Analog Devices Inc./Maxim Integrated MAX6450UT26L+T

Overview

The MAX6450UT26L+T from Maxim Integrated is a dual-supply microprocessor reset supervisor IC featuring one fixed-threshold (2.625V) and one adjustable-threshold (0.63V reference) voltage monitor, two extended-setup manual reset inputs (MR1/MR2), open-drain active-low RESET output, and 6.72s minimum manual reset setup period - designed for reliable system initialization in set-top boxes and industrial equipment where nuisance resets must be eliminated.

For engineers reviewing the MAX6450UT26L+T datasheet, MAX6450UT26L+T pinout, MAX6450UT26L+T application, or MAX6450UT26L+T equivalent, key selection considerations include its dual-monitor architecture with RSTIN adjustability, 6.72s MR1/MR2 simultaneous hold requirement, guaranteed RESET assertion down to VCC = 1.0V, and SOT23-6 package compatibility with high-reliability embedded power sequencing.

Technical Context

The MAX6450UT26L+T implements a dual-comparator architecture: one precision internal bandgap comparator monitors VCC against a factory-set 2.625V threshold (±1.5% over -40°C to +85°C), while a second high-impedance comparator monitors external RSTIN using a 0.630V ±15mV reference to support user-defined thresholds via resistor divider. Both comparators feed into a shared reset timing engine.

Its manual reset logic requires simultaneous low assertion of MR1 and MR2 for ≥6.72s (tMR) to trigger a 140ms–280ms one-shot RESET pulse; transient immunity is enforced by 100ns glitch rejection on MR2 and 210ms debouncing on MR2 deassertion, ensuring robust front-panel switch interfacing without external RC networks.

Key Specifications

Pinout & Package

MAX6450UT26L+T is housed in a 6-pin SOT23 package (package code U6+1, outline 21-0058), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and exposed pad for thermal performance. Pin 1 is marked with dot; device orientation follows JEDEC MO-178.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6450UT26L+T, the MAX6450UT26K+T extends manual reset immunity at the cost of user responsiveness, while the MAX6449UT26L+T simplifies interface at the expense of dual-input safety features - both retain identical voltage monitoring accuracy and open-drain RESET behavior.

Availability

MAX6450UT26L+T is available at Aetrix Electronics and suitable for set-top boxes, industrial PLC modules, DVD players, and medical imaging equipment requiring stable component supply across extended temperature ranges and long-term production cycles.

Supply support for MAX6450UT26L+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 demanding industrial, automotive, and communications applications - emphasizing reliability, low power, and integration.

The MAX6443–MAX6452 family was engineered specifically for robust microprocessor supervision in noise-prone consumer and industrial environments, combining long manual reset setup, dual-supply monitoring, and guaranteed operation down to 1.0V VCC.

FAQ

What is the exact reset threshold voltage for VCC on the MAX6450UT26L+T?

The MAX6450UT26L+T has a factory-set VCC reset threshold of 2.625V, with ±1.5% tolerance over the full -40°C to +85°C temperature range. This value is fixed per the "26" suffix in the part number and is guaranteed by production testing - no adjustment is possible for the VCC monitor. The MAX6450UT26L+T uses this threshold to detect brownout on the primary supply rail.

How does the RSTIN pin function on the MAX6450UT26L+T?

The RSTIN pin on the MAX6450UT26L+T provides an adjustable voltage monitoring input referenced to an internal 0.630V ±15mV comparator threshold. It connects to the center node of an external resistor divider to set custom reset points for secondary supplies (e.g., 1.2V, 1.5V). The MAX6450UT26L+T does not monitor RSTIN alone - it asserts RESET if either VCC falls below 2.625V OR RSTIN falls below its programmed threshold.

What is the purpose of the dual manual reset inputs (MR1 and MR2) on the MAX6450UT26L+T?

The MAX6450UT26L+T requires both MR1 and MR2 to be held low simultaneously for ≥6.72 seconds (tMR) to initiate a reset pulse - this dual-input requirement prevents accidental resets from single-button presses. Neither input alone triggers RESET; both must meet the extended setup condition. This design is used in safety-critical or service-mode applications where deliberate operator action is mandatory - a key feature distinguishing the MAX6450UT26L+T from single-MR variants.

Does the MAX6450UT26L+T support open-drain or push-pull RESET output?

The MAX6450UT26L+T features an open-drain active-low RESET output, as indicated by the "T" suffix in the part number and confirmed in the Ordering Information table. It requires an external pullup resistor (minimum 20kΩ to VCC or another logic supply) and can interface safely with I/O voltages up to 6V. The MAX6450UT26L+T does not offer push-pull output - that variant is designated with "+" instead of "T" (e.g., MAX6450UT26L+).

What package type and dimensions does the MAX6450UT26L+T use?

The MAX6450UT26L+T is supplied in a 6-pin SOT23 package (package code U6+1, JEDEC MO-178 outline), measuring 2.9mm × 1.6mm with 0.95mm lead pitch. It includes an exposed thermal pad (non-electrical) and is RoHS-compliant ("+T" denotes lead-free). The pin 1 dot is located at the top-left corner when viewing the top mark side; the MAX6450UT26L+T pinout matches the standard SOT23-6 configuration shown in the Functional Diagram.