ZHCSNF0B May 2018 – October 2021 ISOW1412 , ISOW1432
PRODMIX
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 说明（续）
- 6 Device Comparison Table
- 7 Pin Configuration and Functions
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8 Specifications
- 8.1 Absolute Maximum Ratings
- 8.2 Recommended Operating Conditions
- 8.3 Thermal Information
- 8.4 Power Ratings
- 8.5 Insulation Specifications
- 8.6 Safety-Related Certifications
- 8.7 Safety Limiting Values
- 8.8 Electrical Characteristics
- 8.9 Supply Current Characteristics at VISOOUT = 3.3 V
- 8.10 Supply Current Characteristics at VISOOUT = 5 V
- 8.11 Switching Characteristics at VISOOUT = 3.3 V
- 8.12 Switching Characteristics at VISOOUT = 5 V
- 8.13 Insulation Characteristics Curves
- 8.14 Typical Characteristics
- 9 Parameter Measurement Information
- 10Detailed Description
- 11Application and Implementation
- 12Power Supply Recommendations
- 13Layout
- 14Device and Documentation Support
- 15Mechanical, Packaging, and Orderable Information
10.6.2 Protection Features
The ISOW14x2 family of devices has multiple protection features to create a robust system level solution.
- The first feature is an Enable/Fault protection feature. This EN/FLT pin can be used as either an input pin to enable or disable the integrated DC-DC power converter or as an output pin which works as an alert signal if the power converter is not operating properly. In the /Fault use case, a fault is reported if VDD > 7 V, VDD < 2.5 V, or if the junction temperature >170°C. When a fault is detected, this pin will go low, disabling the DC-DC converter to prevent any damage.
Figure 10-3 EN Fault Pin Diagram
- An over-voltage clamp feature is present on VISOOUT which will clamp the voltage at 6 V at Profibus mode (MODE = VISOOUT ) or 4V at RS485 mode (MODE = GND2), if there is an increase in voltage seen. For device reliability, it is recommended that VISOOUT stays lower than the over-clamp voltage for device reliability.
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Over-Voltage Lock Out (OVLO) on VDD will occur when a voltage higher than 7 V on VDD is seen. At OVLO, the device will go into a low power state and the EN/FLT pin will go low.
- These devices are protected against output overload and short circuit. In cases of overload or short on power converter output VISOOUT, maximum duty cycle of power converter is limited. In cases of driver bus short circuit due to the external power supply cable shorting to the bus cable, or due to bus contention, short circuit current protection on RS-485 chip restricts the bus current to ±250 mA maximum.
- Thermal protection is also integrated to help prevent the device from getting damaged under such scenarios. An increase in the die temperature is monitored and the device is disabled when the die temperature becomes 165℃ (typical), thus disabling the short condition. The device is re-enabled when the junction temperature becomes 155℃ (typical). If an overload or output short-circuit condition prevails, this protection cycle is repeated. Care should be taken in the system design to prevent repeated or prolonged exposure to bus shorts as this exposes the device to high junction temperatures for extreme amounts of time affecting device reliability.