SNVS872D August   2012  – August 2018 LMZ21700

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Efficiency for VIN = 12 V
  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 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
      1. 7.2.1 Package Construction
    3. 7.3 Feature Description
      1. 7.3.1 Input Undervoltage Lockout
      2. 7.3.2 Enable Input (EN)
      3. 7.3.3 Soft-Start and Tracking Function (SS)
      4. 7.3.4 Power Good Function (PG)
      5. 7.3.5 Output Voltage Setting
      6. 7.3.6 Output Current Limit and Output Short Circuit Protection
      7. 7.3.7 Thermal Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Mode Operation
      2. 7.4.2 PSM Operation
  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 Input Capacitor (CIN)
        3. 8.2.2.3 Output Capacitor (COUT)
        4. 8.2.2.4 Softstart Capacitor (CSS)
        5. 8.2.2.5 Power Good Resistor (RPG)
        6. 8.2.2.6 Feedback Resistors (RFBB and RFBT)
      3. 8.2.3 Application Curves
        1. 8.2.3.1 VOUT = 1.2 V
        2. 8.2.3.2 VOUT = 1.8 V
        3. 8.2.3.3 VOUT = 2.5 V
        4. 8.2.3.4 VOUT = 3.3 V
        5. 8.2.3.5 VOUT = 5.0 V
    3. 8.3 Do's and Don'ts
  9. 9 Power Supply Recommendations
    1. 9.1 Voltage Range
    2. 9.2 Current Capability
    3. 9.3 Input Connection
      1. 9.3.1 Voltage Drops
      2. 9.3.2 Stability
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Minimize the High di/dt Loop Area
      2. 10.1.2 Protect the Sensitive Nodes in the Circuit
      3. 10.1.3 Provide Thermal Path and Shielding
    2. 10.2 Layout Example
      1. 10.2.1 High Density Layout Example for Space Constrained Applications
        1. 10.2.1.1 35-mm² Solution Size (Single Sided)
  11. 11Device and Documentation Support
    1. 11.1 Device Support
    2. 11.2 Development Support
      1. 11.2.1 Custom Design With WEBENCH® Tools
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Tape and Reel Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • SIL|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.1 Overview

The LMZ21700 Nano Module is an easy-to-use step-down DC/DC solution capable of driving up to 650-mA load in space-constrained applications. Only an input capacitor, an output capacitor, a soft-start capacitor, and two resistors are required for basic operation. The Nano Module comes in 8-pin DFN footprint package with an integrated inductor. The LMZ21700 architecture is based on DCS-Control™ (direct control with seamless transition into power save mode). This architecture combines the fast transient response and stability of hysteretic type converters along with the accurate DC output regulation of voltage mode and current mode regulators.

The LMZ21700 architecture uses pulse width modulation (PWM) mode for medium and heavy load requirements and Power Save Mode (PSM) at light loads for high efficiency. In PWM mode the switching frequency is controlled over the input voltage range. The value depends on the output voltage setting and is typically reduced at low output voltages to achieve higher efficiency. In PSM the switching frequency decreases linearly with the load current. Since the architecture of the device supports both operation modes (PWM and PSM) in a single circuit building block, the transition between the modes of operation is seamless with minimal effect on the output voltage.