ZHCSHY7A April 2018 – May 2018 UCC28742
PRODUCTION DATA.
- 1 特性
- 2 應(yīng)用
- 3 說明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3 Feature Description
- 7.4 Device Functional Modes
-
8 Applications and Implementation
- 8.1 Application Information
- 8.2
Typical Application
- 8.2.1 Design Requirements
- 8.2.2
Detailed Design Procedure
- 8.2.2.1 Custom Design With WEBENCH® Tools
- 8.2.2.2 VDD Capacitance, CDD
- 8.2.2.3 VDD Start-Up Resistance, RSTR
- 8.2.2.4 Input Bulk Capacitance and Minimum Bulk Voltage
- 8.2.2.5 Transformer Turns Ratio, Inductance, Primary-Peak Current
- 8.2.2.6 Transformer Parameter Verification
- 8.2.2.7 VS Resistor Divider and Line Compensation
- 8.2.2.8 Standby Power Estimate
- 8.2.2.9 Output Capacitance
- 8.2.2.10 Feedback Loop Design Consideration
- 8.2.3 Application Curves
- 8.3 Do's and Don'ts
- 9 Power Supply Recommendations
- 10Layout
-
11器件和文檔支持
- 11.1
器件支持
- 11.1.1 開發(fā)支持
- 11.1.2
器件命名規(guī)則
- 11.1.2.1 電容術(shù)語（以法拉為單位）
- 11.1.2.2 占空比術(shù)語
- 11.1.2.3 頻率術(shù)語（以赫茲為單位）
- 11.1.2.4 電流術(shù)語（以安培為單位）
- 11.1.2.5 電流和電壓調(diào)節(jié)術(shù)語
- 11.1.2.6 變壓器術(shù)語
- 11.1.2.7 功率術(shù)語（以瓦特為單位）
- 11.1.2.8 電阻術(shù)語（以 Ω 為單位）
- 11.1.2.9 時序術(shù)語（以秒為單位）
- 11.1.2.10 電壓術(shù)語（以伏特為單位）
- 11.1.2.11 交流電壓術(shù)語（以 VRMS 為單位）
- 11.1.2.12 效率術(shù)語
- 11.2 文檔支持
- 11.3 接收文檔更新通知
- 11.4 社區(qū)資源
- 11.5 商標
- 11.6 靜電放電警告
- 11.7 術(shù)語表
- 11.1
器件支持
- 12機械、封裝和可訂購信息
8.2.2.2 VDD Capacitance, CDD
The capacitance on VDD needs to supply the device operating current until the output of the converter reaches the target minimum operating voltage. At this time the auxiliary winding can sustain the voltage to the UCC28742. The total output current available to the load and to charge the output capacitors is the constant-current regulation target. The equation below assumes the output current of the flyback is available to charge the output capacitance until the minimum output voltage is achieved to maintain VDD above its VVDD(on). The gate-drive current depends on particular MOSFET to be used. If with an estimated average 1.0 mA of gate-drive current, CDD is determined by Equation 6, and at IOCC, VOCC = VOCV.
