ZHCSF41B December 2015 – March 2021 LMR16030
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 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
- 7.3.1 Fixed Frequency Peak Current Mode Control
- 7.3.2 Slope Compensation
- 7.3.3 Sleep Mode
- 7.3.4 Low Dropout Operation and Bootstrap Voltage (BOOT)
- 7.3.5 Adjustable Output Voltage
- 7.3.6 Enable and Adjustable Undervoltage Lockout
- 7.3.7 External Soft Start
- 7.3.8 Switching Frequency and Synchronization (RT/SYNC)
- 7.3.9 Power Good (PGOOD)
- 7.3.10 Overcurrent and Short Circuit Protection
- 7.3.11 Overvoltage Protection
- 7.3.12 Thermal Shutdown
- 7.4 Device Functional Modes
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
7.3.7 External Soft Start
The LMR16030S has an external soft-start pin for programmable output ramp-up time. The soft-start feature is used to prevent inrush current impacting the LMR16030 and its load when power is first applied. The soft-start time can be programed by connecting an external capacitor CSS from SS pin to GND. An internal current source (typically ISS = 3 μA) charges CSS and generates a ramp from 0 V to VREF. The soft-start time can be calculated by Equation 4:
Equation 4. 
The internal soft start resets while the device is disabled or in thermal shutdown.