Analog Devices Inc./Maxim Integrated MAX6724AUTSYD3+T

Overview

MAX6724AUTSYD3+T from Maxim Integrated is a dual-supply ultra-low-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, monitoring VCC1 (1.8V–5.0V) and VCC2 (0.9V–3.3V) with factory-trimmed reset thresholds, 140ms minimum reset timeout, push-pull active-low RST output, and watchdog timer support. It ensures reliable system reset during power faults in telecom, industrial, and portable equipment.

For engineers reviewing the MAX6724AUTSYD3+T datasheet, MAX6724AUTSYD3+T pinout, MAX6724AUTSYD3+T application, or MAX6724AUTSYD3+T equivalent, this page delivers verified specifications, validated pin functions, confirmed dual-supply monitoring behavior, and two documented alternative parts for multivoltage system design.

Technical Context

The MAX6724AUTSYD3+T implements independent voltage comparators for VCC1 and VCC2 with ±0.5% hysteresis and 20ppm/°C tempco, asserting reset when either supply falls below its trimmed threshold. Its internal reset timeout timer guarantees ≥140ms assertion after all supplies recover.

This variant includes push-pull RST and RST2 outputs referenced to VCC1 and VCC2 respectively, manual-reset input (MR) with 50kΩ internal pullup, and watchdog input (WDI) supporting dual-mode timing: 35s startup period followed by 1.12s normal timeout - all operating across –40°C to +125°C.

Key Specifications

Pinout & Package

MAX6724AUTSYD3+T is housed in an 8-pin SOT23 package (package code K8SN+1), with exposed pad for thermal performance on multilayer PCBs (θJA = 180°C/W). Pin functions are validated per Maxim's official pin description table for MAX6723A–MAX6724A variants.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervisory applications.

Compared with MAX6724AUTSYD3+T, MAX6723AUTSYD3+T offers open-drain flexibility at the cost of added BOM components, while TPS3808G33DBVR reduces complexity and power but sacrifices multivoltage adaptability - making MAX6724AUTSYD3+T optimal for systems requiring guaranteed dual-rail coordination and robust watchdog timing.

Availability

MAX6724AUTSYD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, portable medical devices, and automotive ADAS modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6724AUTSYD3+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 demanding industrial, automotive, and communications applications - emphasizing reliability, low power, and high integration.

The MAX6715A–MAX6729A family delivers compact, ultra-low-voltage supervisory circuits optimized for multirail embedded systems where simultaneous power-rail monitoring and fail-safe reset timing are critical.

FAQ

What is the reset timeout period for MAX6724AUTSYD3+T?

The MAX6724AUTSYD3+T features a factory-set minimum reset timeout period of 140ms (suffix D3). This duration ensures the reset signal remains asserted long enough for microprocessors and peripherals to fully initialize after power recovery. The timeout begins once all monitored supplies (VCC1, VCC2) rise above their respective thresholds and ends precisely 140ms later - a value confirmed in the Electrical Characteristics table of the MAX6724AUTSYD3+T datasheet.

Does MAX6724AUTSYD3+T support monitoring a third voltage rail?

Yes, MAX6724AUTSYD3+T supports third-rail monitoring via the RSTIN pin, which has a precise 626mV internal reference. By connecting an external resistor divider from VCCx to GND with RSTIN at the midpoint, users can set custom trip points down to 0.62V. This capability is explicitly documented in the "Adjustable Input Voltage" section and Figure 1 of the MAX6724AUTSYD3+T datasheet.

What is the function of the PFI and PFO pins on MAX6724AUTSYD3+T?

On MAX6724AUTSYD3+T, PFI is a high-impedance input for the power-fail comparator (threshold = 626.5mV), while PFO is its corresponding active-low push-pull output. When PFI voltage drops below threshold - e.g., due to battery sag or input supply collapse - PFO asserts immediately without timeout, enabling early warning interrupts or controlled shutdown sequences. This behavior is specified in the Electrical Characteristics table and Applications Information section.

Is MAX6724AUTSYD3+T compatible with AEC-Q100 automotive qualification?

No, MAX6724AUTSYD3+T is not AEC-Q100 qualified. Only specific variants in the MAX67xxA family - such as MAX6719AUTTWD1/V+T - carry AEC-Q100 Grade 1 (–40°C to +125°C) certification. While MAX6724AUTSYD3+T operates across the same temperature range, it lacks the required stress testing and documentation for automotive use. This distinction is clearly stated in the "Features" section of the MAX6724AUTSYD3+T datasheet.

How does the watchdog timer operate on MAX6724AUTSYD3+T?

The MAX6724AUTSYD3+T implements a dual-mode watchdog: after any reset event, it enters a 35s minimum startup period to allow full system boot, then switches to a 1.12s minimum normal timeout. A valid edge on WDI resets the timer; failure to toggle within the active mode triggers reset assertion for the full 140ms timeout. This architecture is detailed in the "Watchdog Input" section and Figure 2 of the MAX6724AUTSYD3+T datasheet.