Smart Reset Timer for sequenced power-up and brown-out supervision
The STM6520AQRRDG9F from STMicroelectronics is a Smart Reset™ timer — a programmable supervisory IC that generates a reset signal with an adjustable timeout period after the monitored supply crosses its threshold. It offers both active-high and active-low reset outputs, configurable as open drain or push-pull, so it can interface with a wide range of SoC reset inputs without external level translation. The timeout is adjustable via an external capacitor, letting you tailor the reset pulse width to the power-up sequencing requirements of FPGAs, MCUs, or mixed-voltage systems. The device operates over -30°C to 85°C, suiting it for industrial control panels, base station equipment, and outdoor telecom enclosures where the board temperature stays within that range.
Output configuration and reset polarity — what to watch on the BOM
Because the reset output can be either open drain or push-pull, the BOM pull-up resistor is conditional. If you configure the output as open drain, a pull-up to the appropriate rail is required; push-pull mode eliminates that resistor and provides a rail-to-rail drive. The dual active-high/active-low polarity means the same part can serve a processor that expects a logic-high reset and one that expects a logic-low, simplifying inventory across different board designs.
Package and footprint — 8-TDFN (2x2 mm)
Housed in an 8-TDFN package measuring 2x2 mm, the STM6520AQRRDG9F occupies minimal board area. The small footprint is a fit for space-constrained designs like handheld instruments or compact sensor nodes.
It carries ROHS3 compliance, so it meets current environmental requirements for EU and global markets.