Analog Devices Inc./Maxim Integrated MAX6358LRUT+T

Overview

MAX6358LRUT+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with open-drain active-low reset output, 4.63V/2.63V factory-set VCC1/VCC2 thresholds, integrated watchdog timer (46.4s startup / 2.9s normal timeout), and guaranteed RESET validity down to VCC1 ≥ 1.0V or VCC2 ≥ 1.0V. It monitors two independent power rails in multivoltage embedded systems requiring reliable power-on reset and processor activity supervision.

For engineers reviewing the MAX6358LRUT+T datasheet, MAX6358LRUT+T pinout, MAX6358LRUT+T application, or MAX6358LRUT+T equivalent, key selection criteria include dual-supply threshold accuracy (±1.5% over -40°C to +85°C), 20µA quiescent current, 100ms minimum reset pulse width, and watchdog input timing compatibility with boot-critical firmware sequences.

Technical Context

The MAX6358LRUT+T implements a dual-threshold comparator architecture monitoring VCC1 and VCC2 independently; reset asserts if either supply falls below its specified trip point (4.63V for VCC1, 2.63V for VCC2). Its watchdog timer features two distinct timeout modes: a 46.4s startup period for system initialization and a 2.9s normal mode for runtime fault detection.

It uses an open-drain RST output referenced to VCC1, requiring external pull-up, and includes a debounced TTL/CMOS-compatible manual-reset input (MR) with 1µs minimum pulse width. The device guarantees functional operation with either VCC1 or VCC2 ≥ 1.0V, enabling robust reset assertion during brownout conditions.

Key Specifications

Pinout & Package

MAX6358LRUT+T is housed in a 6-pin SOT23 package (U6-1 outline, 90-0175 land pattern), RoHS-compliant with lead(Pb)-free termination (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6358LRUT+T, the MAX6358LRUT-T offers identical performance in a non-RoHS package, while the MAX6359LRUT+T replaces the open-drain RST with a push-pull output-enabling simpler interface at the cost of losing wired-OR capability.

Availability

MAX6358LRUT+T is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical diagnostics, automotive infotainment gateways, and network edge routers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6358LRUT+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 high-performance analog and mixed-signal ICs for industrial, communications, and consumer applications, with emphasis on reliability and integration.

The MAX6351–MAX6360 family delivers dual- and triple-voltage µP supervisors optimized for multirail embedded systems where precision threshold monitoring, low power, and watchdog supervision are critical.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6358LRUT+T?

The MAX6358LRUT+T has factory-set thresholds of 4.63V for VCC1 and 2.63V for VCC2, each with ±1.5% tolerance over the full -40°C to +85°C operating range. These values are laser-trimmed during production and do not require external calibration. The "LR" suffix in MAX6358LRUT+T directly encodes these thresholds per Maxim's ordering convention.

Does the MAX6358LRUT+T provide a push-pull or open-drain reset output?

The MAX6358LRUT+T provides an active-low open-drain RST output (Pin 1), requiring an external pull-up resistor to the appropriate logic rail (typically VCC1). This configuration supports wired-OR reset buses and level translation. Unlike the MAX6359LRUT+T, it does not drive high actively-its RST pin can only pull low or float.

How does the watchdog timer on the MAX6358LRUT+T operate during system startup?

The MAX6358LRUT+T watchdog timer initiates a 46.4s startup timeout period after any reset event (power-on, MR assertion, or watchdog timeout). During this interval, the system may complete bootloading without needing WDI toggles. Once the startup period expires-or upon the first valid WDI edge-the timer switches to 2.9s normal timeout mode for continuous runtime supervision.

Can the MAX6358LRUT+T maintain a valid reset signal if one supply drops below 1.0V?

No-the MAX6358LRUT+T guarantees RESET validity only as long as *either* VCC1 ≥ 1.0V *or* VCC2 ≥ 1.0V. If both supplies fall below 1.0V simultaneously, the internal circuitry cannot sustain correct RST state. However, the device continues asserting RST low until that point, providing maximum brownout coverage before loss of functionality.

What is the minimum pulse width required on the MR input to trigger a reset on the MAX6358LRUT+T?

The MR input of the MAX6358LRUT+T requires a minimum low pulse width of 1µs to reliably assert reset. This short requirement enables compatibility with fast digital outputs and debounced mechanical switches. The internal MR circuit includes filtering to reject glitches shorter than 100ns, enhancing noise immunity in electrically noisy environments.