Analog Devices Inc./Maxim Integrated MAX6456UT23S+T

Overview

MAX6456UT23S+T from Maxim Integrated is a dual-voltage microprocessor supervisor IC with separate active-low open-drain VCC reset and manual reset outputs, 2.313V factory-set VCC threshold, 0.63V adjustable RSTIN threshold, 140ms minimum reset timeout, and 3.36s extended MR setup period for soft/hard reset combination. It operates from 1.0V to 5.5V supply and supports brownout detection in consumer electronics power management.

For engineers reviewing the MAX6456UT23S+T datasheet, MAX6456UT23S+T pinout, MAX6456UT23S+T application, or MAX6456UT23S+T equivalent, this device enables interrupt-before-reset functionality in set-top boxes, DVD players, and industrial equipment where controlled system recovery and voltage monitoring down to 0.63V are required.

Technical Context

The MAX6456UT23S+T implements a dual-comparator architecture: one precision bandgap reference comparator monitors VCC against a fixed 2.313V threshold, while a second high-impedance comparator monitors RSTIN against a fixed 0.63V internal reference-enabling external resistor-divider configuration for secondary voltage supervision. Its MR input controls both MROUT and RESET outputs via time-based logic.

When MR is held low for ≥3.36s (typ), RESET asserts alongside MROUT; shorter pulses trigger only MROUT. Both outputs feature 140ms minimum timeout after MR deassertion or voltage recovery, with guaranteed valid reset assertion down to VCC = 1.0V and immunity to transients ≤20µs at 100mV overdrive.

Key Specifications

Pinout & Package

Package: SOT23-6, surface-mount, lead(Pb)-free, -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6455UT23S+T, the MAX6456UT23S+T provides open-drain flexibility for multi-supply reset coordination; compared with TPS3808G33DBVR, it adds adjustable secondary rail supervision and programmable soft/hard reset behavior-critical for complex embedded recovery sequences.

Availability

MAX6456UT23S+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, cable modems, industrial equipment, and medical devices requiring stable component supply and long-term lifecycle support.

Supply support for MAX6456UT23S+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, interface, sensing, and reliability-critical applications.

The MAX6453–MAX6456 family was designed specifically for robust microprocessor supervision in consumer and industrial systems requiring dual-voltage monitoring, interrupt-before-reset capability, and extended temperature operation.

FAQ

What is the exact VCC reset threshold voltage for MAX6456UT23S+T?

The MAX6456UT23S+T has a factory-set VCC reset threshold of 2.313V, with ±0.075V tolerance over temperature. This value is fixed per the "23" suffix in the part number and is specified in Table 1 of the datasheet. The threshold remains stable across the full operating range (-40°C to +85°C) with a tempco of 60ppm/°C, ensuring consistent brownout detection in varying thermal environments. The MAX6456UT23S+T uses this precise threshold to monitor 2.5V or 3.3V system rails without external calibration.

How does the MR input control both RESET and MROUT in MAX6456UT23S+T?

In the MAX6456UT23S+T, the MR input controls both outputs via time-based logic: pulling MR low immediately asserts MROUT, while RESET asserts only if MR remains low for ≥3.36s (typical extended setup period). After MR transitions high, both outputs remain low for ≥140ms before deasserting. This dual-behavior enables a single pushbutton to deliver either an interrupt (short press) or full reboot (long press), a feature absent in MAX6453/MAX6454 variants. The MAX6456UT23S+T implements this using internal timing circuitry synchronized to VCC.

Can MAX6456UT23S+T monitor a 1.2V supply rail, and how is it configured?

Yes, the MAX6456UT23S+T can monitor a 1.2V rail using its RSTIN pin, which references a fixed 0.63V internal threshold. To configure, connect RSTIN to the center node of a resistor divider between the 1.2V rail and ground. Using the formula VMON_TH = 0.63 × (R1 + R2)/R2, select R2 = 250kΩ and calculate R1 ≈ 226kΩ for 1.2V trip point. This method allows precise secondary rail supervision without additional ICs. The MAX6456UT23S+T's high-impedance RSTIN input draws only ±25nA, minimizing divider current.

What is the minimum VCC voltage at which MAX6456UT23S+T guarantees valid RESET assertion?

The MAX6456UT23S+T guarantees valid RESET assertion down to VCC = 1.0V, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.0V, output drive strength degrades, but above this threshold, the open-drain RESET output maintains proper logic state and sink capability (≤0.3V at 50µA). This specification ensures reliable microprocessor reset initiation even during severe brownout events before complete power collapse. The MAX6456UT23S+T achieves this via BiCMOS process optimization and internal voltage regulation.

Is MAX6456UT23S+T compatible with 5V-tolerant microprocessor reset inputs?

Yes, the MAX6456UT23S+T's open-drain RESET output is compatible with 5V-tolerant inputs because its output can be pulled up to any voltage from 0V to 6V using an external resistor. When interfacing to a 5V µP, connect the pullup resistor to the 5V supply-not the MAX6456UT23S+T's VCC-enabling level translation. The MAX6456UT23S+T itself operates from 1.0V to 5.5V, so it can supervise lower-voltage rails while driving higher-voltage reset lines. This flexibility is documented in the Applications Information section.