Analog Devices Inc./Maxim Integrated MAX6731AUTTD3+T

Overview

MAX6731AUTTD3+T from Maxim Integrated is a single-voltage microprocessor supervisor IC with push-pull active-low reset output, manual reset input, and independent push-pull watchdog output. It monitors VCC1 at factory-set +3.075V threshold (suffix "T"), provides 140–280ms reset timeout (suffix "D3"), operates from -40°C to +125°C, and draws only 14µA typical supply current at +3.6V - used in telecom power sequencing and industrial controller brownout protection.

For engineers reviewing the MAX6731AUTTD3+T datasheet, MAX6731AUTTD3+T pinout, MAX6731AUTTD3+T application, or MAX6731AUTTD3+T equivalent, this page delivers verified circuit role, exact reset thresholds, watchdog timing behavior, SOT23-6 package mapping, and validated alternative parts for multivoltage system design and qualification.

Technical Context

The MAX6731AUTTD3+T implements a dual-mode watchdog timer: a 35s minimum startup delay after reset enables full system initialization, followed by a 1.12s minimum normal-mode timeout period triggered by WDI edge transitions. Its internal comparator guarantees valid reset assertion down to VCC1 = +0.8V, with 20ppm/°C tempco and 0.5% hysteresis on the +3.075V VCC1 threshold.

This device integrates a 50kΩ internal MR pullup, supports CMOS-level manual reset triggering, and features immunity to sub-100ns VCC transients. The push-pull RST and WDO outputs eliminate external pullups and support direct interfacing with bidirectional µP reset pins when used with a 10kΩ series resistor.

Key Specifications

Pinout & Package

MAX6731AUTTD3+T is housed in a 6-pin SOT23-6 package (package code U6-1), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and RoHS-compliant lead-free finish (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6730AUTTD3+T, the MAX6731AUTTD3+T offers faster reset release and simpler layout via push-pull RST, while TPS3808G33DBVR reduces cost and footprint but sacrifices critical watchdog and manual reset capabilities required in safety-critical embedded systems.

Availability

MAX6731AUTTD3+T is available at Aetrix Electronics and suitable for telecom power sequencing, industrial PLC controllers, and automotive ADAS camera modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6731AUTTD3+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6730A–MAX6735A family was designed specifically for multivoltage microprocessor supervision in harsh environments, integrating precise reset thresholds, dual-mode watchdog timers, and robust ESD/transient immunity into ultra-small SOT23 packages.

FAQ

What is the exact VCC1 reset threshold voltage for MAX6731AUTTD3+T?

The MAX6731AUTTD3+T has a factory-set VCC1 reset threshold of +3.075V nominal, with ±75mV tolerance over the full -40°C to +125°C operating range. This value is defined by the "T" suffix in the part number and confirmed in Table 1 of the official datasheet. The threshold exhibits 20ppm/°C tempco and 0.5% hysteresis relative to typical value.

Does MAX6731AUTTD3+T include a manual reset input?

Yes, MAX6731AUTTD3+T includes an active-low manual reset input (MR) on Pin 4. It features an internal 50kΩ pullup resistor to VCC1, accepts standard CMOS logic levels (VIL ≤ 0.3×VCC1, VIH ≥ 0.7×VCC1), and asserts RST for the full reset timeout period after MR is released. MR pulse width must exceed 1µs, with 100ns glitch rejection.

What is the watchdog timeout behavior of MAX6731AUTTD3+T?

MAX6731AUTTD3+T uses a dual-mode watchdog: 35s minimum startup delay after any reset event (power-up, brownout, or MR), followed by 1.12s minimum normal-mode timeout after the first valid WDI edge. WDO asserts low if no WDI transition occurs within the active timeout window, and deasserts immediately when a valid edge is detected.

What package type and dimensions does MAX6731AUTTD3+T use?

MAX6731AUTTD3+T uses a 6-pin SOT23-6 package (U6-1), with body dimensions of 2.9mm × 1.6mm × 1.1mm and gull-wing lead form. It is RoHS-compliant and lead-free, indicated by the "+T" suffix. Pin 1 is marked with a dot, and the package meets JEDEC MO-178 variation BA mechanical standards.

How does the reset timeout period D3 translate to actual timing for MAX6731AUTTD3+T?

The "D3" suffix in MAX6731AUTTD3+T specifies a reset timeout period of 140ms (minimum) to 280ms (maximum), as defined in Table 2 of the datasheet. This duration begins when all monitored conditions (VCC1 ≥ +3.075V, MR high) are satisfied and determines how long RST remains asserted after fault clearance - ensuring reliable processor initialization.