ST reset and supervisor ICs ensure that microcontrollers, processors, FPGAs, and digital ASICs always start and operate in known, safe conditions, even under demanding supply voltage and environmental constraints.
Product types
Our portfolio covers everything from single-voltage resets to highly integrated devices combining reset, watchdog, battery switchover, and tamper-detect functions.
Benefits
- Increased system reliability
- Guaranteed reset assertion under brown-out conditions
- Accurate voltage monitoring with tight, well-defined thresholds
- Safe startup and shutdown sequences for MCUs and digital devices
- Simplified power management
- Integrated reset generation, threshold voltage detection, and optional watchdog functions
- Reduced discrete component count and glue logic
- Consistent behavior over temperature and supply variations
- Optimized board space and cost
- Miniature SMD packages
- Low external component count
- Consistent behavior over temperature and supply variations
- Extended battery life and low-power operation
- Ultra-low quiescent current versions for battery-powered and IoT devices
- Minimal impact on overall system consumption
Questions and answers
- Why use reset and supervisor ICs?
They ensure correct power-up sequencing, continuously monitor supply voltage, and automatically recover from brownouts or software freezes, improving system robustness and perceived product quality. - What is the difference between a voltage detector and a reset IC?
Voltage detectors are simple threshold comparators with accurate hysteresis. Reset ICs add a defined minimum reset pulse width, ensuring the reset signal is held long enough for the MCU to reliably exit reset, providing noise immunity and compatibility with processors that require a guaranteed minimum assertion time. - Why use a standalone reset IC if my MCU already has one?
Standalone reset ICs operate independently of MCU low-power modes, are unaffected by slow supply-voltage rise times, offer tighter voltage thresholds than most integrated supervisors, cannot be disabled by runaway software, can monitor multiple rails simultaneously, and guarantee a reset pulse long enough for reliable startup regardless of MCU state. - Output options: push-pull vs. open-drain
Push-pull outputs deliver fast, rail-to-rail transitions with low static current but cannot be wire-OR'd with other reset sources. Open-drain outputs allow multiple reset sources to share a single reset line (wired-OR), at the cost of a pull-up resistor and slightly slower rise time. - Advanced options: backup power, watchdog, power-fail, security
Battery switchover ensures backup power during main-supply loss. Standalone watchdogs monitor code execution autonomously, independent of MCU state. Chip-enable gating and early power-fail signals protect memory and data from corruption during supply collapse. Security supervisors add tamper detection and alarm outputs. - Why use a standalone watchdog instead of the MCU's internal watchdog?
Standalone watchdogs offer several advantages that on-chip watchdogs cannot match:
- They cannot be disabled or reconfigured by runaway or malicious software
- They can provide longer or application-specific timeout windows that are not available in the MCU's internal timer
- They operate independently of MCU power modes, remaining active even when the processor is halted or in deep sleep
- They provide a deterministic, hardware-enforced safety net that does not depend on correct software configuration at startup