM6xx25 Switching Frequency vs Input Voltage
LM68415-Q1 LM68425-Q1 Input Supply Current - Auto Mode
LM6xx25 VOUT = 5V L = 2.2μH VIN = 24V
Figure 8-19 Input Supply Current - Auto Mode
LM68415-Q1 LM68425-Q1 Typical Switching Waveforms - LM6xx25 - FPWM
VIN = 24V VOUT = 5V IOUT = 2.5A 2200kHz
Figure 8-21 Typical Switching Waveforms - LM6xx25 - FPWM
LM68415-Q1 LM68425-Q1 Start-Up - Auto
VIN = 24V VOUT = 5V IOUT =1mA 2200kHz
Figure 8-23 Start-Up - Auto
LM68415-Q1 LM68425-Q1 Output Short Circuit and Recovery - Auto
VIN = 24V VOUT = 5V IOUT = 0A 2200kHz
Figure 8-25 Output Short Circuit and Recovery - Auto
LM68415-Q1 LM68425-Q1 MODE Change Transient
VIN = 24V VOUT = 5V IOUT = 1mA 2200kHz
Figure 8-27 MODE Change Transient
LM68415-Q1 LM68425-Q1 LM6x425 Efficiency - Auto Mode
LM6x425 VOUT = 3.3V 400kHz
Figure 8-6 LM6x425 Efficiency - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Line and Load Regulation - Auto Mode
LM6xx25 VOUT = 3.3V 400kHz
Figure 8-8 LM6xx25 Line and Load Regulation - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Line and Load Regulation - Auto Mode
LM6xx25 VOUT = 3.3V 2200kHz
Figure 8-10 LM6xx25 Line and Load Regulation - Auto Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Efficiency - FPWM Mode
LM6xx25 VOUT = 3.3V 1000kHz
Figure 8-12 LM6xx25 Efficiency - FPWM Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Efficiency - FPWM Mode
LM6xx25 VOUT = 5V 1000kHz
Figure 8-14 LM6xx25 Efficiency - FPWM Mode
LM68415-Q1 LM68425-Q1 LM6xx25 Switching Frequency vs Input Voltage
LM6xx25 VOUT = 3.3V 2200kHz FPWM
Figure 8-16 LM6xx25 Switching Frequency vs Input Voltage
LM68415-Q1 LM68425-Q1 Input Supply Current - Auto Mode
LM6xx25 VOUT = 3.3V L = 2.2μH VIN = 24V
Figure 8-18 Input Supply Current - Auto Mode
LM68415-Q1 LM68425-Q1 No Load Input Supply Current - Auto Mode
LM6xx25 IOUT = 0A L = 2.2μH
Figure 8-20 No Load Input Supply Current - Auto Mode
LM68415-Q1 LM68425-Q1 Typical Switching Waveforms - LM6xx25 - Auto
VIN = 24V VOUT = 5V IOUT = 0.1A 2200kHz
Figure 8-22 Typical Switching Waveforms - LM6xx25 - Auto
LM68415-Q1 LM68425-Q1 Start-Up, Shutdown - FPWM
VIN = 24V VOUT = 5V IOUT = 3.5A 2200kHz
Figure 8-24 Start-Up, Shutdown - FPWM
LM68415-Q1 LM68425-Q1 Current Limit Transient
VIN = 24V VOUT = 5V Auto 2200kHz
Figure 8-26 Current Limit Transient
LM68415-Q1 LM68425-Q1 Dropout Transient and Recovery
VIN = 24V VOUT = 5V IOUT = 1A 2200kHz
Figure 8-28 Dropout Transient and Recovery
Table 8-3 BOM for Application Curve Data
DEVICE OUTPUT VOLTAGE SWITCHING FREQUENCY INDUCTOR INDUCTOR D.C.R. COUT AT VOUT (FOR TRANSIENT TESTS)
LM6x25 5V 400kHz 10μH 0.03Ω
LM6x625 5V 2200kHz 2.2μH 0.02Ω
LM6x625 3.3V 400kHz 10μH 0.03Ω
LM6x625 3.3V 2200kHz 2.2μH 0.02Ω
LM68415-Q1 LM68425-Q1 EMI Input Filter for 2200kHz Figure 8-29 EMI Input Filter for 2200kHz
LM68415-Q1 LM68425-Q1 EMI Input Filter for 400kHz Figure 8-30 EMI Input Filter for 400kHz

The data in the following table applies only to the typical applications circuit, with nominal component values. Specifications in the typical (TYP) column apply to TJ= 25°C only. Specifications in the minimum (MIN) and maximum (MAX) columns apply to the case of typical components over the temperature range of TJ = –40°C to 150°C. These specifications are not specified by production testing.

Table 8-4 Typical System Specifications
PARAMETRS TEST CONDITIONS MIN TYP MAX UNITS
Isupply Input supply current Vin = 24V, Vout = 3.3V, Iout = 0A, LM65635, 2.2MHz 2.4 μA
Vout Vout = 5V Vin = 7V to 40V, Iout = 0A to full load, FPWM –1.5% +1.5%
Vout = 5V Vin = 7V to 40V, Iout = 0A to full load, AUTO –1.5% +2.5%
Vout Vout = 3.3V Vin = 5V to 40V, Iout = 0A to full load, FPWM –1.5% +1.5%
Vout = 3.3V Vin = 5V to 40V, Iout = 0A to full load, AUTO –1.5% +2.5%
η Peak efficiency Vin = 12V, Vout = 5V, Iout = 1.5A, LM65645, 400kHz 95%
Vin = 24V, Vout = 5V, Iout = 1.5A, LM65645, 400kHz 93.6%