ZHCSCY3E October 2014 – October 2018 LM5160 , LM5160A
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 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 Isolated Fly-Buck (18-V to 32-V Input, 12-V, 4.5-W Isolated Output)
- 8.2.3 LM5160A Isolated Fly-Buck (18-V to 32-V Input, 12-V, 4.5-W Isolated Output)
- 8.2.1
LM5160 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
7.3.7 Current Limit
The LM5160 provides an intelligent current limit off-timer that adjusts the off-time to reduce the foldback in the current limit. If the peak value of the current in the buck switch exceeds 2.5 A (typical), the present on-time interval is immediately terminated and a non-resettable off-timer is initiated. The length of the off-time is controlled by the FB voltage and the input voltage VIN. As an example, when VFB = 0 V and VIN = 24 V, the off-time is set to 10 µs. This condition occurs if the output is shorted or during the initial phase of start-up. In cases of output overload where the FB voltage is greater than zero volts (a soft short), the current limit off-time is reduced. Decreasing the off-time during less severe overloads reduces the current limit foldback, overload recovery time, and start-up time. Calculate the current limit off-time using Equation 5.
