Analog Devices Inc./Maxim Integrated MAX6824RUK+

Overview

MAX6824RUK+ from Maxim Integrated is a low-voltage microprocessor supervisory IC in 5-pin SOT23 package, combining voltage monitoring (2.63V 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 MAX6824RUK+ datasheet, MAX6824RUK+ pinout, MAX6824RUK+ application, or MAX6824RUK+ equivalent, this page delivers verified circuit role, exact reset threshold, watchdog timing, dual-reset behavior, and validated alternatives for critical µP monitoring designs.

Technical Context

The MAX6824RUK+ implements a dual-output supervisory architecture: one active-low push-pull RESET and one active-high push-pull RESET, both asserted synchronously during VCC undervoltage, manual trigger, or watchdog timeout. Its internal watchdog timer clears on any WDI edge and times out after 1.6s if no transition occurs.

Reset assertion is guaranteed valid down to VCC = +1.0V, with 140ms minimum timeout delay and ±3% threshold accuracy over –40°C to +125°C. The device requires no external components and features immunity to short negative VCC transients up to 20µs at 100mV overdrive.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, surface-mount, RoHS-compliant (indicated by "+" suffix), footprint compatible with land pattern 21-0057.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6824RUK+, MAX6822RUK+ offers reduced functionality (single open-drain output) but lower cost, while MAX6316HUT46D3+ provides identical form factor and watchdog but targets higher-voltage rails - neither matches the dual-push-pull, 2.63V precision, and ultra-low-VCC operation of MAX6824RUK+.

Availability

MAX6824RUK+ is available at Aetrix Electronics and suitable for set-top boxes, embedded controllers, and portable/battery-powered equipment requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX6824RUK+ 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 communications applications, with emphasis on reliability and integration.

The MAX6821–MAX6825 family was engineered specifically for low-voltage µP supervision in space-constrained, battery-sensitive, and thermally demanding systems - delivering integrated voltage monitoring, watchdog, and dual-reset functionality in 5-pin SOT23.

FAQ

What is the exact reset threshold voltage of the MAX6824RUK+?

The MAX6824RUK+ has a factory-trimmed reset threshold of 2.63V ±3% over –40°C to +125°C. This value is confirmed in the Threshold Suffix Guide (suffix "R") and Electrical Characteristics table, where VTH is specified as 2.53V (min) to 2.72V (max) across temperature. The threshold applies to VCC monitoring and triggers reset assertion when supply voltage falls below this level.

Does the MAX6824RUK+ include a manual reset input (MR)?

No, the MAX6824RUK+ does not include a manual reset input. Per the Selector Guide and Pin Description, MAX6824 supports watchdog input (WDI) and dual push-pull reset outputs (RESET and RESET), but omits MR - unlike MAX6821/MAX6822/MAX6823/MAX6825. This is a deliberate functional differentiation within the family, confirmed in the "Functions Offered" table on page 8 of the datasheet.

What are the key differences between RESET and RESET outputs on the MAX6824RUK+?

On the MAX6824RUK+, RESET is an active-low push-pull output that goes low during fault conditions, while RESET is an active-high push-pull output that goes high under the same conditions. Both share identical timing (140ms min timeout) and trigger simultaneously on VCC drop, watchdog timeout, or WDI stall. Their complementary polarity enables direct interfacing with µPs or FPGAs requiring either reset logic level without external inversion.

Can the MAX6824RUK+ operate reliably at VCC = +1.1V?

Yes, the MAX6824RUK+ guarantees correct reset output state down to VCC = +1.0V, as explicitly stated in the General Description and Electrical Characteristics. At +1.1V, both RESET and RESET outputs remain fully functional and meet VOL/VOH specifications per datasheet tables - enabling fail-safe operation during severe brownout or battery discharge scenarios where other supervisors would lose reset validity.

How is the watchdog timer cleared on the MAX6824RUK+?

The watchdog timer on the MAX6824RUK+ is cleared by any rising or falling edge on the WDI pin - not by level, but by transition. As documented in the Detailed Description and Pin Description, the internal timer resets on each WDI toggle, and remains cleared while reset is asserted. If WDI is left unconnected, the internal driver pulses low-high-low every ~1.4s, preventing timeout; however, for deterministic control, firmware must actively toggle WDI within the 1.6s window.