ZHCS901E May 2012 – September 2021 TPS55340
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 Applications
- 8.2.1
Boost Converter
- 8.2.1.1 Design Requirements
- 8.2.1.2
Detailed Design Procedure
- 8.2.1.2.1 Custom Design with WEBENCH Tools
- 8.2.1.2.2 Selecting the Switching Frequency (R4)
- 8.2.1.2.3 Determining the Duty Cycle
- 8.2.1.2.4 Selecting the Inductor (L1)
- 8.2.1.2.5 Computing the Maximum Output Current
- 8.2.1.2.6 Selecting the Output Capacitors (C8, C9, C10)
- 8.2.1.2.7 Selecting the Input Capacitors (C2, C7)
- 8.2.1.2.8 Setting Output Voltage (R1, R2)
- 8.2.1.2.9 Setting the Soft-start Time (C7)
- 8.2.1.2.10 Selecting the Schottky Diode (D1)
- 8.2.1.2.11 Compensating the Control Loop (R3, C4, C5)
- 8.2.1.3 Application Curves
- 8.2.2
SEPIC Converter
- 8.2.2.1 Design Requirements
- 8.2.2.2
Detailed Design Procedure
- 8.2.2.2.1 Selecting the Switching Frequency (R4)
- 8.2.2.2.2 Duty Cycle
- 8.2.2.2.3 Selecting the Inductor (L1)
- 8.2.2.2.4 Calculating the Maximum Output Current
- 8.2.2.2.5 Selecting the Output Capacitors (C8, C9, C10)
- 8.2.2.2.6 Selecting the Series Capacitor (C6)
- 8.2.2.2.7 Selecting the Input Capacitor (C2, C7)
- 8.2.2.2.8 Selecting the Schottky Diode (D1)
- 8.2.2.2.9 Setting the Output Voltage (R1, R2)
- 8.2.2.2.10 Setting the Soft-start Time (C3)
- 8.2.2.2.11 MOSFET Rating Considerations
- 8.2.2.2.12 Compensating the Control Loop (R3, C4)
- 8.2.2.3 Application Curves
- 8.2.1
Boost Converter
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
封裝選項
機械數(shù)據(jù) (封裝 | 引腳)
散熱焊盤機械數(shù)據(jù) (封裝 | 引腳)
訂購信息
8.2.2.2.3 Selecting the Inductor (L1)
With an estimated 85% efficiency, the input current is calculated with Equation 9 to be 2.35 A. With KIND of 0.3 and the maximum 18-V input voltage, the minimum inductance is calculated to be 10.5 μH using Equation 41. The nearest standard value of 12 μH is used. As mentioned previously, this equation assumes a coupled inductor is used.
The inductor ripple current is recalculated to be 615 mA with Equation 42. The peak current is calculated to be
3.69 A. The typical current limit is used as the saturation rating for the inductor used. The RMS current for La is approximately the average input current of 2.35 A. The RMS current for Lb is approximately the output current of 1 A. For this design, a CoilCraft MSD1260-123 is used with 6.86-A saturation, 74-mΩ DCR, and 3.12-A RMS current rating for one winding.
