ZHCSDV5C July 2015 – October 2018 LM5160-Q1
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 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
LM5160-Q1 Synchronous Buck (10-V to 60-V Input, 5-V Output, 1.5-A Load)
- 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 Feedback Resistor Divider - RFB1, RFB2
- 8.2.1.2.3 Switching Frequency - RON
- 8.2.1.2.4 Inductor - L
- 8.2.1.2.5 Output Capacitor - COUT
- 8.2.1.2.6 Series Ripple Resistor - RESR
- 8.2.1.2.7 VCC and Bootstrap Capacitors - CVCC, CBST
- 8.2.1.2.8 Input Capacitor - CIN
- 8.2.1.2.9 Soft-Start Capacitor - CSS
- 8.2.1.2.10 EN/UVLO Resistors - RUV1, RUV2
- 8.2.1.3 Application Curves
- 8.2.2 LM5160-Q1 Isolated Fly-Buck (18-V to 32-V Input, 12-V, 4.5-W Isolated Output)
- 8.2.1
LM5160-Q1 Synchronous Buck (10-V to 60-V Input, 5-V Output, 1.5-A Load)
- 8.3 Do's and Don'ts
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文档支持
- 12机械、封装和可订购信息
8.2.2.2.4 Output Capacitor - COUT2
The Fly-Buck output capacitor conducts higher ripple current than a buck converter output capacitor. Calculate the capacitive ripple for the isolated output capacitor based on the time the rectifier diode is off. During this time the entire output current is supplied by the output capacitor. Calculate the required capacitance for a worst-case VOUT2 (VOUT(ISO)) ripple voltage using Equation 24.
where
- ΔVOUT2 is the target ripple at the secondary output.
Equation 24 is an approximation and ignores the ripple components associated with ESR and ESL of the output capacitor. For a ΔVOUT2 = 100 mV, Equation 24 requires COUT2 = 6.5 µF. When selecting a ceramic capacitor, consider its voltage coefficient to ensure sufficient capacitance at the output voltage operating point.