ZHCSO70A march 2023 – may 2023 LMR36501 , LMR36502
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Device Comparison Table
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Enable, Shutdown, and Start-up
- 8.3.2 Adjustable Switching Frequency (with RT)
- 8.3.3 Power-Good Output Operation
- 8.3.4 Internal LDO, VCC UVLO, and VOUT/FB Input
- 8.3.5 Bootstrap Voltage and VBOOT-UVLO (BOOT Terminal)
- 8.3.6 Output Voltage Selection
- 8.3.7 Soft Start and Recovery from Dropout
- 8.3.8 Current Limit and Short Circuit
- 8.3.9 Thermal Shutdown
- 8.3.10 Input Supply Current
- 8.4 Device Functional Modes
-
9 Application and Implementation
- 9.1 Application Information
- 9.2
Typical Application
- 9.2.1 Design Requirements
- 9.2.2 Detailed Design Procedure
- 9.2.3 Application Curves
- 9.3 Best Design Practices
- 9.4 Power Supply Recommendations
- 9.5 Layout
- 10Device and Documentation Support
- 11Mechanical, Packaging, and Orderable Information
封裝選項
機械數(shù)據(jù) (封裝 | 引腳)
- RPE|9
散熱焊盤機械數(shù)據(jù) (封裝 | 引腳)
- RPE|9
訂購信息
8.3.2 Adjustable Switching Frequency (with RT)
The select variants in the LMR3650x family with the RT pin allow the power designers to set any desired operating frequency between 200 kHz and 2.2 MHz in their applications. See Figure 8-3 to determine the resistor value needed for the desired switching frequency. See Table 8-1 for selection on programming the RT pin.
Table 8-1 RT Pin Setting
| RT INPUT | SWITCHING FREQUENCY |
|---|---|
| VCC | 1 MHz |
| GND | 2.2 MHz |
| RT to GND | Adjustable according to Figure 8-3 |
| Float (Not Recommended) | No Switching |
Equation 1 can be used to calculate the value of RT for a desired frequency.
Equation 1. 
where
- RT is the frequency setting resistor value (kΩ).
- FSW is the switching frequency (kHz).
Figure 8-3 RT Values vs
Frequency