Analog Devices Inc./Maxim Integrated MAX6456UT29L+T

Overview

MAX6456UT29L+T 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, 6.72s extended MR setup period, 140ms min reset timeout, and adjustable RSTIN input supporting down to 0.63V - used for soft/hard system reset coordination in embedded power management.

For engineers reviewing the MAX6456UT29L+T datasheet, MAX6456UT29L+T pinout, MAX6456UT29L+T application, or MAX6456UT29L+T equivalent, key selection criteria include its dual-output reset architecture, MR-controlled combined interrupt/reset behavior, SOT23-6 open-drain interface compatibility, guaranteed reset validity down to VCC = 1.0V, and immunity to sub-20µs VCC transients.

Technical Context

The MAX6456UT29L+T implements a dual-comparator supervisory architecture: one precision bandgap-based comparator monitors VCC against a fixed 2.925V threshold, while a high-impedance RSTIN input enables external resistor-divider–based monitoring of secondary voltages down to 0.63V. Its MR input controls both MROUT and RESET outputs via an extended setup timeout (6.72s typical), enabling pushbutton-triggered NMI interrupt followed by full reboot.

This device uses BiCMOS process technology, operates across -40°C to +85°C, and guarantees valid reset assertion even as VCC decays to 1.0V. The open-drain outputs require external pullups and support level-shifting up to 6V, with leakage <1µA when deasserted and VOL ≤0.4V at ISINK = 3.2mA.

Key Specifications

Pinout & Package

SOT23-6 package with exposed pad (RoHS-compliant lead-free +T variant); 2.9mm × 1.6mm × 1.1mm body, 0.95mm pitch, GND-connected thermal pad recommended for thermal stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6455UT29L+T, the MAX6456UT29L+T offers open-drain flexibility for bus sharing and voltage translation; compared with TPS3808G33DBVR, it delivers critical dual-output architecture and adjustable secondary monitoring essential for complex embedded recovery sequences.

Availability

MAX6456UT29L+T is available at Aetrix Electronics and suitable for set-top boxes, DVD players, cable modems, portable medical monitors, and industrial control panels requiring stable component supply with guaranteed long-term manufacturability.

Supply support for MAX6456UT29L+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, and interface applications in industrial, communications, and consumer systems.

The MAX6453–MAX6456 family was engineered specifically for dual-path microprocessor supervision - combining factory-set primary rail monitoring with adjustable secondary rail detection and programmable MR timing to enable robust, user-controllable system recovery.

FAQ

What is the exact VCC reset threshold voltage for MAX6456UT29L+T?

The MAX6456UT29L+T has a factory-trimmed VCC reset threshold of 2.925V, with a guaranteed range of 2.85V to 3.00V across -40°C to +85°C. This value is encoded in the "29" suffix per Table 1 of the datasheet and applies specifically to the MAX6456UT29L+T - not inferred from adjacent variants. The threshold exhibits 60ppm/°C tempco and 2×VTH hysteresis for noise immunity.

How does the MR input behave on MAX6456UT29L+T compared to MAX6454UT29L+T?

On the MAX6456UT29L+T, the MR input controls both MROUT and RESET outputs: a short MR low pulse asserts only MROUT, while holding MR low for ≥6.72s (typical) also asserts RESET. In contrast, MAX6454UT29L+T's MR affects only MROUT - RESET remains solely VCC/RSTIN–dependent. This dual-control behavior is intrinsic to the MAX6456UT29L+T's functional design and confirmed in the Pin Description and Applications Information sections.

What is the purpose of the RSTIN pin on MAX6456UT29L+T and what voltage range can it monitor?

The RSTIN pin on MAX6456UT29L+T is a high-impedance input (±25nA bias current) to an internal comparator with a fixed 0.630V threshold. When connected to the center tap of an external resistor divider, it enables precise monitoring of secondary supply rails - supporting monitored voltages from 0.63V up to 5.5V. For example, a 1.2V core rail can be scaled using R1 = 220kΩ and R2 = 250kΩ to yield VMON_TH ≈ 1.2V, as calculated per the datasheet formula.

Does MAX6456UT29L+T guarantee valid reset output when VCC drops below 1.0V?

No - the MAX6456UT29L+T guarantees valid RESET assertion only down to VCC = 1.0V, as specified in Absolute Maximum Ratings and Electrical Characteristics. Below 1.0V, current-sinking capability degrades and output logic state is not assured. For applications requiring reset validity down to 0V, a pulldown resistor cannot be used with the open-drain MAX6456UT29L+T; instead, consider push-pull variants like MAX6455UT29L+T with external pulldown.

What are the absolute maximum ratings for the RESET and MROUT pins of MAX6456UT29L+T?

The RESET and MROUT pins of MAX6456UT29L+T are open-drain outputs rated for -0.3V to +6V when deasserted (leakage ≤1µA), and capable of sinking up to 3.2mA while asserted (VOL ≤0.4V at VCC ≥4.25V). Exceeding +6V on these pins risks permanent damage, and continuous sink current must remain within SOA limits defined by the 696mW power dissipation rating at TA = +70°C.