Analog Devices Inc./Maxim Integrated MAX6358TZUT+T

Overview

MAX6358TZUT+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with open-drain active-low reset output, 3.08V VCC1 threshold, 2.32V VCC2 threshold, 46.4s watchdog startup timeout, and 2.9s normal watchdog timeout. It monitors two independent supply rails and asserts reset if either drops below its preset threshold, ensuring reliable power-up sequencing in multivoltage embedded systems.

For engineers reviewing the MAX6358TZUT+T datasheet, MAX6358TZUT+T pinout, MAX6358TZUT+T application, or MAX6358TZUT+T equivalent, key selection criteria include dual-supply monitoring capability, guaranteed RESET validity down to VCC1 = 1V or VCC2 = 1V, 20µA quiescent current, 100ms minimum reset pulse width, and integrated watchdog timer with dual-mode timeout architecture.

Technical Context

The MAX6358TZUT+T implements a dual-threshold comparator architecture that independently monitors VCC1 and VCC2 against factory-trimmed thresholds (3.08V and 2.32V respectively), asserting reset when either supply falls below its trip point. Its reset output remains valid as long as at least one supply exceeds +1.0V, enabling robust brownout detection in asymmetric power domains.

It integrates a dual-mode watchdog timer with a 46.4s startup timeout for system initialization and a 2.9s normal timeout for runtime supervision, triggered by WDI edge transitions. The open-drain RST output supports flexible pull-up configurations and interfaces directly with µP reset inputs requiring external biasing.

Key Specifications

Pinout & Package

MAX6358TZUT+T is housed in a 6-pin SOT23 package with 0.95mm pitch, RoHS-compliant lead(Pb)-free construction, and thermal performance rated for 695mW at +70°C (derating 8.7mW/°C above).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-voltage supervisory applications.

Compared with MAX6358TZUT+T, the MAX6358TZUT-T offers identical supervision performance but violates RoHS requirements, while the TPS3808G33DBVR reduces cost and complexity at the expense of dual-supply capability and watchdog supervision-making it unsuitable as a drop-in replacement.

Availability

MAX6358TZUT+T is available at Aetrix Electronics and suitable for industrial control systems, portable medical devices, automotive infotainment head units, and network edge routers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6358TZUT+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 is a semiconductor company specializing in analog and mixed-signal ICs for power management, sensing, and interface applications.

The MAX6351–MAX6360 product line delivers precision dual- and triple-voltage microprocessor supervisors for multirail embedded systems where reliability, low power, and guaranteed reset validity down to 1V are critical design requirements.

FAQ

What is the function of the WDI pin on the MAX6358TZUT+T?

The WDI (Watchdog Input) pin on the MAX6358TZUT+T accepts rising or falling edges to reset the internal watchdog timer. If no transition occurs within 2.9s during normal operation-or within 46.4s after power-up or reset-the device asserts the RST output. Leaving WDI unconnected disables the watchdog function entirely, and the MAX6358TZUT+T continues to operate as a dual-voltage supervisor without timeout supervision.

Does the MAX6358TZUT+T support operation with supply voltages below 2.0V?

Yes, the MAX6358TZUT+T guarantees functional reset assertion as long as either VCC1 or VCC2 remains above +1.0V, and its specified operating range starts at VCC1/VCC2 = +1.2V. The device's reset outputs remain valid down to 1V per rail, enabling use in ultra-low-voltage applications such as single-cell battery-powered systems where supply rails may dip near 1.8V or lower during discharge.

How does the MAX6358TZUT+T differ from the MAX6359TZUT+T?

The MAX6358TZUT+T provides an open-drain RST output, while the MAX6359TZUT+T features a push-pull RST output referenced to VCC1. Both share identical VCC1/VCC2 thresholds (3.08V/2.32V), watchdog timing (46.4s startup / 2.9s normal), and pinout. The choice depends on interface requirements: MAX6358TZUT+T needs an external pull-up resistor for reset signaling, whereas MAX6359TZUT+T drives reset actively high/low without external biasing.

What is the maximum transient duration the MAX6358TZUT+T can ignore on VCC1 or VCC2?

The MAX6358TZUT+T ignores negative-going transients on VCC1 or VCC2 up to durations defined by its reset threshold overdrive-e.g., a 100mV overdrive allows rejection of transients up to ~200µs, as shown in the "Maximum VCC Transient Duration vs. Reset Threshold Overdrive" graph in the datasheet. This immunity prevents false resets caused by switching noise or load-step-induced dips, provided the transient amplitude and duration fall within the specified envelope.

Can the MAX6358TZUT+T monitor three voltage rails?

No, the MAX6358TZUT+T monitors exactly two voltage rails (VCC1 and VCC2) and does not include the RSTIN input required for third-rail monitoring. That functionality is exclusive to the MAX6355/MAX6356/MAX6357 variants. Attempting to repurpose pins on the MAX6358TZUT+T for additional voltage monitoring is not supported and would violate absolute maximum ratings, as pin 5 is dedicated to WDI and lacks comparator input circuitry.