Analog Devices Inc./Maxim Integrated MAX6734KAZGD3+

Overview

MAX6734KAZGD3+ from Maxim Integrated is a triple-voltage microprocessor supervisor IC with active-low open-drain reset and watchdog outputs, monitoring VCC1 (2.25V nominal), VCC2 (2.313V nominal), and an adjustable RSTIN input down to 0.63V. It features a 140ms–280ms reset timeout, 35s initial watchdog startup delay, and 1.12s normal watchdog timeout, designed for reliable power-on sequencing and lockup recovery in multivoltage embedded systems.

For engineers reviewing the MAX6734KAZGD3+ datasheet, MAX6734KAZGD3+ pinout, MAX6734KAZGD3+ application, or MAX6734KAZGD3+ equivalent, this page delivers verified electrical thresholds, SOT23-8 package mapping, manual reset timing, watchdog behavior under brownout, and real-world substitution guidance for industrial and telecom power management designs.

Technical Context

The MAX6734KAZGD3+ integrates three independent voltage monitors: a factory-set 2.25V/2.313V dual-threshold comparator for VCC1/VCC2 and a high-impedance 626mV reference-based RSTIN input for third-rail monitoring. Its dual-mode watchdog timer provides a 35s minimum startup delay after reset and transitions to a 1.12s minimum timeout upon first WDI edge detection.

Reset assertion is guaranteed valid down to VCC1 or VCC2 = +0.8V, with immunity to short VCC transients via built-in glitch rejection. The open-drain RST and WDO outputs require external pullups and support bidirectional μP reset pins when used with series termination.

Key Specifications

Pinout & Package

MAX6734KAZGD3+ is housed in an 8-pin SOT23 package (K8SN+1 outline), measuring 2.9mm × 1.6mm × 1.1mm, with lead(Pb)-free RoHS-compliant construction and JEDEC-standard thermal characteristics (θJA = 180°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KAZGD3+, MAX6734KALTD3+ offers different factory-set thresholds but identical triple-monitor architecture and SOT23-8 footprint, while TPS3808G33DBVR reduces functionality to single-rail supervision with no RSTIN flexibility-making it a partial substitute only in simplified power domains.

Availability

MAX6734KAZGD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, network switching equipment, and medical imaging devices requiring stable component supply across extended temperature ranges.

Supply support for MAX6734KAZGD3+ 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 management, sensing, and connectivity in demanding industrial and communications applications.

The MAX6730–MAX6735 family was engineered specifically for multivoltage microprocessor systems requiring coordinated reset assertion, manual intervention, and robust watchdog supervision across wide temperature ranges.

FAQ

What is the exact reset threshold voltage for VCC1 on MAX6734KAZGD3+?

The MAX6734KAZGD3+ has a factory-set VCC1 reset threshold of 2.25V (minimum), 2.313V (typical), and 2.375V (maximum), corresponding to the 'Z' suffix in its part number. This threshold is guaranteed over the full -40°C to +85°C operating range and exhibits ±20ppm/°C tempco. The device asserts RST low when VCC1 falls below this level and holds reset for the full 140ms–280ms D3 timeout period.

Does MAX6734KAZGD3+ support monitoring a third voltage rail, and how is it configured?

Yes, MAX6734KAZGD3+ supports third-rail monitoring via its RSTIN pin, which features a precise 626mV internal reference. To monitor voltages above 626mV, connect a resistive voltage divider between the target rail and GND, with the midpoint fed to RSTIN. The divider ratio sets the effective threshold: V_{EXT_TH} = 626mV × (R1 + R2)/R2. RSTIN's ±25nA input current enables high-impedance dividers that minimize system power draw.

What is the watchdog behavior of MAX6734KAZGD3+ during power-up?

Upon power-up or reset, MAX6734KAZGD3+ enters a 35s minimum watchdog startup delay before activating normal supervision. During this period, WDO remains deasserted regardless of WDI state, allowing full system initialization. After the first valid WDI edge, the watchdog transitions to its 1.12s minimum timeout mode. If no edge occurs within 35s, WDO asserts low, signaling initialization failure.

Can MAX6734KAZGD3+ operate reliably during brownout conditions?

Yes, MAX6734KAZGD3+ guarantees functional reset assertion down to VCC1 or VCC2 = +0.8V, maintaining valid RST output even as supplies collapse. Its open-drain RST output remains controllable in this region, and the internal comparators retain accuracy. For applications requiring reset validity down to 0V, a 100kΩ pulldown resistor from RST to GND is recommended-but note this conflicts with open-drain operation and is not needed for standard use cases.

What package type and footprint does MAX6734KAZGD3+ use?

MAX6734KAZGD3+ uses an 8-pin SOT23 package (K8SN+1 outline), with dimensions of 2.9mm × 1.6mm × 1.1mm and RoHS-compliant lead(Pb)-free terminations. Its land pattern matches JEDEC MO-178AA standards, and thermal resistance is specified at θJA = 180°C/W and θJC = 60°C/W. This compact footprint supports high-density PCB layouts in space-constrained telecom and industrial modules.