SNVS402I February   2006  – May 2021 LM5009

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Control Circuit Overview
      2. 7.3.2 High Voltage Startup Regulator
      3. 7.3.3 Regulation Comparator
      4. 7.3.4 Overvoltage Comparator
      5. 7.3.5 On-Time Generator
      6. 7.3.6 Current Limit
      7. 7.3.7 N-Channel Buck Switch and Driver
      8. 7.3.8 Thermal Protection
    4. 7.4 Device Functional Modes
  8. 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 Output Resistor Divider Selection
        2. 8.2.2.2 Frequency Selection
        3. 8.2.2.3 Inductor Selection
        4. 8.2.2.4 VCC and Bootstrap Capacitor
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Current Limit Off-Timer Setting
        7. 8.2.2.7 Rectifier Diode Selection
        8. 8.2.2.8 Input Capacitor Selection
        9. 8.2.2.9 Ripple Configuration
      3. 8.2.3 Application Curves
    3. 8.3 Do's and Don'ts
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

5 Pin Configuration and Functions

GUID-E860B18D-34B5-4DFF-A600-21007F4A34B7-low.gifFigure 5-1 DGK, NGU Packages8-Pin VSSOP, WSONTop View
Table 5-1 Pin Functions
PINI/ODESCRIPTION
NAMENO.
BST2IBoost pin. An external capacitor is required between the BST and SW pins. A 0.022-µF ceramic capacitor is recommended. An internal diode charges the capacitor from VCC.
EP——Exposed pad (WSON package only). Exposed metal pad on the underside of the device. Connecting this pad to the PC board ground plane is recommended to aid in heat dissipation.
FB5IFeedback input from regulated output. This pin is connected to the inverting input of the internal regulation comparator. The regulation threshold is 2.5 V.
RCL3ICurrent limit off-time set pin. A resistor between this pin and RTN sets the off-time when current limit is detected. The off-time is preset to 35 µs if FB = 0 V.
RON/SD6IOn-time set pin. A resistor between this pin and VIN sets the switch on-time as a function of VIN. The minimum recommended on-time is 250 ns at the maximum input voltage. This pin can be used for remote shutdown.
RTN4—Ground pin. Ground for the entire circuit.
SW1OSwitching output. Power switching output. Connect to the inductor, recirculating diode, and bootstrap capacitor.
VCC7OOutput from the internal high-voltage startup regulator. Regulated at 7.0 V. If an auxiliary voltage is available to raise the voltage on this pin above the regulation set point (7 V), the internal series pass regulator shuts down, reducing the device power dissipation. Do not exceed 14 V. This voltage provides gate drive power for the internal buck switch. An internal diode is provided between this pin and the BST pin. A local 0.1-µF decoupling capacitor is required.
VIN8IInput voltage. Recommended operating range: 9.5 V to 95 V.