JAJSFM8B June   2018  – May 2019 LMZM33606

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
    1.     概略回路図
  3. 3 概要
    1.     最小のソリューション・サイズ
    2.     標準的な効率(自動モード)
  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 (VIN = 12 V)
    8. 6.8 Typical Characteristics (VIN = 24 V)
    9. 6.9 Typical Characteristics (VIN = 36 V)
  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  Input Capacitor Selection
      3. 7.3.3  Output Capacitor Selection
      4. 7.3.4  Transient Response
      5. 7.3.5  Feed-Forward Capacitor
      6. 7.3.6  Switching Frequency (RT)
      7. 7.3.7  Synchronization (SYNC/MODE)
      8. 7.3.8  Output Enable (EN)
      9. 7.3.9  Programmable System UVLO (EN)
      10. 7.3.10 Internal LDO and BIAS_SEL
      11. 7.3.11 Power Good (PGOOD) and Power Good Pull-Up (PGOOD_PU)
      12. 7.3.12 Mode Select (Auto or FPWM)
      13. 7.3.13 Soft Start and Voltage Tracking
      14. 7.3.14 Voltage Dropout
      15. 7.3.15 Overcurrent Protection (OCP)
      16. 7.3.16 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Auto Mode
      3. 7.4.3 FPWM Mode
      4. 7.4.4 Shutdown Mode
  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 Voltage Setpoint
        2. 8.2.2.2 Setting the Switching Frequency
        3. 8.2.2.3 Input Capacitors
        4. 8.2.2.4 Output Capacitor Selection
        5. 8.2.2.5 Feed-Forward Capacitor (CFF)
        6. 8.2.2.6 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Theta JA vs PCB Area
    4. 10.4 Package Specifications
    5. 10.5 EMI
      1. 10.5.1 EMI Plots
  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 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
    1. 12.1 Tape and Reel Information

7.3.6 Switching Frequency (RT)

The recommended switching frequency range of the LMZM33606 is 350 kHz to 1.2 MHz. Table 6 shows the allowable output voltage range for several switching frequency settings for three common input voltages. Under some operating conditions, the device can operate at higher switching frequencies (up to 2.2 MHz), however, this will reduce efficiency and thermal performance. The switching frequency can easily be set by connecting a resistor (RRT) between the RT pin and AGND. Additionally, the RT pin can be left floating, and the LMZM33606 operates at 500 kHz default switching frequency. Use Equation 3 to calculate the RRT value for a desired frequency or simply select from Table 6.

The switching frequency must be selected based on the output voltage setting of the device. See Table 6 for RRT values and the allowable output voltage range at a given switching frequency for several common input voltages. For the most efficient solution, always select the lowest allowable frequency.

Equation 3. LMZM33606 RTeq-01-snvsb11.gif

Table 6. Switching Frequency vs Output Voltage

SWITCHING FREQUENCY (kHz) RRT RESISTOR (kΩ) VIN = 5 V (±10%) VIN = 12 V (±10%) VIN = 24 V (±10%)
VOUT RANGE (V) VOUT RANGE (V) VOUT RANGE (V)
MIN MAX MIN MAX MIN MAX
350 115 1 4 1 8.2 1 8.4
400 100 1 4 1 8.8 1 9.9
500 78.7 or open 1 4 1 9.9 1.1 13.9
600 64.9 1 4 1 9.9 1.3 15.6
700 54.9 1 3.5 1 9.7 1.5 16.9
800 47.5 1 3.4 1 9.6 1.7 18
1000 38.3 1 3.4 1.1 9.3 2.1 20
1200 31.6 1 3.3 1.3 9.1 2.5 19.1
1500 25.5 1 2.9 1.8 8.1 3.2 18.1
1800 21.0 1.1 2.7 2.1 7.7 3.9 17.2
2000 19.1 1.2 2.5 2.5 7.5 4.4 16.5
2200 17.4 1.3 2.4 2.7 7.2 4.8 15.9