ZHCSGJ1 August 2017 UCC27712-Q1
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
-
8 Application 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 Selecting HI and LI Low Pass Filter Components (RHI, RLI, CHI, CLI)
- 8.2.2.2 Selecting Bootstrap Capacitor (CBOOT)
- 8.2.2.3 Selecting VDD Bypass/Holdup Capacitor (CVDD) and Rbias
- 8.2.2.4 Selecting Bootstrap Resistor (RBOOT)
- 8.2.2.5 Selecting Gate Resistor RON/ROFF
- 8.2.2.6 Selecting Bootstrap Diode
- 8.2.2.7 Estimate the UCC27712-Q1 Power Losses (PUCC27712-Q1)
- 8.2.2.8 Estimating Junction Temperature
- 8.2.2.9 Operation With IGBT's
- 8.2.3 Application Curves
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機械、封裝和可訂購信息
8.2.2.4 Selecting Bootstrap Resistor (RBOOT)
Resistor RBOOT is selected to limit the current in DBOOT and limit the ramp up slew rate of voltage of HB-HS to avoid the phenomenon shown in Figure 45. It is recommended when using the UCC27712-Q1 that RBOOT is between 2 Ω and 20 Ω. For this design we selected an RBOOT current limiting resistor of 2.2 Ω. The bootstrap diode current (IDBOOT(pk)) was limited to roughly 5.0 A.
The power dissipation capability of the bootstrap resistor is important. The bootstrap resistor must be able to withstand the short period of high power dissipation during the initial charging sequence of the boot-strap capacitor. This energy is equivalent to 1/2 × CBOOT × V2. This energy is dissipated during the charging time of the bootstrap capacitor (~3 × RBOOT × CBOOT). Special attention must be paid to use a bigger size RBOOT when a bigger value of CBOOT is chosen.