Analog Devices Inc./Maxim Integrated MAX6734KAYDD3+T

Overview

MAX6734KAYDD3+T from Maxim Integrated is a triple-voltage microprocessor supervisor IC with independent watchdog timer, monitoring VCC1 (4.375V nominal), VCC2 (2.625V nominal), and an adjustable RSTIN input (626mV threshold). It features open-drain RST and WDO outputs, 140ms–280ms reset timeout (D3 option), and operates across –40°C to +85°C. It is used in multivoltage embedded systems requiring reliable power-on reset and system lockup protection.

For engineers reviewing the MAX6734KAYDD3+T datasheet, MAX6734KAYDD3+T pinout, MAX6734KAYDD3+T application, or MAX6734KAYDD3+T equivalent, this page delivers verified electrical parameters, SOT23-8 package mapping, manual reset timing, watchdog startup/normal modes, and real-world use cases in telecom, industrial, and portable equipment.

Technical Context

The MAX6734KAYDD3+T integrates three independent voltage monitors: a factory-set VCC1 threshold (MR suffix = 4.375V), VCC2 threshold (R suffix = 2.625V), and a high-impedance RSTIN comparator referenced to 626mV. Its dual-mode watchdog provides a 35s minimum startup delay after reset and a 1.12s minimum normal timeout, both triggered by WDI edge transitions.

Reset assertion is guaranteed down to VCC1 or VCC2 = +0.8V, with 45µs VCC-to-RST delay and 22µs RSTIN-to-RST delay. The device uses BiCMOS process, draws 14µA typical supply current at +3.6V, and supports manual reset via MR with 50kΩ internal pullup and 1µs minimum pulse width.

Key Specifications

Pinout & Package

MAX6734KAYDD3+T is housed in an 8-pin SOT23-8 package (K8SN+1 outline), measuring 2.9mm × 1.6mm × 1.1mm, with 0.65mm pitch and RoHS-compliant lead-free finish (+T).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KALTD3+T and MAX6735KAYDD3+T, the MAX6734KAYDD3+T uniquely balances +4.375V/+2.625V fixed monitoring with adjustable third-rail support and open-drain flexibility-making it optimal for industrial and telecom systems requiring robust, noise-immune reset coordination across mixed-voltage domains.

Availability

MAX6734KAYDD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and portable medical equipment requiring stable component supply, long-lifecycle assurance, and RoHS-compliant packaging.

Supply support for MAX6734KAYDD3+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 power, sensing, and interface applications, with emphasis on reliability and integration.

The MAX6730–MAX6735 family targets embedded systems needing compact, low-power, multi-rail supervision with watchdog safety-specifically engineered for telecom, computing, and industrial equipment where deterministic reset behavior is critical.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6734KAYDD3+T?

The MAX6734KAYDD3+T has a VCC1 reset threshold of 4.375V (MR suffix) and a VCC2 reset threshold of 2.625V (R suffix), both specified at typical conditions with ±1.5% tolerance over temperature. These values are factory-trimmed and guaranteed per the Electrical Characteristics table in the official datasheet.

Does the MAX6734KAYDD3+T support monitoring a third voltage, and how is it configured?

Yes, the MAX6734KAYDD3+T supports third-voltage monitoring via the RSTIN pin, which has a fixed 626mV internal reference. To monitor voltages above 0.63V, connect a resistive divider between the target rail and GND, with the midpoint fed to RSTIN. The divider ratio must scale the rail voltage to exactly 626mV at trip point.

What are the watchdog timeout periods for the MAX6734KAYDD3+T, and how do they operate?

The MAX6734KAYDD3+T features two watchdog timeout modes: a 35s minimum startup delay after reset (to allow full system initialization), followed by a 1.12s minimum normal timeout during runtime. Both are triggered by missing edges on WDI, and the timer clears on any valid rising or falling transition.

Is the MAX6734KAYDD3+T compatible with manual reset pushbuttons, and what is the MR input behavior?

Yes, the MAX6734KAYDD3+T includes a dedicated MR pin with an internal 50kΩ pullup to VCC1. A momentary switch from MR to GND asserts reset; the device holds RST low for the full D3 timeout (140–280ms) after MR releases. No external debounce is required due to built-in 100ns glitch rejection.

What package type and footprint does the MAX6734KAYDD3+T use, and are thermal characteristics documented?

The MAX6734KAYDD3+T uses an 8-pin SOT23-8 package (K8SN+1 outline) with 0.65mm pitch. Thermal data shows θJA = 180°C/W and θJC = 60°C/W on a four-layer JEDEC board. Maximum power dissipation is 444.4mW at +70°C, derating 5.6mW/°C above that temperature.