ZHCSLW5A October 2019 – November 2020 LMR50410-Q1
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 Device Comparison Table
- 6 Pin Configuration and Functions
- 7 Specifications
- 8 Detailed Description
-
9 Application and Implementation
- 9.1 Application Information
- 9.2
Typical Application
- 9.2.1 Design Requirements
- 9.2.2
Detailed Design Procedure
- 9.2.2.1 Custom Design With WEBENCH® Tools
- 9.2.2.2 Output Voltage Set-Point
- 9.2.2.3 Switching Frequency
- 9.2.2.4 Inductor Selection
- 9.2.2.5 Output Capacitor Selection
- 9.2.2.6 Input Capacitor Selection
- 9.2.2.7 Bootstrap Capacitor
- 9.2.2.8 Undervoltage Lockout Set-Point
- 9.2.2.9 Maximum Ambient Temperature
- 9.2.3 Application Curves
- 10Power Supply Recommendations
- 11Layout
- 12Device and Documentation Support
- 13Mechanical, Packaging, and Orderable Information
8.3.3 Enable
The voltage on the EN pin controls the ON/OFF operation of the LMR50410-Q1. A voltage of less than 0.95 V shuts down the device, while a voltage of greater than 1.36 V is required to start the converter. The EN pin is an input and cannot be left open or floating. The simplest way to enable the operation of the LMR50410-Q1 is to connect the EN to VIN. This allows self-start-up of the LMR50410-Q1 when VIN is within the operating range.
Many applications benefit from the employment of an enable divider RENT and RENB (Figure 8-3) to establish a precision system UVLO level for the converter. System UVLO can be used for supplies operating from utility power as well as battery power. It can be used for sequencing, ensuring reliable operation, or supplying protection, such as a battery discharge level. An external logic signal can also be used to drive EN input for system sequencing and protection. Note, the EN pin voltage must not to be greater than VIN + 0.3 V. It is not recommended to apply EN voltage when VIN is 0 V.
Figure 8-3 System UVLO by Enable Divider