STMicroelectronics

The SPT01-335 is specifically designed for the protection of 24 V proximity sensors. It implements the reverse polarity and the overvoltage protection of the sensor power supply and the power switch overvoltage protection. It provides a very compact and flexible solution offering two connections for PNP or NPN sensors as shown in and Figure 9. Thanks to high performance ST technology, the SPT01-335 protects the proximity sensor to the highest level compliant with IEC 61000-4-2, IEC 61000-4-4 and IEC 60947-5-2 / IEC 61000-4-5 standards.

The SPT02 is specifically designed for the protection of 24 V proximity sensors. It implements the reverse polarity and the overvoltage protection of the sensor power supply and the power switch overvoltage protection. It provides a very compact and flexible solution. Thanks to high performance ST technology, the SPT02 protects the proximity sensor to the highest level compliant with IEC 61000-4-2, IEC 61000-4-4 and IEC 61000-4-5 standards.

The Smart ResetTMdevices provide a useful feature which ensures that inadvertent short reset push-button closures do not cause system resets. This is done by implementing an extended Smart Reset input delay time (tSRC), which ensures a safe reset and eliminates the need for a specific dedicated reset button. This reset configuration provides versatility and allows the application to distinguish between a software generated interrupt and a hard system reset. When the input push-button is connected to the microcontroller interrupt input, and is closed for a short time, the processor can only be interrupted. If the system still does not respond properly, continuing to keep the push-button closed for the extended setup time tSRCcauses a hard reset of the processor through the reset output. The SR1 has one Smart Reset input (SR) with preset delayed Smart Reset setup time (tSRC). The reset output (RST) is asserted after the Smart Reset input is held active for the selected tSRCdelay time. TheRSToutput remains asserted either until theSRinput goes to inactive logic level (i.e. neither fixed nor minimum reset pulse width is set) or the output reset pulse duration is fixed for tREC(i.e. factory-programmed). The device fully operates over a broad VCCrange from 2.0 V to 5.5 V.