Analog Devices Inc./Maxim Integrated MAX6734KASYD3+TG24

Overview

MAX6734KASYD3+TG24 from Maxim Integrated is a triple-voltage microprocessor supervisor IC with active-low open-drain reset and watchdog outputs, monitoring VCC1 (+2.925V nominal), VCC2 (+2.188V nominal), and an adjustable RSTIN input (626mV threshold). It features 210ms minimum reset timeout, 35s initial watchdog startup delay, and 1.12s normal watchdog timeout. Designed for multivoltage embedded systems requiring reliable power-on reset and lockup recovery.

For engineers reviewing the MAX6734KASYD3+TG24 datasheet, MAX6734KASYD3+TG24 pinout, MAX6734KASYD3+TG24 application, or MAX6734KASYD3+TG24 equivalent, key selection criteria include dual fixed-voltage thresholds (2.925V/2.188V), adjustable third-voltage monitoring capability, SOT23-8 package compatibility, and AEC-Q100-qualified variants for automotive use.

Technical Context

The MAX6734KASYD3+TG24 implements independent voltage monitoring for three rails: primary supply (VCC1), secondary supply (VCC2), and an externally scaled third rail via RSTIN. Its internal 626mV reference enables precise undervoltage detection down to +0.63V using external resistor dividers.

It integrates a dual-mode watchdog timer-35s min startup period after reset and 1.12s min normal mode timeout-with independent WDO output. Reset assertion requires all monitored voltages to exceed their thresholds before the 210ms timeout expires, and manual reset (MR) forces immediate assertion with 200ns propagation delay.

Key Specifications

Pinout & Package

MAX6734KASYD3+TG24 is housed in an 8-pin SOT23-8 package (JEDEC MO-178AA), measuring 2.9mm × 1.6mm × 1.1mm, with lead(Pb)-free RoHS-compliant plating and thermal resistance θJA = 180°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KASYD3+TG24, the AEC-Q100 variant adds automotive qualification without altering functionality, while TPS3808G33DBVR sacrifices triple-monitoring capability for lower cost and simpler integration in single-rail designs.

Availability

MAX6734KASYD3+TG24 is available at Aetrix Electronics and suitable for industrial control systems, automotive infotainment modules, and network infrastructure equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6734KASYD3+TG24 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, automotive, and communications applications, emphasizing reliability, low power, and integration.

The MAX6730–MAX6735 family delivers compact, triple-rail microprocessor supervision with independent watchdog outputs-targeting space-constrained embedded systems needing robust power-up sequencing and runtime fault detection.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6734KASYD3+TG24?

The MAX6734KASYD3+TG24 has a factory-set VCC1 reset threshold of +2.925V (typical), with guaranteed range of +2.850V to +3.000V at 25°C. This corresponds to the "S" suffix in the VCC1 threshold coding per Maxim's Suffix Guide, and is designed for reliable monitoring of standard 3.0V system rails.

Does the MAX6734KASYD3+TG24 support monitoring a third voltage rail, and how is it configured?

Yes, the MAX6734KASYD3+TG24 supports third-rail monitoring via its RSTIN pin, which features a precise +626mV internal reference. To monitor a higher voltage (e.g., 5V or 12V), connect a resistive voltage divider between the rail and GND, feeding the midpoint to RSTIN. The divider ratio must scale the rail voltage to ≤626mV at the RSTIN node.

What is the function of the MR pin on the MAX6734KASYD3+TG24, and what are its electrical requirements?

The MR (Manual Reset) pin on the MAX6734KASYD3+TG24 is an active-low input that forces immediate reset assertion regardless of supply conditions. It features an internal 50kΩ pullup to VCC1, accepts TTL/CMOS logic levels, requires ≥1µs pulse width, and exhibits 100ns glitch rejection. Leaving MR unconnected defaults to inactive (high) state.

How does the watchdog timer operate on the MAX6734KASYD3+TG24, and what are its timing modes?

The MAX6734KASYD3+TG24 watchdog operates in two modes: a 35s (min) startup delay after each reset event-allowing full system initialization-and a 1.12s (min) normal timeout during steady-state operation. A rising or falling edge on WDI resets the timer; failure to provide such an edge within the active timeout causes WDO to assert low.

Is the MAX6734KASYD3+TG24 pin-compatible with other devices in the MAX6730–MAX6735 family?

Yes, the MAX6734KASYD3+TG24 shares the same SOT23-8 pinout and footprint with all MAX6734 and MAX6735 variants, including MAX6734KATGD3/V+T and MAX6735KASYD3+TG24. However, it is not pin-compatible with the 6-pin MAX6730–MAX6733 series due to differing pin count and RSTIN/WDI placement.