ZHCSEC5D November 2015 – May 2021 TPS65235
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 Boost Converter
- 7.3.2 Linear Regulator and Current Limit
- 7.3.3 Boost Converter Current Limit
- 7.3.4 Charge Pump
- 7.3.5 Slew Rate Control
- 7.3.6 Short Circuit Protection, Hiccup and Overtemperature Protection
- 7.3.7 Tone Generation
- 7.3.8 Tone Detection
- 7.3.9 Disable and Enable
- 7.3.10 Component Selection
- 7.4 Device Functional Modes
- 7.5 Programming
- 7.6 Register Maps
- 8 Application and Implementation
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
7.3.3 Boost Converter Current Limit
The boost converter has the cycle-by-cycle peak current limit on the internal Power MOSFET switch to serve as the secondary protection when LNB output is hard short. With ISW bit default setting “0” on I2C control register 0x01, the switch current limit ISW is proportional as LDO current limit I(OCP) set by ISET pin resistor, and the relationship can be expressed as:
For the 5 V VIN, if LNB current load is up to 1 A, the ISW bit should be written as “1”, the switch current limit ISW for the internal Power MOSFET is:
While due to the high power loss at 5 V, VIN, it has a chance to trigger the thermal shutdown before the loading is up to 1 A, especially the VLNB output is high.