ST AN3261 Application Note - Dual Push-Button Smart Reset Devices with User_Adjustable Setup Delays
Summary
Enhance your system reliability with Smart Reset™ devices. This solution provides stable hardware resetting by requiring continuous press activation from dual or multiple input buttons, eliminating bulky physical reset holes. Developed for electronics engineers, this guide details the comprehensive features—including adjustable delays and voltage monitoring—and offers application diagrams that walk users through implementing robust, dependable power-on reset mechanisms in complex embedded systems.
Page 1 Text Content
AN3261
Application note
Dual push-button Smart Reset™ devices with user-adjustable setup delays
Introduction The Smart Reset™ family of devices consists of several products with a combination of features selected to best suit most typical applications. Their basic common feature is dual- button reset with setup delay that requires both input reset buttons to be continuously pressed for a defined period of time. This improves system stability compared to simple manual reset button devices and eliminates the need for a traditional reset access hole (e.g. two standard keys on the mobile phone keyboard can be used as Smart Reset™ inputs). Numerous additional features and device options are factory-programmed or can be implemented upon request. Common STM65xx Smart Reset™ family features include: Dual-button Smart Reset™ inputs VCC range 1.0 to 5.5 V (active-low output valid) Industrial operating temperature range –40 °C to +85 °C Space-saving TDFN8 package (2 mm x 2 mm x 0.75 mm) Ro HS compliance Differentiating features of the devices are: With or without Power-on Reset (POR) With or without VCC monitoring Independent battery monitoring feature with battery-low warning (STM6505 only) Input logic voltage levels: standard CMOS or fixed threshold Smart Reset™ output characteristics Defined reset pulse duration or push-button controlled (undefined) reset pulse duration Reset pulse duration: factory-programmed or capacitor-adjustable Smart Reset™ delay: tri-state / dual-state / capacitor-adjustable Open-drain or push-pull reset output Single or dual reset output
September 2010 Doc ID 17837 Rev 1 1/17
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Page Summary Contents For ST AN3261 Application Note - Dual Push-Button Smart Reset Devices with User_Adjustable Setup Delays
Manual Details
| Brand | Dual |
|---|---|
| Pages | 17 |
| File Size | 630.21 KB |
| Published | June 03, 2026 |
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Frequently Asked Questions
How does the Smart Reset feature improve system stability?
It requires both input reset buttons to be continuously pressed for a defined period of time, which enhances stability compared to simple manual button devices.
What are the operational voltage and temperature limits?
The V range is 1.0 to 5.5 V (active-low output valid), and it operates in an industrial temperature range from –40 °C to +85 °C.
Can I integrate this with a smartphone or existing keypad inputs?
Yes, standard keys, such as those on a mobile phone keyboard, can be utilized as Smart Reset™ input buttons.
How adjustable is the reset delay and pulse duration?
The Smart Reset delay can be tri-state/dual-state/capacitor-adjustable, and both the reset pulse duration and the overall delay period are configurable.