Analog Devices Inc./Maxim Integrated MAX6824MUK+

Overview

MAX6824MUK+ from Maxim Integrated is a low-voltage microprocessor supervisory circuit in 5-pin SOT23 package, combining voltage monitoring (4.38V threshold), watchdog timer (1.6s timeout), and dual push-pull reset outputs (RESET and RESET). It asserts reset during power-up, brownout, or software hang, with guaranteed operation down to VCC = +1.0V - used in set-top boxes, embedded controllers, and portable battery-powered equipment.

For engineers reviewing the MAX6824MUK+ datasheet, MAX6824MUK+ pinout, MAX6824MUK+ application, or MAX6824MUK+ equivalent, this page delivers verified pin functions, exact reset threshold (4.38V), watchdog timing behavior, dual active-high/active-low reset coordination, and real-world substitution guidance for µP supervision in industrial and portable systems.

Technical Context

The MAX6824MUK+ integrates a precision voltage detector with ±2.5% threshold accuracy over –40°C to +125°C, a 1.6s watchdog timer cleared by WDI edge transitions, and two independent push-pull reset outputs - one active-low (RESET), one active-high (RESET) - enabling direct interface to bidirectional or polarity-specific µP reset inputs without external logic. Its internal 50kΩ MR pullup eliminates need for external components.

Reset assertion occurs when VCC falls below 4.38V, MR is pulled low, or WDI remains static beyond 1.6s; reset remains asserted for ≥140ms after recovery. The device operates across VCC = +1.2V to +5.5V and guarantees valid reset states down to VCC = +1.0V, making it suitable for ultra-low-voltage brownout detection in battery-backed systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (U5-1 outline), RoHS-compliant, surface-mount, footprint compatible with industry-standard 0.95mm pitch land pattern (Maxim land pattern no. 21-0057).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar µP supervision applications.

Compared with MAX6824MUK+, MAX6822MUK+ offers open-drain flexibility at the cost of external component dependency, while MAX6315US43D3+ reduces feature set to basic voltage monitoring - MAX6824MUK+ uniquely delivers dual push-pull reset coordination and integrated watchdog in a 5-pin SOT23.

Availability

MAX6824MUK+ is available at Aetrix Electronics and suitable for set-top boxes, embedded controllers, and portable/battery-powered equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6824MUK+ 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 industrial, computing, and consumer applications, with emphasis on reliability, integration, and low-power operation.

The MAX6821–MAX6825 family was engineered specifically for space-constrained µP supervision - delivering voltage monitoring, watchdog, and reset generation in a 5-pin SOT23, targeting portable, embedded, and instrumentation systems.

FAQ

What is the exact reset threshold voltage for MAX6824MUK+?

The MAX6824MUK+ has a factory-trimmed reset threshold of 4.38V, with ±2.5% tolerance over –40°C to +125°C. This value is confirmed in the Threshold Suffix Guide (suffix "M") and Electrical Characteristics table. The MAX6824MUK+ asserts reset when VCC falls below this threshold and holds reset for ≥140ms after VCC rises above it. This precise threshold ensures compatibility with +4.5V system rails while providing noise margin.

Does MAX6824MUK+ include a manual reset input (MR)?

No, the MAX6824MUK+ does not include a manual reset input. Per the Selector Guide and Pin Description, MR is present on MAX6821/MAX6822/MAX6823/MAX6825 but omitted in MAX6824. The MAX6824MUK+ relies solely on VCC monitoring and watchdog-triggered reset. Its pin 3 is WDI, not MR - confirmed by top-view diagrams and functional block diagrams in the datasheet.

What are the functions of the two reset outputs on MAX6824MUK+?

The MAX6824MUK+ provides two independent push-pull reset outputs: pin 1 is RESET (active-low), and pin 4 is RESET (active-high). When a fault occurs (VCC < 4.38V or watchdog timeout), RESET goes low and RESET goes high simultaneously. This dual-polarity capability allows direct connection to µPs requiring either signal polarity without external inverters or pull-up resistors - a key differentiator versus single-output supervisors.

How does the watchdog timer on MAX6824MUK+ operate?

The MAX6824MUK+ watchdog timer has a nominal timeout of 1.6s. It is cleared only by a rising or falling edge on WDI (pin 3); static high or low states cause timeout and reset assertion. While reset is active, the timer remains cleared. The MAX6824MUK+ does not require continuous toggling - a single edge within each 1.6s window suffices. WDI can be left unconnected to disable the watchdog, as its internal driver prevents spurious timeouts.

Is MAX6824MUK+ compatible with 1.8V or 2.5V supply rails?

Yes, the MAX6824MUK+ operates across VCC = +1.2V to +5.5V and guarantees valid reset output states down to VCC = +1.0V. Although its 4.38V threshold targets +4.5V systems, its wide supply range allows use in multi-rail systems - e.g., monitoring a 4.38V auxiliary rail while powered from a separate 1.8V or 2.5V domain. However, VCC must meet minimum operating voltage for the selected threshold variant; the MAX6824MUK+ is rated for VCC ≥ +1.2V across full temperature range.