Analog Devices Inc./Maxim Integrated MAX6827SUT+

Overview

MAX6827SUT+ from Maxim Integrated is a dual ultra-low-voltage microprocessor supervisory circuit in 6-pin SOT23 package, designed to monitor primary supply (VCC) and user-adjustable secondary input (RESET IN), with manual reset (MR), watchdog timer (WDI), and push-pull active-high RESET output. It asserts reset when VCC falls below 2.93V (S-suffix), RESET IN drops below 0.63V, MR is pulled low, or WDI times out after 1.6s - ensuring reliable power-up/brownout protection for battery-powered embedded systems.

For engineers reviewing the MAX6827SUT+ datasheet, MAX6827SUT+ pinout, MAX6827SUT+ application, or MAX6827SUT+ equivalent, key selection criteria include its 2.93V VCC threshold (±3% over –40°C to +125°C), 140ms minimum reset timeout, guaranteed reset validity down to VCC = +1.2V, and compatibility with 1.8V–3.6V primary supply ranges in portable and multivoltage systems.

Technical Context

The MAX6827SUT+ integrates two independent voltage monitors: one factory-trimmed for VCC (2.93V nominal), and one high-impedance comparator for RESET IN (0.63V internal reference). Its watchdog timer clears on any WDI edge and triggers reset if no transition occurs within 1.6s (min 1.12s, max 2.6s over temperature).

Reset assertion is synchronized across all fault conditions (VCC undervoltage, RESET IN undervoltage, MR low, WDI timeout); the push-pull RESET output drives high during reset and returns low afterward, with VOH ≥ 0.8×VCC at ISOURCE = 200µA and VOL ≤ 0.3V at ISINK = 1.2mA - enabling direct interface with 1.8V/2.5V/3.3V µP reset inputs without external pullups.

Key Specifications

Pinout & Package

Package: 6-pin SOT23 (U6+1 outline, land pattern 90-0175), RoHS-compliant, surface-mount.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6826SUT+ and MAX6828SUT+, the MAX6827SUT+ uniquely delivers active-high push-pull RESET, eliminating external components for 3.3V µP interfaces while maintaining identical supervision accuracy, watchdog reliability, and low-power operation - making it optimal for space-constrained, single-supply embedded designs.

Availability

MAX6827SUT+ is available at Aetrix Electronics and suitable for portable/battery-powered equipment, embedded controllers, intelligent instruments, and critical µP monitoring requiring stable component supply across automotive-grade temperature ranges.

Supply support for MAX6827SUT+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in analog and mixed-signal ICs for power, sensing, and interface applications.

The MAX6826–MAX6831 family was designed specifically for ultra-low-voltage, dual-rail microprocessor supervision in space- and power-constrained systems - delivering integrated reset, watchdog, and manual reset in sub-1mm² SOT23 packages.

FAQ

What is the exact VCC reset threshold voltage for MAX6827SUT+ and how stable is it over temperature?

The MAX6827SUT+ has a nominal VCC reset threshold of 2.93V, with guaranteed limits of 2.83V (min) to 3.02V (max) over the full –40°C to +125°C operating range. Its temperature coefficient is 60ppm/°C, resulting in ≤15mV total drift across temperature - sufficient for stable 3.3V rail supervision without calibration.

Does MAX6827SUT+ support monitoring a 1.2V core supply, and how is it configured?

Yes, MAX6827SUT+ supports 1.2V core monitoring via its RESET IN pin using an external resistor divider. With a fixed 0.63V internal reference, a 1.2V supply is sensed by setting R1/R2 ratio to ~0.90 (e.g., R1 = 90.9kΩ, R2 = 100kΩ), yielding trip point VMONITOR = 0.63V × (1 + R1/R2) ≈ 1.2V - confirmed in the device's Adjustable Reset Thresholds section.

What is the watchdog timeout behavior of MAX6827SUT+, and how does it interact with manual reset?

The MAX6827SUT+ watchdog timeout is nominally 1.6s, varying from 1.12s to 2.6s over temperature. The timer clears on any WDI edge (rising or falling) and also resets automatically when MR is asserted or RESET is active - ensuring coordinated recovery during manual intervention or power faults.

Can MAX6827SUT+ operate reliably at VCC = 1.5V, and what happens to RESET output below that?

Yes, MAX6827SUT+ is fully specified down to VCC = +1.2V, with guaranteed RESET output functionality (VOH ≥ 0.8×VCC, VOL ≤ 0.3V). Below 1.2V, the device ceases operation and RESET becomes undefined; however, its 140ms timeout ensures µP remains held in reset until VCC rises above threshold - preventing partial initialization.

How does the MR input of MAX6827SUT+ handle noise, and is external filtering required?

The MAX6827SUT+ MR input includes 100ns glitch rejection and an internal 50kΩ pullup, allowing direct CMOS-level connection without debounce. In noisy environments or long-trace layouts, a 0.1µF capacitor from MR to GND adds immunity - per the Applications Information section - but is not mandatory for typical PCB implementations.