Analog Devices Inc./Maxim Integrated MAX6731UTVD3+T

Overview

MAX6731UTVD3+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 (suffix VD), provides 140ms–280ms reset timeout (D3), consumes 14µA typical supply current, and operates from -40°C to +85°C in SOT23-6 package. It ensures reliable system boot and runtime supervision in embedded power management circuits.

For engineers reviewing the MAX6731UTVD3+T datasheet, MAX6731UTVD3+T pinout, MAX6731UTVD3+T application, or MAX6731UTVD3+T equivalent, this page delivers verified circuit role, exact reset thresholds, watchdog timing behavior, package mapping, and validated alternative options - all confirmed for the precise MAX6731UTVD3+T variant.

Technical Context

The MAX6731UTVD3+T implements a dual-mode watchdog timer: 35s minimum startup delay after reset, followed by 1.12s minimum normal-mode timeout. Its VCC1 reset comparator uses a precision internal reference with 20ppm/°C tempco and 0.5% hysteresis, guaranteeing valid reset assertion down to VCC1 = +0.8V.

It features a dedicated manual reset input (MR) with 50kΩ internal pullup, 1µs minimum pulse width, and 100ns glitch rejection. The push-pull RST output drives low to 0.3V at 1.2mA sink, while WDO operates identically - both fully specified across the full industrial temperature range.

Key Specifications

Pinout & Package

SOT23-6 package (6-pin, 1.6mm × 2.9mm, 0.95mm height), JEDEC MO-178AC compliant, RoHS-compliant lead(Pb)-free (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6730UTVD3+T, the MAX6731UTVD3+T eliminates external pullups and simplifies layout; compared with MAX6733UTVD3+T, it retains manual reset capability essential for serviceability - making MAX6731UTVD3+T the optimal choice for single-rail systems requiring both watchdog and user-initiated reset.

Availability

MAX6731UTVD3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, network router power management, medical handheld diagnostics, and POS terminal power sequencing requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6731UTVD3+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 industrial, communications, and computing applications, with expertise in power management and reliability-critical supervision.

The MAX6730–MAX6735 family delivers single/dual/triple-voltage µP supervisors with independent watchdog outputs, engineered specifically for robust system-level power integrity and fault recovery in harsh industrial and telecom environments.

FAQ

What is the exact VCC1 reset threshold voltage for MAX6731UTVD3+T?

The MAX6731UTVD3+T has a factory-set VCC1 reset threshold of +3.075V (falling edge), corresponding to the 'VD' suffix per Maxim's Reset Voltage Threshold Suffix Guide. This value is guaranteed across -40°C to +85°C with ±1.5% tolerance and 20ppm/°C tempco, ensuring consistent brownout detection in industrial applications.

Does MAX6731UTVD3+T support manual reset, and how is it implemented?

Yes, MAX6731UTVD3+T includes an active-low manual reset input (MR) with internal 50kΩ pullup to VCC1. Driving MR low for ≥1µs forces RST assertion for the full D3 timeout period (140–280ms). The input rejects <100ns glitches and accepts TTL/CMOS logic levels - enabling direct connection to pushbuttons or FPGA GPIO without external components.

What are the watchdog timing characteristics of MAX6731UTVD3+T?

MAX6731UTVD3+T features a dual-mode watchdog: 35s minimum startup delay after reset (to allow full system initialization), then 1.12s minimum normal-mode timeout. A rising or falling edge on WDI clears the timer; absence of edges for >1.12s asserts WDO low. WDI requires no external pullup and remains functional even when left unconnected.

Is MAX6731UTVD3+T compatible with bidirectional MCU reset pins?

Yes, but with caution: its push-pull RST output may cause contention with bidirectional reset I/O. Maxim recommends inserting a 10kΩ series resistor between RST and the MCU pin (per Figure 5 in the datasheet) to prevent logic conflict. For direct compatibility without resistors, open-drain alternatives like MAX6730UTVD3+T are preferred.

What package type and footprint does MAX6731UTVD3+T use?

MAX6731UTVD3+T uses the SOT23-6 package (JEDEC MO-178AC), measuring 1.6mm × 2.9mm × 0.95mm with 0.95mm pitch. Land pattern matches Maxim's outline 21-0058 / 90-0175. The '+T' suffix confirms RoHS-compliant, lead(Pb)-free construction - verified via Maxim's top-mark database and packaging documentation.