ST SR1UARU

The Smart ResetTM devices 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 pushbutton 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 tsRc causes a hard reset of the processor through the reset output. The SR1 has one Smart Reset input (SR（overline）) with preset delayed Smart Reset setup time (tsRc). The reset output (RST（overline）) is asserted after the Smart Reset input is held active for the selected tsRc delay time. The RST（overline） output remains asserted either until the SR（overline） input 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 (ie.factory-programmed). The device fully operates over a broad VCC range from 2.0V to 5.5V

• Operating voltage range 2V to 5.5V
• Low supply current 1 μA
• Integrated test mode
• Single Smart ResetTM push-button input with fixed extended reset setup delay (tsRc) from 0.5 s to 10 s in 0.5 s steps (typ.), option with internal input pull-up resistor
• Push-button controlled reset pulse duration
• Option 1: fully push-button controlled, no fixed or minimum pulse width guaranteed
• Option 2: defined output reset pulse duration (tREc), factory-programmed
• Single reset output – Active low or active high
• Push-pull or open drain with optional pullup resistor
• Fixed Smart Reset input logic voltage levels
• Operating temperature: -40 °C to +85 °C
• UDFN6 package 1.00 mm×1.45 mm
• ECOPACK (RoHS compliant, HalogenFree)

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