STMicroelectronics STM6522

The Smart Reset™ devices provide a useful feature that ensures that inadvertent short reset push-button closures do not cause system resets as the extended Smart Reset™ delay setup periods are implemented. Once the valid Smart Reset™ input levels and setup delay are met, the device generates an output reset pulse for a fixed timeout period (tREC). The typical application hookup shows that either a single Smart Reset™ input, or both reset inputs can be connected to the applications interrupt and control both the interrupt pin and the hard reset functions. If the push-button is closed for a short time, the processor is only interrupted. If the system still does not respond properly, holding the push-button(s) for the extended setup time (tSRC) causes a hard reset of the processor. The Smart Reset™ feature helps significantly increase system stability and eliminates the need for a dedicated reset button. The STM65xx family of Smart Reset™ devices consists of low-current microprocessor reset circuits targeted at applications such as MP3 players, portable navigation or mobile phones, generally any application that requires delayed reset push-button(s) response for improved system stability. The devices in the STM65xx Smart Reset™ family include various combinations of useful features for the targeted applications. The STM6522 has two combined Smart Reset™ inputs (SR0 and SR1) with delayed reset setup time (tSRC) programmed by an external capacitor on the SRC pin.

Key features

• Dual Smart Reset™ push-button inputs with capacitor-adjustable extended reset setup delay (tSRC)
• No power-on reset
• Dual RST output, active-low, open-drain
• Fixed Smart Reset™ input logic voltage levels
• Broad operating voltage range 1.65 V to 5.5 V, inactive reset output levels valid down to 1.0 V
• Low supply current (1.5 μA)
• Operating temperature: industrial grade -40 °C to +85 °C
• TDFN8 package: 2 mm x 2 mm x 0.75 mm
• RoHS compliant

Applications

• Mobile phones, smartphones
• e-books
• MP3 players
• Games
• Portable navigation devices
• Application requiring delayed reset push-button(s)