Analog Devices Inc./Maxim Integrated MAX6734KASVD3-T

Overview

MAX6734KASVD3-T from Maxim Integrated is a triple-voltage microprocessor supervisor IC with active-low open-drain reset and watchdog outputs, monitoring VCC1 (3.075V nominal), VCC2 (2.313V 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. Used in multivoltage embedded systems to ensure reliable power-on initialization and runtime fault detection.

For engineers reviewing the MAX6734KASVD3-T datasheet, MAX6734KASVD3-T pinout, MAX6734KASVD3-T application, or MAX6734KASVD3-T equivalent, key selection criteria include dual fixed-voltage thresholds (VCC1/VCC2), third adjustable voltage monitoring via RSTIN, manual reset input support, SOT23-8 package compatibility, and AEC-Q100 qualification status for automotive-grade reliability validation.

Technical Context

The MAX6734KASVD3-T implements independent voltage monitoring for three rails: primary supply VCC1 (3.075V threshold), secondary supply VCC2 (2.313V threshold), and externally scaled RSTIN (626mV internal reference). Reset assertion occurs when any monitored voltage falls below its threshold, with guaranteed validity down to VCC ≥ +0.8V.

Its watchdog timer operates in dual-mode: 35s (min) startup period after reset enables full system initialization, followed by 1.12s (min) normal timeout for rapid lockup detection. The active-low open-drain RST and WDO outputs require external pullups and support manual reset via MR input with 50kΩ internal pullup.

Key Specifications

Pinout & Package

MAX6734KASVD3-T is housed in an 8-pin SOT23 package (K8SN+1 outline), measuring 2.9mm × 1.6mm × 1.1mm, with 0.65mm pitch and exposed pad for thermal performance. Pin 1 is marked with a dot; device orientation follows JEDEC MO-178 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KASVD3-T, MAX6734KATGD3-T shifts VCC2 threshold downward for lower-voltage rails, while MAX6735KASVD3-T replaces open-drain outputs with push-pull drivers-both retain identical timing, manual reset, and RSTIN functionality but address distinct interface and supply architecture constraints.

Availability

MAX6734KASVD3-T is available at Aetrix Electronics and suitable for telecom power management, automotive infotainment, and industrial PLC controller applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6734KASVD3-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 high-reliability industrial, automotive, and communications systems, emphasizing low-power operation and robust environmental performance.

The MAX6730–MAX6735 family delivers integrated triple-voltage supervision with independent watchdog capability, targeting space-constrained embedded systems needing deterministic reset behavior and fail-safe runtime monitoring.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6734KASVD3-T?

The MAX6734KASVD3-T has a factory-set VCC1 reset threshold of 3.075V (nominal), with a guaranteed range of 3.000V to 3.150V at 25°C. This value corresponds to the 'T' suffix in the VCC1 threshold code and is optimized for monitoring +3.3V supply rails in embedded systems. The threshold exhibits ±20ppm/°C tempco and includes 0.5% hysteresis relative to typical value.

Does the MAX6734KASVD3-T support monitoring a third voltage rail, and how is it configured?

Yes, the MAX6734KASVD3-T supports third-rail monitoring via its RSTIN pin, which features a precise 626mV (611–642mV) internal reference. To monitor voltages above 626mV, connect a resistive divider between the target rail and RSTIN, selecting R1/R2 values so that V_{EXT_TH} = 626mV × (R1 + R2)/R2. The RSTIN input draws only ±25nA, enabling high-impedance scaling with minimal power impact.

What is the watchdog timeout behavior of the MAX6734KASVD3-T during system startup?

The MAX6734KASVD3-T implements a dual-mode watchdog timer: after any reset event (power-up, brownout, or manual reset), it enters a 35s minimum startup period before enforcing watchdog timeouts. During this phase, WDI transitions do not affect WDO state. Once the first valid WDI edge occurs-or after 35s expires-the timer switches to normal mode with a 1.12s minimum timeout, ensuring robust boot sequence completion before runtime lockup detection begins.

Is the MAX6734KASVD3-T qualified for automotive applications?

Yes, the MAX6734KASVD3-T is AEC-Q100 qualified for automotive use, meeting stress test requirements for Grade 3 (-40°C to +85°C) operation. Its design includes guaranteed reset validity down to VCC = +0.8V, immunity to short VCC transients, and stable performance across temperature extremes-making it suitable for infotainment, body control, and ADAS subsystems where functional safety and long-term reliability are critical.

How does the manual reset input (MR) interact with the watchdog timer in the MAX6734KASVD3-T?

Asserting the MR input low on the MAX6734KASVD3-T immediately clears the watchdog timer, deasserts WDO, and forces RST low for the full reset timeout period (210ms). This provides deterministic system recovery: pressing a reset button halts watchdog enforcement, initiates hardware reset, and restarts the watchdog's 35s startup delay upon release-ensuring clean reinitialization without residual timer state affecting subsequent operation.