Analog Devices Inc./Maxim Integrated MAX6456UT29S

Overview

MAX6456UT29S from Maxim Integrated is a dual-voltage microprocessor supervisor IC with separate active-low open-drain VCC reset and manual reset outputs, factory-set 2.925V VCC reset threshold, adjustable RSTIN monitoring down to 0.63V, 140ms minimum reset timeout, and extended 3.36s manual reset setup period for soft/hard reset combination control in embedded power management systems.

For engineers reviewing the MAX6456UT29S datasheet, MAX6456UT29S pinout, MAX6456UT29S application, or MAX6456UT29S equivalent, this device supports interrupt-before-reset sequencing, brownout immunity, low-power (6µA typical) operation, and robust reset assertion down to VCC = 1.0V - critical for reliable boot-up in consumer electronics and industrial equipment.

Technical Context

The MAX6456UT29S implements a dual-comparator architecture: one precision bandgap-based comparator monitors VCC against a fixed 2.925V threshold (±1.5% over temperature), while a second high-impedance comparator monitors RSTIN against a fixed 0.63V reference, enabling external resistor-divider configuration for secondary voltage supervision. Both comparators feed independent reset logic paths.

Its MR input controls both MROUT and RESET outputs: short MR pulses (<3.36s) assert only MROUT for nonmaskable interrupt signaling; sustained MR assertion (≥3.36s) triggers full system reboot via RESET. The 140ms minimum timeout ensures stable deassertion after voltage recovery, and open-drain outputs support flexible voltage-level interfacing up to 6V.

Key Specifications

Pinout & Package

Package: SOT23-6, surface-mount, lead(Pb)-free compatible (order as MAX6456UT29S+T), -40°C to +85°C operating range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6456UT29S, MAX6455UT29S offers identical supervision logic but eliminates external pullup requirements at the cost of wiring flexibility, while TPS3808G33DBVR reduces feature set to basic reset generation - making MAX6456UT29S uniquely suited for systems requiring coordinated soft/hard reset and multi-rail monitoring.

Availability

MAX6456UT29S is available at Aetrix Electronics and suitable for set-top boxes, DVD players, and cable modems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6456UT29S 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 management, sensing, and interface applications.

The MAX6453–MAX6456 family delivers dual-output µP supervisors optimized for consumer and industrial systems needing coordinated interrupt-and-reboot functionality with minimal external components.

FAQ

What is the exact VCC reset threshold voltage for MAX6456UT29S?

The MAX6456UT29S has a factory-trimmed VCC reset threshold of 2.925V, with ±1.5% tolerance over the full -40°C to +85°C temperature range. This value is confirmed in Table 1 of the datasheet and corresponds to the "29" suffix in the part number. The threshold is internally generated and does not require calibration or external components.

Does MAX6456UT29S support monitoring a secondary voltage below 1.0V?

Yes, MAX6456UT29S supports monitoring secondary voltages as low as 0.63V directly at the RSTIN pin, and with an external resistor divider, it can supervise voltages down to 0.63V - including sub-1.0V rails like 0.9V or 0.8V core supplies. The RSTIN input has 25nA max leakage and 0.63V ±15mV reference accuracy, enabling precise low-voltage detection without additional ICs.

How does the manual reset function differ between MAX6456UT29S and MAX6454UT29S?

Unlike MAX6454UT29S (which drives only MROUT on MR assertion), MAX6456UT29S uses MR to control both MROUT and RESET outputs. A short MR pulse asserts only MROUT for interrupt signaling; holding MR low for ≥3.36s additionally asserts RESET for full system reboot. This dual-mode behavior is enabled by internal timing logic unique to the MAX6455/MAX6456 variants.

What is the minimum VCC voltage at which MAX6456UT29S guarantees valid RESET output?

MAX6456UT29S guarantees correct RESET output logic state down to VCC = 1.0V, as specified in the Electrical Characteristics table. Below 1.0V, output sinking capability degrades, but for most microprocessors that cease operation above 1.0V, this ensures reset integrity across the entire functional supply range without external circuitry.

Can MAX6456UT29S be used with a 5V pullup on its open-drain RESET output while VCC is 3.3V?

Yes, MAX6456UT29S open-drain RESET output is rated for 6V maximum voltage, allowing direct connection to a 5V pullup even when VCC = 3.3V. This enables level-shifting to higher-voltage logic domains. The datasheet confirms safe operation with pullup to any voltage from 0V to 6V, provided the sink current stays within spec (≤3.2mA at VCC ≥ 4.25V).