ZHCSIE8C June 2018 – October 2020 LMR33630-Q1
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 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 Custom Design With WEBENCH? Tools
- 8.2.2.2 Choosing the Switching Frequency
- 8.2.2.3 Setting the Output Voltage
- 8.2.2.4 Inductor Selection
- 8.2.2.5 Output Capacitor Selection
- 8.2.2.6 Input Capacitor Selection
- 8.2.2.7 CBOOT
- 8.2.2.8 VCC
- 8.2.2.9 CFF Selection
- 8.2.2.10 External UVLO
- 8.2.2.11 Maximum Ambient Temperature
- 8.2.3 Application Curves
- 8.3 What to Do and What Not to Do
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
封裝選項
請參考 PDF 數據表獲取器件具體的封裝圖。
機械數據 (封裝 | 引腳)
- RNX|12
散熱焊盤機械數據 (封裝 | 引腳)
- RNX|12
訂購信息
8.2.2.3 Setting the Output Voltage
The output voltage of the LMR33630-Q1 is externally adjustable using a resistor divider network. The range of recommended output voltage is found in Section 6.3. The divider network is comprised of RFBT and RFBB, and closes the loop between the output voltage and the converter. The converter regulates the output voltage by holding the voltage on the FB pin equal to the internal reference voltage, VREF. The resistance of the divider is a compromise between excessive noise pick-up and excessive loading of the output. Smaller values of resistance reduce noise sensitivity but also reduce the light-load efficiency. The recommended value for RFBT is 100 kΩ; with a maximum value of 1 MΩ. If a 1 MΩ is selected for RFBT, then a feedforward capacitor must be used across this resistor to provide adequate loop phase margin (see Section 8.2.2.9). Once RFBT is selected, Equation 3 is used to select RFBB. VREF is nominally 1 V (see Section 6.5 for limits).
For this 5-V example, RFBT = 100 kΩ and RFBB = 24.9 kΩ are chosen.