JAJSE40A October   2017  – February 2018 UCC28780

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      概略回路図
      2.      45W、20VのGaN-ACFアダプタの効率
  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 of SOIC
    5. 6.5 Thermal Information of WQFN
    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 Detailed Pin Description
      1. 7.3.1 BUR Pin (Programmable Burst Mode)
      2. 7.3.2 FB Pin (Feedback Pin)
      3. 7.3.3 VDD Pin (Device Bias Supply)
      4. 7.3.4 REF Pin (Internal 5-V Bias)
      5. 7.3.5 HVG and SWS Pins
      6. 7.3.6 RTZ Pin (Sets Delay for Transition Time to Zero)
      7. 7.3.7 RDM Pin (Sets Synthesized Demagnetization Time for ZVS Tuning)
      8. 7.3.8 RUN Pin (Driver Enable Pin)
      9. 7.3.9 SET Pin
    4. 7.4 Device Functional Modes
      1. 7.4.1  Adaptive ZVS Control with Auto-Tuning
      2. 7.4.2  Dead-Time Optimization
      3. 7.4.3  Control Law across Entire Load Range
      4. 7.4.4  Adaptive Amplitude Modulation (AAM)
      5. 7.4.5  Adaptive Burst Mode (ABM)
      6. 7.4.6  Low Power Mode (LPM)
      7. 7.4.7  Standby Power Mode (SBP)
      8. 7.4.8  Startup Sequence
      9. 7.4.9  Survival Mode of VDD
      10. 7.4.10 System Fault Protections
        1. 7.4.10.1 Brown-In and Brown-Out
        2. 7.4.10.2 Output Over-Voltage Protection
        3. 7.4.10.3 Over-Temperature Protection
        4. 7.4.10.4 Programmable Over-Power Protection
        5. 7.4.10.5 Peak Current Limit
        6. 7.4.10.6 Output Short-Circuit Protection
        7. 7.4.10.7 Over-Current Protection
        8. 7.4.10.8 Thermal Shutdown
      11. 7.4.11 Pin Open/Short Protections
        1. 7.4.11.1 Protections on CS pin Fault
        2. 7.4.11.2 Protections on HVG pin Fault
        3. 7.4.11.3 Protections on RDM and RTZ pin Faults
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application Circuit
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Input Bulk Capacitance and Minimum Bulk Voltage
        2. 8.2.2.2 Transformer Calculations
          1. 8.2.2.2.1 Primary-to-Secondary Turns Ratio (NPS)
          2. 8.2.2.2.2 Primary Magnetizing Inductance (LM)
          3. 8.2.2.2.3 Primary Turns (NP)
          4. 8.2.2.2.4 Secondary Turns (NS)
          5. 8.2.2.2.5 Turns of Auxiliary Winding (NA)
          6. 8.2.2.2.6 Winding and Magnetic Core Materials
        3. 8.2.2.3 Clamp Capacitor Calculation
        4. 8.2.2.4 Bleed-Resistor Calculation
        5. 8.2.2.5 Output Filter Calculation
        6. 8.2.2.6 Calculation of ZVS Sensing Network
        7. 8.2.2.7 Calculation of Compensation Network
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 General Considerations
      2. 10.1.2 RDM and RTZ Pins
      3. 10.1.3 SWS Pin
      4. 10.1.4 VS Pin
      5. 10.1.5 BUR Pin
      6. 10.1.6 FB Pin
      7. 10.1.7 CS Pin
      8. 10.1.8 GND Pin
    2. 10.2 Layout Example
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 ドキュメントのサポート
      1. 11.1.1 関連資料
    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

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • D|16
  • RTE|16
サーマルパッド・メカニカル・データ
発注情報

7.4.3 Control Law across Entire Load Range

UCC28780 contains four modes of operation summarized in Table 1. Starting from heavier load, the AAM mode forces PWML and PWMH into complementary switching with ZVS tuning enabled. ABM mode generates a group of PWML and PWMH pulses as a burst packet, and adjusts the burst off-time to regulate the output voltage. At the same time, the burst frequency variation is confined above 20kHz by adjusting the number of PWML and PWMH pulses per packet to mitigate audible noise and reduce burst output ripple. In LPM and SBP modes, PWMH and the ZVS tuning loop are disabled, so the converter operates in valley-switching.

Table 1. Functional Modes

MODE OPERATION PWMH ZVS
AAM Adaptive Amplitude Modulation ACF operation with PWML and PWMH in complementary switching Enabled Yes
ABM Adaptive Burst Mode Variable fBUR > 20 kHz, ACF operation in complementary switching Enabled Yes
LPM Low Power Mode Fix fBUR ≈ 25 kHz, valley-switching Disabled No
SBP StandBy Power Variable fBUR < 25 kHz, valley-switching Disabled No

Figure 23 addresses the critical parameter changes among the four operating modes, where VCST is the peak current threshold compared with the current-sense voltage from CS pin, fSW is the switching frequency of PWML, fBUR is the burst frequency, and NSW is the pulse number of PWML per burst packet. The following section explains the detailed operation of each mode.

UCC28780 Control-Law.gifFigure 23. Control Law Over Entire Load Range