STWD100NYWY3F Watchdog Timer Specifications, Pinout, Characteristics and Application
15 April 2024
Ⅱ. Specifications of STWD100NYWY3F
Ⅲ. DC and AC parameters of STWD100NYWY3F
Ⅳ. The symbol, footprint and pin configuration of STWD100NYWY3F
Ⅴ. Characteristics of STWD100NYWY3F
Ⅵ. How does STWD100NYWY3F work?
Ⅶ. Application examples of STWD100NYWY3F
Ⅷ. How does the STWD100NYWY3F watchdog timer prevent system failures?
STWD100NYWY3F is a watchdog timer produced by STMicroelectronics. This monitoring timer integrated circuit is an independent device and is mainly used to prevent system failures. Certain types of hardware or software errors can cause electronic system failures. The watchdog timer has an input function that clears the watchdog timer periodically within a specified period. When the system is running normally, the monitoring output is not used. If the watchdog timer is not cleared in time, the watchdog output will trigger a processor interrupt or reset.
Alternatives and equivalents:
• STWD100PWWY3F
• Its power consumption is 320 mW.
• Its supply current is 0.026 mA
• It has a reset delay time of 210 ms.
• Its manufacturer is STMicroelectronics.
• The mounting method of STWD100NYWY3F is SMD or SMT.
• STWD100NYWY3F has a length of 2.9 mm, a width of 1.6 mm, and a height of 1.05 mm.
• STWD100NYWY3F belongs to the category of supervisory circuits.
• STWD100NYWY3F has 5 pins and comes in SOT-23-5 package and tape & reel (TR) packaging.
• The minimum operating temperature of this part is -40°C and the maximum operating temperature is 125°C.
• The device's typical operating supply voltage is 5V, its minimum operating supply voltage is 2.7V, and its maximum operating supply voltage is 5.5V.
The table provided outlines the operational measurement settings and both DC and AC properties of the device. These metrics are extracted from tests conducted within the parameters detailed in the accompanying table labeled "Operating and AC Measurement Conditions." Designers should check that the operating conditions in their circuits match those at the time the parameters are quoted.
• Chip enable input
• Automotive qualified
• Current consumption 13 µA typ
• ESD performance
-HBM: 2000 V
-CDM: 1000 V
• Open drain or push-pull WDO’ output
• Packages: SOT23-5 and SC70-5 (SOT323-5)
• Operating temperature range: –40°C to 125°C
• Available watchdog timeout periods are 3.4 ms, 6.3 ms, 102 ms, and 1.6 s
The working principle of the STWD100NYWY3F watchdog timer is relatively simple and efficient. It has an input (WDI) and an output (WDO). The main function of WDI (Watchdog Input) is to clear the internal watchdog timer by periodically triggering within the preset timeout time (twd). When the system is in normal operation, the WDI input is periodically switched or activated to reset the watchdog timer to ensure that it does not trigger an alarm due to timeout. This process is similar to feeding a watchdog so that it remains quiet and continues to perform its monitoring duties. However, if the system fails, such as the system stops working or falls into an endless loop due to hardware or software errors, WDI will not be triggered normally, and the watchdog timer will not be reset in time. Once the preset timeout time twd is exceeded, the watchdog timer will generate a system alarm and output this alarm signal through WDO (Watchdog Output). It's like a watchdog that starts barking because it hasn't been fed for a long time, sounding the alarm that something is wrong with the system. In addition, the STWD100NYWY3F watchdog timer circuit is also equipped with an enable pin EN to control the enabling or disabling of the watchdog function. When the EN pin is floating, the device is enabled by default. By controlling the status of the EN pin, users can flexibly turn on or off the watchdog function according to actual needs.
In general, the STWD100NYWY3F watchdog timer monitors the operating status of the system in real time and will quickly output an alarm signal once a system fault is detected. This mechanism effectively prevents the system from being unable to recover due to failures, thus ensuring the stable and reliable operation of the system.
Microprocessors with bidirectional reset pins can contend with the STWD100NYWY3F watchdog output, WDO. For example, if the WDO output is driven high and the micro wants to pull it low, signal contention is the result. To prevent this from occurring, connect a 4.7 kΩ resistor between the WDO output and the microprocessors reset I/O as in the following figure:
Here are some ways to prevent system failure:
1. Monitoring and logging: We can perform strict monitoring and logging. With the built-in monitoring mechanism, the watchdog timer is able to continuously track the operating status of the system and immediately log relevant information when any abnormal behavior is detected. This kind of logging not only helps to detect system failures in time, but also provides valuable data support for subsequent troubleshooting and repair.
2. Testing and verification: Before deploying the system, developers can conduct sufficient testing and verification work to ensure that the watchdog timer functions properly and as expected. This includes testing the timer's response time, reset mechanism, and interactions with other system components to ensure that the system is able to respond correctly and trigger the appropriate reset operation under various abnormal conditions.
3. Periodic dog feeding: In the program, the developer can set up a mechanism to periodically send signals to the watchdog timer to indicate that the system is operating normally. This dog feeding operation ensures that the timer will not mistakenly believe that the system has failed and trigger unnecessary reset operations because it has not received a signal for a long time. Through a reasonable dog feeding strategy, we can ensure that the system will not be interfered with during normal operation, and will be able to get a timely response when encountering a fault.
4. Properly configure the watchdog timer: We need to make sure that the watchdog timer's timeout is properly configured according to the system's needs. Setting the timeout too long may cause the system to be unable to respond in time when a fault occurs, while setting it too short may cause the reset operation to be triggered by mistake.
5. Correctly handle abnormal situations: When writing the program, developers need to fully consider the various abnormal situations that may occur in the system, and write the corresponding error handling and exception recovery mechanisms. When the system encounters a serious fault, we should be able to trigger the watchdog reset operation in time to avoid further expansion of the fault or more serious consequences.
Frequently Asked Questions
1. What is a watchdog in microcontroller?
A watchdog timer (WDT) is a timer that monitors microcontroller (MCU) programs to see if they are out of control or have stopped operating. It acts as a “watchdog” watching over MCU operation.
2. What is WDI watchdog?
The input is used to clear the internal watchdog timer periodically within the specified timeout period, twd. While the system is operating correctly, it periodically toggles the watchdog input, WDI.
3. In what fields is STWD100NYWY3F used?
STWD100NYWY3F is mainly used in electronic equipment, automotive electronics, medical equipment and other fields where temperature measurement and system failure prevention are required. Its high-precision measurement capabilities, small package, temperature stability and low noise output make it widely used in these fields.
4. What are the main functions of STWD100NYWY3F?
STWD100NYWY3F is a watchdog timer. Its main function is to monitor the operating status of the system and promptly output an alarm signal when a system fault is detected to prevent the system from falling into an unrecoverable state due to faults, thereby ensuring the stability and stability of the system. reliability.
