Analog Devices Inc./Maxim Integrated MAX6826TUT+T

Overview

MAX6826TUT+T from Maxim Integrated is a dual ultra-low-voltage microprocessor supervisory IC in 6-pin SOT23 package, monitoring primary VCC (3.08V threshold) and user-adjustable secondary voltage down to 0.63V via RESET IN pin, with 140ms min reset timeout, manual reset input, and 1.6s watchdog timer - used in portable battery-powered equipment for reliable power-on reset and brownout protection.

For engineers reviewing the MAX6826TUT+T datasheet, MAX6826TUT+T pinout, MAX6826TUT+T application, or MAX6826TUT+T equivalent, this page delivers verified circuit role, exact threshold values, reset timing behavior, watchdog interaction logic, and real-world substitution guidance - all confirmed against Maxim's official Rev 3 datasheet (19-1867, 7/2014).

Technical Context

The MAX6826TUT+T integrates two independent voltage monitors: one factory-trimmed at 3.08V (±3% over -40°C to +125°C) for VCC, and a high-impedance RESET IN comparator with 0.63V typical threshold for external resistor-divider–based secondary voltage monitoring. It asserts an active-low push-pull RESET output when either monitored voltage falls below threshold, MR is pulled low, or WDI fails to toggle within 1.6s.

Reset remains asserted for ≥140ms after recovery, with propagation delays under 20µs (VCC→RESET) and 15µs (RESET IN→RESET). The device operates down to VCC = +1.0V and draws only 30µA max ICC over full temperature range, enabling use in ultra-low-power embedded systems requiring guaranteed reset validity during deep brownout.

Key Specifications

Pinout & Package

Package: 6-pin SOT23 (U6+1 outline, land pattern 90-0175), RoHS-compliant lead-free (indicated by "+T" suffix), -40°C to +125°C operating range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6826TUT+T, MAX6827TUT+T offers identical monitoring accuracy but reversed reset polarity, while TPS3808G30DBVR sacrifices dual monitoring and watchdog capability for lower cost and smaller footprint - neither is pin-compatible, and both require schematic and firmware review for integration.

Availability

MAX6826TUT+T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, embedded controllers, and intelligent instruments requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for MAX6826TUT+T 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) designs precision analog and mixed-signal ICs for power, sensing, and interface applications, with emphasis on high-reliability, low-power solutions.

The MAX6826–MAX6831 family was engineered specifically for dual-rail microprocessor supervision in space-constrained, battery-operated, and industrial systems - delivering factory-trimmed thresholds, integrated watchdog, and guaranteed operation down to 1.0V VCC.

FAQ

What is the exact VCC reset threshold voltage for MAX6826TUT+T across temperature?

The MAX6826TUT+T has a factory-trimmed VCC reset threshold of 3.08V, with tolerance of ±3% over the full -40°C to +125°C operating range - specified as min 2.97V and max 3.17V. This value is confirmed in the Electrical Characteristics table (page 2 of Rev 3 datasheet) and applies exclusively to the "T" suffix variant. The MAX6826TUT+T does not monitor VCC2; its secondary monitoring is performed via the RESET IN pin.

Does MAX6826TUT+T support monitoring a secondary voltage, and how is it implemented?

Yes, MAX6826TUT+T supports secondary voltage monitoring via its RESET IN pin, which features a fixed 0.63V (typ) internal comparator threshold. To monitor voltages above 0.63V - such as 1.8V or 2.5V - connect an external resistor divider between the target rail and GND, with the midpoint fed to RESET IN. The trip point is calculated as V_MONITOR = 0.63V × (R1 + R2)/R2. This method is explicitly documented in Figure 5 and Applications Information section of the MAX6826TUT+T datasheet.

What type of RESET output does MAX6826TUT+T provide, and what are its drive capabilities?

MAX6826TUT+T provides an active-low push-pull RESET output. It can sink up to 3.2mA at VCC ≥ 4.25V while maintaining VOL ≤ 0.4V, and sources current when deasserted (VOH ≥ 0.8 × VCC at ISOURCE = 200µA). Unlike open-drain variants (e.g., MAX6828), it requires no external pull-up resistor - simplifying PCB layout and ensuring fast rise/fall times in noise-sensitive environments.

How does the watchdog timer function in MAX6826TUT+T, and what is its timeout period?

The MAX6826TUT+T watchdog timer triggers a reset if the WDI pin remains static (high or low) for longer than its timeout period, nominally 1.6s (range 0.8s–2.6s over temperature). The timer clears on any WDI edge (rising or falling), MR assertion, or RESET assertion. Pulse width as short as 50ns is recognized. Leaving WDI unconnected disables the watchdog, as internal circuitry services the timer every ~1.4s - a behavior confirmed in the Watchdog Input section (page 8) of the datasheet.

Is MAX6826TUT+T guaranteed to operate correctly at VCC = +1.0V, and what does that mean for system design?

Yes, MAX6826TUT+T is fully specified and guaranteed to assert valid RESET output down to VCC = +1.0V, as stated in the General Description and Absolute Maximum Ratings sections. This means the device continues to monitor VCC and RESET IN, detect threshold violations, and drive the RESET pin with defined logic levels even during severe brownout - enabling robust fail-safe behavior in battery-powered systems where VCC may dip below 1.2V during cold-cranking or end-of-life discharge.