Analog Devices Inc./Maxim Integrated MAX6734KASHD2+T

Overview

The MAX6734KASHD2+T from Maxim Integrated is a triple-voltage microprocessor supervisor IC with independent watchdog output, monitoring two fixed supply voltages (VCC1 = +2.925 V, VCC2 = +2.188 V) and one adjustable voltage via RSTIN (626 mV threshold), featuring open-drain RST and WDO outputs, 8.8 ms reset timeout, and manual reset input - used in telecom power sequencing and multivoltage embedded systems.

For engineers reviewing the MAX6734KASHD2+T datasheet, MAX6734KASHD2+T pinout, MAX6734KASHD2+T application, or MAX6734KASHD2+T equivalent, this page delivers verified electrical specs, SOT23-8 package details, watchdog timing behavior, reset threshold hysteresis, and real-world substitution guidance for industrial and telecom designs.

Technical Context

The MAX6734KASHD2+T implements dual fixed-threshold comparators (VTH1 = 2.925 V, VTH2 = 2.188 V) and a high-impedance adjustable comparator (VRSTIN = 626 mV) with 3 mV hysteresis, all referenced to an internal bandgap. Its reset logic asserts active-low RST when any monitored voltage falls below its threshold or MR is pulled low.

It integrates a dual-mode watchdog timer: 35 s minimum startup delay after reset, then 1.12 s minimum normal timeout; WDI edge detection clears the timer, and WDO asserts low on timeout or undervoltage lockout. Both RST and WDO are open-drain with 0.3 V VOL at 1.2 mA sink.

Key Specifications

Pinout & Package

MAX6734KASHD2+T is housed in an 8-pin SOT23-8 package (JEDEC MO-178AA), footprint-compatible with industry-standard 1.6 mm × 2.9 mm land pattern 90-0176, with 0.65 mm pitch and exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KASHD2+T, MAX6734KASGD2+T offers tighter VCC2 threshold for low-voltage cores but sacrifices compatibility with +2.5 V rails, while TPS3808G33DBVR reduces cost and current in single-rail applications but eliminates triple-monitoring and independent watchdog functionality required for complex SoCs.

Availability

MAX6734KASHD2+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, set-top boxes, and automotive infotainment systems requiring stable component supply, long-lifecycle support, and AEC-Q100-aligned reliability.

Supply support for MAX6734KASHD2+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, mixed-signal, and power management ICs for industrial, automotive, communications, and computing markets.

The MAX6730–MAX6735 family delivers integrated triple-voltage supervision with independent watchdog outputs for space-constrained, multirail embedded systems where reliability and deterministic reset timing are critical.

FAQ

What is the exact VCC1 and VCC2 reset threshold voltage for MAX6734KASHD2+T?

The MAX6734KASHD2+T has a VCC1 reset threshold of 2.925 V (nominal, falling) and a VCC2 reset threshold of 2.188 V (nominal, falling), per the 'SH' suffix in its part number and Table 1 of the datasheet. These values are factory-trimmed with ±1.5% tolerance over temperature and include 0.5% hysteresis to prevent chatter near threshold crossing.

Does MAX6734KASHD2+T support monitoring a third voltage, and how is it configured?

Yes, MAX6734KASHD2+T supports third-voltage monitoring via the RSTIN pin, which features a precise 626 mV internal reference. To monitor a higher voltage (e.g., +5 V), connect a resistive divider (R1/R2) between the rail and GND, with RSTIN tied to the divider midpoint. The formula is VEXT_TH = 626 mV × (R1 + R2)/R2, enabling accurate supervision of any rail ≥626 mV.

What is the watchdog timeout behavior of MAX6734KASHD2+T during system power-up?

Upon power-up or reset, MAX6734KASHD2+T enters a 35 s minimum initial watchdog mode to allow full system initialization. After this period expires-or after the first valid WDI edge-the watchdog switches to normal mode with a 1.12 s minimum timeout. This dual-mode architecture prevents false timeouts during boot while ensuring rapid hang detection during runtime.

Is MAX6734KASHD2+T compatible with bidirectional μP reset pins, and what interface precautions apply?

MAX6734KASHD2+T's open-drain RST output is compatible with bidirectional μP reset pins. However, to avoid contention with push-pull μP drivers, a 10 kΩ series resistor must be placed between RST and the μP's reset I/O port. This limits current during simultaneous drive and ensures clean reset assertion without logic conflict.

What package type and thermal characteristics does MAX6734KASHD2+T use?

MAX6734KASHD2+T uses an 8-pin SOT23-8 package (K8SN+1 outline, land pattern 90-0176) with θJA = 180°C/W and θJC = 60°C/W. It supports continuous power dissipation up to 444.4 mW at +70°C (derating 5.6 mW/°C above), making it suitable for compact PCB layouts with moderate airflow or heatsinking.