Single-channel voltage supervisor for 5 V rails
The MAX6711LEXS from Maxim Integrated is a simple reset/power-on reset IC that monitors a single voltage rail and asserts a reset signal when the supply drops below a 4.63 V threshold. It uses an active-low, push-pull output so no external pull-up resistor is needed. The reset timeout is a minimum of 140 ms, giving downstream devices enough time to stabilize after power-up. Rated for -40°C to 125°C, this part suits industrial control, automotive body electronics, and outdoor telecom gear where the ambient temperature can swing widely.
140 ms reset timeout — sizing the hold-up cap
The 140 ms minimum reset timeout gives the main regulator and oscillator time to settle before the processor starts executing code. If your design has a fast-starting regulator or you need a shorter watchdog window, this timeout may feel long; for most MCU-based systems it's a safe default that avoids race conditions at power-on.
Lifecycle and compliance note
However, it is RoHS non-compliant. That means it cannot be used in products sold into the EU or other regions that enforce RoHS restrictions without an exemption. For new designs requiring RoHS compliance, look at the lead-free version of this family — the MAX6711LEXS+T, for example, has the same electrical specs in a RoHS-compliant finish.
Package and footprint
Housed in a 4-pin SC-70 (SC-82A/SOT-343) surface-mount package, the MAX6711LEXS takes up minimal board area. The supplier device package is listed as SC-70-4.