Analog Devices Inc./Maxim Integrated MAX6455UT46S+T

Overview

MAX6455UT46S+T from Maxim Integrated is a dual-voltage microprocessor supervisor IC with separate active-low push-pull RESET and MROUT outputs, factory-set 4.625V VCC reset threshold, adjustable RSTIN input (0.63V reference), and 3.36s extended manual reset setup period. It supports soft-system interrupt (MROUT) and hard-system reboot (RESET) from a single MR input in consumer and industrial embedded systems.

For engineers reviewing the MAX6455UT46S+T datasheet, MAX6455UT46S+T pinout, MAX6455UT46S+T application, or MAX6455UT46S+T equivalent, this device enables reliable power-on reset, brownout detection, and user-initiated interrupt-before-reset functionality in space-constrained SOT23-6 designs requiring stable 140ms minimum timeout and operation down to VCC = 1.0V.

Technical Context

The MAX6455UT46S+T implements a dual-comparator architecture: one precision bandgap-based comparator monitors VCC against a fixed 4.625V threshold (±1.5% over -40°C to +85°C), while a high-impedance (±25nA) comparator monitors RSTIN against a 0.63V internal reference. Its MR input controls both outputs - short press (<3.36s) asserts only MROUT; long press (≥3.36s) asserts both MROUT and RESET.

RESET and MROUT are active-low push-pull outputs capable of sinking 1.2mA at VCC ≥ 2.55V (VOL ≤ 0.3V), with guaranteed valid logic states down to VCC = 1.0V. The device draws only 6µA typical supply current at 3.6V and features 60ppm/°C reset threshold tempco and 2.5mV RSTIN hysteresis for noise immunity.

Key Specifications

Pinout & Package

SOT23-6 package with 1.6mm × 2.9mm footprint, lead(Pb)-free, RoHS-compliant, rated for 696mW continuous power dissipation at +70°C (derates 8.7mW/°C above).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6455UT46S+T, the MAX6455UT46L+T extends manual reset setup time for enhanced user intent validation, while the MAX6456UT46S+T replaces push-pull outputs with open-drain for flexible voltage-domain interfacing - neither is pin-compatible without layout revision due to differing output drive architecture.

Availability

MAX6455UT46S+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, cable modems, industrial HMIs, and medical diagnostic devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6455UT46S+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 power, sensing, connectivity, and security applications, with emphasis on high-reliability industrial and consumer solutions.

The MAX6453–MAX6456 family delivers dual-output µP supervision with configurable reset timing and voltage thresholds, targeting cost-sensitive, space-constrained embedded systems needing robust power-monitoring and user-initiated recovery.

FAQ

What is the exact VCC reset threshold voltage for MAX6455UT46S+T?

The MAX6455UT46S+T has a factory-set VCC reset threshold of 4.625V, with guaranteed tolerance of ±1.5% over the full -40°C to +85°C operating range. This value is fixed by the "46" suffix per Table 1 and confirmed in the Electrical Characteristics table under VTH parameter with MIN/TYP/MAX values of 4.50V/4.63V/4.75V.

How does the manual reset input behave on MAX6455UT46S+T compared to MAX6453UT46S+T?

On the MAX6455UT46S+T, the MR input controls both MROUT and RESET outputs: short press (<3.36s) asserts only MROUT, while long press (≥3.36s) asserts both. In contrast, MAX6453UT46S+T's MR affects only MROUT - its RESET output responds solely to VCC/RSTIN voltage faults, not MR state.

Can MAX6455UT46S+T monitor a 1.8V supply using the RSTIN pin?

Yes. The MAX6455UT46S+T RSTIN pin uses a 0.63V internal reference, so a resistor divider (e.g., R1 = 187kΩ, R2 = 100kΩ) scales the 1.8V supply to ~0.63V at RSTIN. The formula VMON_TH = 0.63 × (R1 + R2)/R2 confirms this configuration yields a 1.79V threshold, matching design requirements.

What is the minimum VCC voltage at which MAX6455UT46S+T guarantees valid RESET output logic?

The MAX6455UT46S+T guarantees valid RESET output logic (low/high states) down to VCC = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.0V, RESET current-sinking capability degrades, and external pulldown may be needed for push-pull operation - but 1.0V is the documented lower limit for guaranteed functionality.

Does MAX6455UT46S+T support operation at 1.2V VCC?

No. The MAX6455UT46S+T has a minimum operating VCC of 1.0V, but its 4.625V factory-set reset threshold requires VCC ≥ 4.625V to avoid immediate assertion of RESET. Operating at 1.2V would force RESET permanently low, making it unsuitable for 1.2V system monitoring - use RSTIN with external divider instead for lower-voltage rails.