SNVSB27C June   2018  – October 2020 LMR33620-Q1

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 Timing Characteristics
    7. 6.7 System Characteristics
    8. 6.8 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 Power-Good Flag Output
      2. 7.3.2 Enable and Start-up
      3. 7.3.3 Current Limit and Short Circuit
      4. 7.3.4 Undervoltage Lockout and Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto Mode
      2. 7.4.2 Dropout
      3. 7.4.3 Minimum Switch On-Time
  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  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Choosing the Switching Frequency
        3. 8.2.2.3  Setting the Output Voltage
          1. 8.2.2.3.1 Fixed Output Voltage Option
        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  VCC
        9. 8.2.2.9  CFF Selection
        10. 8.2.2.10 External UVLO
        11. 8.2.2.11 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 What to Do and What Not to Do
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Ground and Thermal Considerations
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Support Resources
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RNX|12
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5 Pin Configuration and Functions

Figure 5-1 12-Pin VQFN RNX Package (Top View)
Table 5-1 Pin Functions
PIN TYPE DESCRIPTION
NO. NAME
1, 11 PGND G Power ground terminal. Connect to system ground and AGND. Connect to a bypass capacitor with short wide traces.
2, 10 VIN P Input supply to regulator. Connect a high-quality bypass capacitor(s) directly to this pin and PGND.
3 NC — On the VQFN package, connect the SW pin to NC on the PCB. This simplifies the connection from the CBOOT capacitor to the SW pin. This pin has no internal connection to the regulator.
4 BOOT P Boot-strap supply voltage for internal high-side driver. Connect a high-quality 100-nF capacitor from this pin to the SW pin. On the VQFN package connect the SW pin to NC on the PCB. This simplifies the connection from the CBOOT capacitor to the SW pin.
5 VCC P Internal 5-V LDO output. Used as supply to internal control circuits. Do not connect to external loads. Can be used as logic supply for power-good flag. Connect a high quality 1-µF capacitor from this pin to GND.
6 AGND G Analog ground for regulator and system. Ground reference for internal references and logic. All electrical parameters are measured with respect to this pin. Connect to system ground on PCB.
7 FB A Feedback input to regulator. Connect to tap point of feedback voltage divider. DO NOT FLOAT. DO NOT GROUND. With the fixed output voltage version, connect this input directly to VOUT near the output capacitor.
8 PG A Open drain power-good flag output. Connect to suitable voltage supply through a current limiting resistor. High = power OK, low = power bad. Flag pulls low when EN = Low. Can be left open when not used.
9 EN A Enable input to regulator. High = ON, low = OFF. Can be connected directly to VIN; DO NOT FLOAT.
12 SW P Regulator switch node. Connect to power inductor. On the VQFN package the SW pin must be connected to NC on the PCB. This simplifies the connection from the CBOOT capacitor to the SW pin.
A = Analog, P = Power, G = Ground