STMicroelectronics SR2 6-Pin Smart Reset™ Switch

STMicroelectronics SR2 6-Pin Smart Reset™ Switch is designed to ensure that inadvertent short reset push-button closures do not cause system resets. This is done by implementing extended Smart Reset input delay time (t_SRC) and combined push-button inputs, which together 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 are connected to microcontroller interrupt inputs, and are 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 t_SRC causes a hard reset of the processor through the reset output.

The SR2 has two combined delayed Smart Reset inputs (SR0, SR1) with preset delayed Smart Reset setup time (t_SRC). The reset output is asserted after both of the Smart Reset inputs were held active for the selected t_SRC delay time. Depending on selected option the RST output remains asserted either until at least one SR input goes to inactive logic level or the output reset pulse duration is fixed for t_REC. The reset output, RST, is active low or active high, push-pull or open drain with optional pull-up resistor. The device fully operates over a broad V_CC range 1.65V to 5.5V. Below 1.575V the inputs are ignored and outputs are deasserted; the deasserted reset output levels are then valid down to 1.0V.

The STMicroelectronics SR2 6-Pin Smart Reset Switch is offered in a 1.6mm x 1.3mm UDFN6 package.

Features

1.65V to 5.5V operating voltage
Low 1.5µA supply current
Integrated test mode
Dual Smart Reset push-button inputs with fixed extended reset setup delay (t_SRC) from 0.5s to 10s in 0.5s steps (typ.), option with internal 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 (t_REC), factory-programmed

No power-on reset
Single reset output
- Active low or active high
- Push-pull or open drain with optional pull-up resistor
Fixed Smart Reset input logic voltage levels
-40°C to +85°C operating temperature
1.6mm x 1.3mm UDFN6 package
ECOPACK2 (RoHS compliant, Halogen-Free)