ZHCSJK1G November 2002 – May 2019 LM2733
PRODUCTION DATA.
- 1 特性
- 2 應(yīng)用
- 3 說(shuō)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 the External Capacitors
- 8.2.2.2 Selecting the Output Capacitor
- 8.2.2.3 Selecting the Input Capacitor
- 8.2.2.4 Feedforward Compensation
- 8.2.2.5 Selecting Diodes
- 8.2.2.6 Setting the Output Voltage
- 8.2.2.7 Switching Frequency
- 8.2.2.8 Duty Cycle
- 8.2.2.9 Inductance Value
- 8.2.2.10 Maximum Switch Current
- 8.2.2.11 Calculating Load Current
- 8.2.2.12 Design Parameters VSW and ISW
- 8.2.2.13 Thermal Considerations
- 8.2.2.14 Minimum Inductance
- 8.2.2.15 Inductor Suppliers
- 8.2.3 Application Curves
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機(jī)械、封裝和可訂購(gòu)信息
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
- DBV|5
散熱焊盤(pán)機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購(gòu)信息
8.2.2.8 Duty Cycle
The maximum duty cycle of the switching regulator determines the maximum boost ratio of output-to-input voltage that the converter can attain in continuous mode of operation. The duty cycle for a given boost application is defined as:
This applies for continuous mode operation.
The equation shown for calculating duty cycle incorporates terms for the FET switch voltage and diode forward voltage. The actual duty cycle measured in operation will also be affected slightly by other power losses in the circuit such as wire losses in the inductor, switching losses, and capacitor ripple current losses from self-heating. Therefore, the actual (effective) duty cycle measured may be slightly higher than calculated to compensate for these power losses. A good approximation for effective duty cycle is :
Where the efficiency can be approximated from the curves provided.