JAJSDP3C March   2016  – June 2018 LMZ34202

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      アプリケーション概略図
      2.      効率と出力電流との関係
  4. 4 改訂履歴
  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 Switching Characteristics
    7. 6.7 Typical Characteristics
    8. 6.8 Typical Characteristics (Thermal Derating)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Switching Frequency (RT)
      3. 7.3.3  Recommended Operating Range
      4. 7.3.4  Synchronization (CLK)
      5. 7.3.5  Output Capacitor Selection
      6. 7.3.6  VERSA-COMP Pin Configurations
      7. 7.3.7  Input Capacitor Selection
      8. 7.3.8  Output On/Off Inhibit (INH/UVLO)
      9. 7.3.9  Under Voltage Lockout (UVLO)
      10. 7.3.10 Remote Sense
      11. 7.3.11 VBSEL
      12. 7.3.12 Soft-Start (SS/TR)
      13. 7.3.13 Power Good (PWRGD) and Pull-up (PWRGD_PU)
      14. 7.3.14 Overcurrent Protection
      15. 7.3.15 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Light Load Operation
      3. 7.4.3 Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Minimum External Component Application
        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 Output Voltage Set-Point
          3. 8.2.1.2.3 RT and RTSEL
          4. 8.2.1.2.4 VERSA-COMP
          5. 8.2.1.2.5 VBSEL
          6. 8.2.1.2.6 Input Capacitors
          7. 8.2.1.2.7 Output Capacitors
        3. 8.2.1.3 Application Curves
      2. 8.2.2 INH Control Application
        1. 8.2.2.1 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Switching Frequency
        2. 8.2.3.2 Power Good
        3. 8.2.3.3 Inhibit Control
        4. 8.2.3.4 VERSA-COMP
        5. 8.2.3.5 VBSEL
        6. 8.2.3.6 Soft-Start Capacitors
        7. 8.2.3.7 Input Capacitors
        8. 8.2.3.8 Output Capacitors
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 EMI
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 開発サポート
        1. 11.1.1.1 WEBENCH®ツールによるカスタム設計
      2. 11.1.2 デベロッパー・ネットワークの製品に関する免責事項
    2. 11.2 ドキュメントの更新通知を受け取る方法
    3. 11.3 コミュニティ・リソース
    4. 11.4 商標
    5. 11.5 静電気放電に関する注意事項
    6. 11.6 Glossary
  12. 12メカニカル、パッケージ、および注文情報

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

7.3.2 Switching Frequency (RT)

The switching frequency range of the LMZ34202 is 200 kHz to 1 MHz. Not all PVIN, VOUT, and IOUT conditions can be set to all of the frequencies in this range. See Recommended Operating Range for the allowable operating ranges. The switching frequency can easily be set one of three ways. First, leaving the RT pin (pin 9) and RTSEL pin (pin 10) floating (OPEN) allows operation at the default switching frequency of 500 kHz. Also, connecting the RTSEL pin to AGND while floating the RT pin, sets the switching frequency to 1 MHz. The option is also available to set the switching frequency to any frequency in the range of 200 kHz to 1 MHz, by connecting a resistor (RRT) between the RT pin and AGND, while floating the RTSEL pin. See Table 3 for standard resistor values for setting the switching frequency or use Equation 2 to calculate RRT for other switching frequencies.

Table 3. Switching Frequency RRT Values

Switching Frequency RRT (kΩ)
250 kHz 158
500 kHz 78.7 or (RT pin OPEN, RTSEL pin OPEN)
750 kHz 53.6
1 MHz 38.3 or (RT pin OPEN, RTSEL pin to AGND)
Equation 2. LMZ34202 Rrt_Equation.gif