ZHCSCK0C June 2014 – September 2021 TPS55340-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
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3 Feature Description
- 7.4 Device Functional Modes
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Applications
- 8.2.1
TPS55340-Q1 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 Capacitor (C8 through C10)
- 8.2.1.2.7 Selecting the Input Capacitors (C2 and C7)
- 8.2.1.2.8 Setting the Output Voltage (R1 and 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, and C5)
- 8.2.1.3 Application Curves
- 8.2.2
TPS55340-Q1 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 Capacitor (C8 Through C10)
- 8.2.2.2.6 Selecting the Series Capacitor (C6)
- 8.2.2.2.7 Selecting the Input Capacitor (C2 and C7)
- 8.2.2.2.8 Selecting the Schottky Diode (D1)
- 8.2.2.2.9 Setting the Output Voltage (R1 and 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 and C4)
- 8.2.2.3 Application Curves
- 8.2.1
TPS55340-Q1 Boost Converter
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
8.2.2.2.3 Selecting the Inductor (L1)
With an estimated 85% efficiency, the input current is calculated to be 2.35 A using Equation 11. The minimum inductance is calculated to be 10.5 μH using Equation 43 with a K(IND) value of 0.3 and a maximum input value of 18 V. The nearest standard value of 12 μH is used. This equation assumes that a coupled inductor is used.
The inductor ripple current is recalculated to be 615 mA using Equation 44. The peak current is calculated to be 3.69 A. For the saturation rating of the selected inductor, use the typical current limit. The RMS current for La is approximately the average input current 2.35 A. The RMS current for Lb is approximately the output current of 1 A. For this design, a CoilCraft MSD1260-123 was used with 6.86-A saturation, 74-mΩ DCR, and 3.12-A RMS current rating for one winding.
