ZHCSMU1G October 2020 – May 2024 LMR43610-Q1 , LMR43620-Q1
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 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 Enable, Start-Up, and Shutdown
- 7.3.2 External CLK SYNC (with MODE/SYNC)
- 7.3.3 Adjustable Switching Frequency (with RT)
- 7.3.4 Power-Good Output Operation
- 7.3.5 Internal LDO, VCC, and VOUT/FB Input
- 7.3.6 Bootstrap Voltage and VBOOT-UVLO (BOOT Terminal)
- 7.3.7 Output Voltage Selection
- 7.3.8 Spread Spectrum
- 7.3.9 Soft Start and Recovery from Dropout
- 7.3.10 Current Limit and Short Circuit
- 7.3.11 Thermal Shutdown
- 7.3.12 Input Supply Current
- 7.4 Device Functional Modes
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Application
- 8.2.1 Design Requirements
- 8.2.2 Detailed Design Procedure
- 8.2.3 Application Curves
- 8.3 Best Design Practices
- 8.4 Power Supply Recommendations
- 8.5 Layout
- 9 Device and Documentation Support
- 10Revision History
- 11Mechanical, Packaging, and Orderable Information
7.3.2.1 Pulse-Dependent MODE/SYNC Pin Control
Most systems that require more than a single mode of operation from the LMR436x0-Q1 are controlled by digital circuitry such as a microprocessor. These systems can generate dynamic signals easily but have difficulty generating multi-level signals. Pulse-dependent MODE/SYNC pin control is useful with these systems. To initiate pulse-dependent MODE/SYNC pin control, a valid sync signal must be applied. Table 7-1 shows a summary of the pulse dependent mode selection settings.
| MODE/SYNC INPUT | MODE |
|---|---|
| > VMODE_H | FPWM with spread spectrum factory setting |
| < VMODE_L | Auto mode with spread spectrum factory setting |
| Synchronization Clock | SYNC mode |
Figure 7-4 shows the transition between auto mode and FPWM mode while in pulse-dependent MODE/SYNC control. The LMR436x0-Q1 transitions to a new mode of operation after the time, tMODE. Figure 7-4 and Figure 7-5 show the details.
Figure 7-4 Transition from Auto Mode and
FPWM ModeIf MODE/SYNC voltage remains constant longer than tMODE, the LMR436x0-Q1 enters either auto mode or FPWM mode with spread spectrum turned on (if factory setting is enabled) and MODE/SYNC continues to operate in pulse-dependent scheme.
Figure 7-5 Transition from SYNC Mode to
Auto Mode
Figure 7-6 Transition from SYNC Mode to
FPWM Mode