Analog Devices Inc./Maxim Integrated MAX6730UTTD3+T

Overview

MAX6730UTTD3+T from Maxim Integrated is a single-voltage microprocessor supervisor IC with active-low open-drain reset output, manual reset input, and independent watchdog timer. It monitors VCC1 with factory-set 4.625V threshold (suffix "TT"), provides 140–280ms reset timeout (D3), consumes 14µA typical supply current, and operates from -40°C to +85°C in SOT23-6 package - used for reliable power-on reset and lockup recovery in embedded microcontroller systems.

For engineers reviewing the MAX6730UTTD3+T datasheet, MAX6730UTTD3+T pinout, MAX6730UTTD3+T application, or MAX6730UTTD3+T equivalent, key selection criteria include its fixed 4.625V VCC1 reset threshold, 140–280ms timeout, open-drain RST output compatibility with bidirectional μP reset pins, and 54s watchdog startup delay enabling safe system initialization.

Technical Context

The MAX6730UTTD3+T integrates a precision voltage comparator for VCC1 monitoring with ±1.25% threshold accuracy over temperature, a digital reset timeout counter with six selectable periods (D3 = 140–280ms), and a dual-mode watchdog timer featuring 54s initial startup delay followed by 1.68s normal-mode timeout. Its internal 50kΩ MR pullup enables direct switch-to-ground connection without external components.

It uses BiCMOS process technology to achieve low 14µA supply current at 3.6V while guaranteeing valid reset assertion down to VCC1 = +0.8V. The open-drain RST output requires an external pullup resistor and is compatible with TTL/CMOS logic levels, supporting interfacing with bidirectional μP reset I/O ports via a 10kΩ series resistor to prevent contention.

Key Specifications

Pinout & Package

MAX6730UTTD3+T is housed in a 6-pin SOT23-6 package (outline 21-0058) with 0.95mm pitch, 2.9mm × 1.6mm footprint, and JEDEC-standard thermal characteristics (θJA = 230°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6730UTTD3+T, MAX6731UTTD3+T offers push-pull drive convenience but sacrifices open-drain flexibility, while TPS3808G33DBVR reduces supply current by 82% but removes manual reset and limits voltage monitoring to 3.3V - making MAX6730UTTD3+T optimal for 4.63V systems requiring field-serviceable reset capability.

Availability

MAX6730UTTD3+T is available at Aetrix Electronics and suitable for industrial control systems, network infrastructure equipment, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6730UTTD3+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, communications, and computing applications.

The MAX6730–MAX6735 family delivers single/dual/triple-voltage supervision with integrated watchdog timers for microprocessor-based systems requiring high reliability, low power, and minimal external components.

FAQ

What is the exact reset threshold voltage for MAX6730UTTD3+T?

The MAX6730UTTD3+T has a factory-set VCC1 reset threshold of 4.625V (TT suffix), with guaranteed min/max values of 4.500V and 4.750V across -40°C to +85°C. This threshold applies exclusively to the primary supply (VCC1) input; the device does not monitor VCC2 or RSTIN, as those features are reserved for higher-variant parts like MAX6732–MAX6735.

Does MAX6730UTTD3+T support manual reset functionality?

Yes, MAX6730UTTD3+T includes an active-low manual reset input (MR) with an internal 50kΩ pullup resistor to VCC1. Driving MR low forces RST assertion for the full reset timeout period (140–280ms), and the pin accepts TTL/CMOS logic levels. Leaving MR unconnected defaults it to high via the internal pullup, making external components unnecessary for basic operation.

What is the watchdog timeout behavior of MAX6730UTTD3+T?

MAX6730UTTD3+T implements a dual-mode watchdog timer: a 54s minimum startup delay after any reset event (power-up, brownout, or MR assertion), followed by a 1.68s minimum normal-mode timeout. The watchdog clears on any WDI edge (rising or falling) and asserts WDO low if no transition occurs within the active timeout window - ensuring robust detection of software lockups post-initialization.

Can MAX6730UTTD3+T be used with bidirectional microprocessor reset pins?

Yes, MAX6730UTTD3+T's open-drain RST output is specifically suited for bidirectional μP reset I/O ports. To prevent logic contention, connect a 10kΩ series resistor between RST and the μP pin. This configuration allows the μP to drive the line high during normal operation while permitting MAX6730UTTD3+T to assert low during fault conditions - a key advantage over push-pull alternatives.

What package and RoHS status does MAX6730UTTD3+T have?

MAX6730UTTD3+T is supplied in a lead(Pb)-free, RoHS-compliant 6-pin SOT23-6 package (package code U6+1, outline 21-0058). The "+T" suffix explicitly denotes lead-free termination. Its compact 2.9mm × 1.6mm footprint and 0.95mm pin pitch support high-density PCB layouts while meeting modern environmental compliance requirements.