SNVSCF0 October   2024 LM65680-Q1

ADVANCE INFORMATION  

  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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Descriptions
      1. 7.3.1  Output Voltage Selection
      2. 7.3.2  EN Pin and Use as VIN UVLO
      3. 7.3.3  Device Configuration
      4. 7.3.4  Single-Output Dual-Phase Operation
      5. 7.3.5  Mode Selection
        1. 7.3.5.1 MODE/SYNC Pin Uses for Synchronization
        2. 7.3.5.2 Clock Locking
      6. 7.3.6  Adjustable Switching Frequency
      7. 7.3.7  Dual Random Spread Spectrum (DRSS)
      8. 7.3.8  Internal LDO, VCC UVLO, and BIAS Input
      9. 7.3.9  Bootstrap Voltage (BST Pin)
      10. 7.3.10 Soft Start and Recovery From Dropout
      11. 7.3.11 Safety Features
        1. 7.3.11.1 Power-Good Monitor
        2. 7.3.11.2 Overcurrent and Short-Circuit Protection
        3. 7.3.11.3 Hiccup
        4. 7.3.11.4 Thermal Shutdown
    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
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Power Train Components
        1. 8.1.1.1 Buck Inductor
        2. 8.1.1.2 Output Capacitors
        3. 8.1.1.3 Input Capacitors
        4. 8.1.1.4 EMI Filter
      2. 8.1.2 Error Amplifier and Compensation
      3. 8.1.3 Maximum Ambient Temperature
        1. 8.1.3.1 Derating Curves
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Inductor Selection
        2. 8.2.2.2 Output Capacitors
        3. 8.2.2.3 Feed-forward Capacitor (CFF)
        4. 8.2.2.4 Input Capacitor Selection
        5. 8.2.2.5 Choosing the Switching Frequency
        6. 8.2.2.6 Setting the Output Voltage
        7. 8.2.2.7 Compensation Components
        8. 8.2.2.8 CBST
        9. 8.2.2.9 External UVLO
      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 Development Support
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
        1. 9.2.1.1 PCB Layout Resources
        2. 9.2.1.2 Thermal Design Resources
    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
    1. 11.1 Tape and Reel Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The LM656x0-Q1 are a family of stackable, automotive buck converters designed for high efficiency, high power density, and ultra-low electromagnetic interference (EMI). The converters operate over a wide input voltage range of 3V to 70V simplifying input surge protection design.

The low EMI operation is enabled with minimized loop inductance, pin-selectable SW node slew-rate control and dual-random spread spectrum (DRSS). The DRSS significantly reduces peak emissions through a combination of triangular and pseudo-random modulation while keeping output voltage ripple very low.

The current-mode control architecture with 36ns minimum on-time allows high conversion ratios at high frequencies, easy loop compensation, fast transient response, and excellent load and line regulation. Up to two converters can be set up in an interleaved mode (paralleled outputs) with accurate current sharing for supporting output current up to 16A.

Device Information
PART NUMBER(2) PACKAGE(1) OUTPUT CURRENT
LM65680-Q1 RZY (WQFN-FCRLF, 26) 8A
LM65660-Q1(3) 6A
LM65640-Q1(3) 4A
(1) For more information, see Section 11.
(3) Preview information (not Advance Information).
LM65680-Q1 Typical Application CircuitTypical Application Circuit
LM65680-Q1 Typical Efficiency VOUT = 5V, fSW = 400kHzTypical Efficiency VOUT = 5V, fSW = 400kHz