SNVS617H April   2009  – November 2014 LM25011 , LM25011-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings: LM25011
    3. 6.3 Handling Ratings: LM25011-Q1
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Thermal Information
    6. 6.6 Electrical Characteristics
    7. 6.7 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 On-Time Timer
      3. 7.3.3 Current Limit
      4. 7.3.4 Ripple Requirements
      5. 7.3.5 N-Channel Buck Switch and Driver
      6. 7.3.6 Soft-Start
      7. 7.3.7 Power Good Output (PGD)
      8. 7.3.8 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Function
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 LM25011 Example Circuit
        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 External Components
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Output Ripple Control
        1. 8.2.2.1 Option A: Lowest Cost Configuration
        2. 8.2.2.2 Option B: Intermediate VOUT Ripple Configuration
        3. 8.2.2.3 Option C: Minimum VOUT Ripple Configuration
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Power Dissipation
  11. 11Device and Documentation Support
    1. 11.1 Custom Design with WEBENCH Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Related Links
    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

10-Pin
HVSSOP Package
Top View
LM25011 LM25011-Q1 LM25011A LM25011A-Q1 30094602.gif

Pin Functions

PIN I/O DESCRIPTION APPLICATION INFORMATION
NUMBER NAME
1 VIN I Input supply voltage Operating input range is 6 V to 42 V. Transient capability is 45 V. A low ESR capacitor must be placed as close as possible to the VIN and SGND pins.
2 RT I On-time Control An external resistor from VIN to this pin sets the buck switch on-time and the switching frequency.
3 PGD – Power Good Logic output indicates when the voltage at the FB pin has increased to above 95% of the internal reference voltage. Hysteresis is provided. An external pull-up resistor to a voltage less than 7 V is required.
4 SS I Soft-Start An internal current source charges an external capacitor to provide the soft-start function.
5 SGND Signal Ground Ground for all internal circuitry other than the current limit sense circuit.
6 FB I Feedback Internally connected to the regulation comparator. The regulation level is 2.51 V.
7 CSG – Current Sense Ground Ground connection for the current limit sensing circuit. Connect to ground and to the current sense resistor.
8 CS I Current sense Connect to the current sense resistor and the anode of the free-wheeling diode.
9 SW O Switching Node Internally connected to the buck switch source. Connect to the external inductor, cathode of the free-wheeling diode, and bootstrap capacitor.
10 BST I Bootstrap capacitor connection of the buck switch gate driver. Connect a 0.1-µF capacitor from SW to this pin. The capacitor is charged during the buck switch off-time via an internal diode.
- EP – Exposed Pad Exposed pad on the underside of the package. This pad should be soldered to the PC board ground plane to aid in heat dissipation.