ZHCSLU1B October 2022 – August 2024 LM64440-Q1 , LM64460-Q1
PRODUCTION DATA
- 1
- 1 特性
- 2 应用
- 3 说明
- 4 Device Comparison Table
- 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 Input Voltage Range (VIN1, VIN2)
- 7.3.2 Output Voltage Setpoint (FB)
- 7.3.3 Precision Enable and Input Voltage UVLO (EN)
- 7.3.4 MODE/SYNC Operation
- 7.3.5 Clock Locking
- 7.3.6 Power-Good Monitor (PGOOD)
- 7.3.7 Bias Supply Regulator (VCC, BIAS)
- 7.3.8 Bootstrap Voltage and UVLO (CBOOT)
- 7.3.9 Spread Spectrum
- 7.3.10 Soft Start and Recovery From Dropout
- 7.3.11 Overcurrent and Short-Circuit Protection
- 7.3.12 Thermal Shutdown
- 7.3.13 Input Supply Current
- 7.4 Device Functional Modes
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Applications
- 8.2.1 Design 1 – Automotive Synchronous 6A Buck Regulator at 2.1MHz
- 8.2.2
Design 2 – Automotive Synchronous 4A Buck Regulator at 2.1MHz
- 8.2.2.1 Design Requirements
- 8.2.2.2
Detailed Design Procedure
- 8.2.2.2.1 Custom Design With WEBENCH® Tools
- 8.2.2.2.2 Setting the Output Voltage
- 8.2.2.2.3 Choosing the Switching Frequency
- 8.2.2.2.4 Inductor Selection
- 8.2.2.2.5 Output Capacitor Selection
- 8.2.2.2.6 Input Capacitor Selection
- 8.2.2.2.7 Bootstrap Capacitor
- 8.2.2.2.8 VCC Capacitor
- 8.2.2.2.9 BIAS Power Connection
- 8.2.2.2.10 Feedforward Network
- 8.2.2.2.11 Input Voltage UVLO
- 8.2.2.3 Application Curves
- 8.3 Power Supply Recommendations
- 8.4 Layout
- 9 Device and Documentation Support
- 10Revision History
- 11Mechanical, Packaging, and Orderable Information
7.3.1 Input Voltage Range (VIN1, VIN2)
With a steady-state input voltage range from 3V to 36V, the LM644x0-Q1 is intended for step-down conversions from typical 12V and 24V automotive supply rails. The schematic circuit in Figure 7-1 shows all the necessary components to implement an LM644x0-Q1 step-down regulator using a single input supply.
Figure 7-1 LM64460-Q1
Schematic Diagram with Input Voltage Operating Range of 3V
to 36VThe minimum input voltage required for start-up is 3.95V. Take extra care to make sure that the voltage at the VIN pins of the converter (VIN1 and VIN2) does not exceed the absolute maximum voltage rating of 42V during line or load transient events. Voltage ringing at the VIN pins that exceeds the Absolute Maximum Ratings can damage the IC.