What this supervisor does on your board
The MAX6833VXRD0+T is a simple reset/power-on reset supervisor from Analog Devices, built to hold a processor in reset until the monitored supply rail is stable. It watches a single voltage rail with a threshold of 1.575V and, once the rail crosses that threshold cleanly, waits a minimum of 140ms before releasing the reset line. The output is active-high, push-pull, totem-pole — meaning it drives the reset pin high when the rail is out of tolerance and pulls low when the rail is good. That polarity matters: if your processor expects an active-low reset, this part won't work without an inverter. The whole thing fits in a three-pin SC-70-3 package, surface-mount, and runs across the -40°C to 85°C industrial temperature range. Typical use is on an MCU or MPU board where you need a clean, glitch-free startup sequence and don't want to rely on an RC delay.
1.575V threshold — which rail it watches
The 1.575V threshold is the voltage at which the part decides the rail is good. It monitors a single voltage rail.
140ms reset timeout — why that number
The 140ms minimum reset timeout is the time the part holds the reset line asserted after the rail crosses the 1.575V threshold. That's long enough for most oscillators and PLLs to stabilise before the processor fetches its first instruction. If your design uses a slow-starting regulator or a crystal with a long startup time, verify that 140ms is enough — some FPGAs and high-end MCUs need 200ms or more. The timeout is fixed; there's no external capacitor to adjust it.
Active-high output — get the polarity right
The reset output is active-high, push-pull. That means when the monitored rail is below threshold or during the timeout period, the output pin is driven high. When the rail is good and the timeout expires, the output goes low. Most processors expect an active-low reset (RESET#), so you'll need to invert the signal with a transistor or a logic gate, or pick a different supervisor with active-low output. If your processor has an active-high reset pin, this part connects directly.
Package and mounting — SC-70-3
The MAX6833VXRD0+T comes in a three-lead SC-70-3 package, which is the same footprint as SOT-323. It's surface-mount, so it reflows with standard lead-free profiles. The small size means it fits on tight boards, but the three pins are fine-pitch — verify your solder paste stencil aperture to avoid bridging.
Sourcing and lifecycle
The MAX6833VXRD0+T is listed as Active in production and ROHS3 compliant. No official replacement or second-source alternate is listed, but the part is available through independent distribution.