ZHCSK76 September 2019 LM74202-Q1
PRODUCTION DATA.
- 1 特性
- 2 应用
- 3 说明
- 4 修订历史记录
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Parameter Measurement Information
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Undervoltage Lockout (UVLO)
- 8.3.2 Overvoltage Protection (OVP)
- 8.3.3 Reverse Battery Protection
- 8.3.4 Hot Plug-In and In-Rush Current Control
- 8.3.5 Overload and Short Circuit Protection
- 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
- 10Power Supply Recommendations
- 11Layout
- 12器件和文档支持
- 13机械、封装和可订购信息
8.3.5.4 Current Monitoring
The current source at IMON terminal is internally configured to be proportional to the current flowing from IN to OUT. This current can be converted into a voltage using a resistor R(IMON) from IMON terminal to RTN terminal. The IMON voltage can be used as a means of monitoring current flow through the system. The maximum voltage range (V(IMONmax) for monitoring the current is limited to minimum of ([V(IN) – 1.5 V, 4 V]) to ensure linear output. This puts a limitation on maximum value of R(IMON) resistor and is determined by Equation 6.
The output voltage at IMON terminal is calculated using Equation 7 and Equation 8.
For IOUT > 50 mA,
where
- GAIN(IMON) is the gain factor I(IMON):I(OUT)
- I(OUT) is the load current
- I(MON_OS) = 2 µA (Typical)
For IOUT < 50 mA (typical), IMON output current is close to I(MON_OS) and Equation 8 provides the voltage output with RIMON.
This pin must not have a bypass capacitor to avoid delay in the current monitoring information.
In case of reverse input polarity fault, an external 100-kΩ resistor is recommended between IMON pin and ADC input to limit the current through the ESD protection structures of the ADC.