Analog Devices Inc./Maxim Integrated MAX6347UR44+T

Overview

MAX6347UR44+T from Maxim Integrated is an active-high push-pull microprocessor supervisory circuit designed to monitor 4.38V power supplies and assert a reset signal during brownout, power-up, and power-down events. It guarantees correct operation down to VCC = 1.2V, delivers ≤1µA supply current at +25°C, maintains ≥100ms reset timeout after VCC recovery, and features factory-trimmed reset threshold accuracy of ±2.5% over –40°C to +85°C. It is used in portable battery-powered controllers requiring ultra-low-power voltage monitoring.

For engineers reviewing the MAX6347UR44+T datasheet, MAX6347UR44+T pinout, MAX6347UR44+T application, or MAX6347UR44+T equivalent, key selection criteria include active-high push-pull output logic, 4.38V reset threshold with ±2.5% tempco, SC70/SOT23-3 package compatibility, transient immunity up to 200µs at 100mV overdrive, and guaranteed functionality at VCC ≥ 1.2V.

Technical Context

The MAX6347UR44+T implements a precision bandgap-based reset comparator with hysteresis (9.5mV) and internal timing capacitor for fixed 100–280ms reset timeout. Its active-high push-pull output drives high during VCC fault conditions and remains asserted for ≥100ms after VCC exceeds 4.38V.

It operates across –40°C to +85°C with supply current stable at ≤1.75µA at VCC = 5.5V and exhibits 40ppm/°C reset threshold temperature coefficient. The device ignores fast VCC transients ≤200µs when overdriven by 100mV below threshold, ensuring noise immunity in noisy power rails.

Key Specifications

Pinout & Package

MAX6347UR44+T is housed in a 3-pin SOT23-3 package (JEDEC MO-178AA), footprint-compatible with SC70-3, with 1.3mm × 2.9mm body size and 0.95mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6327UR44+T, the MAX6347UR44+T offers tighter supply-current specification across full VCC range and broader temperature-rated performance; versus TPS3124E18DBVR, it provides native active-high drive, lower ICC, and direct pin compatibility without external components.

Availability

MAX6347UR44+T is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, battery management systems, and smart energy meters requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6347UR44+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 industrial, automotive, and computing applications, with emphasis on power management and reliability-critical functions.

The MAX63xx family was engineered specifically for ultra-low-power microprocessor supervision in battery-operated and noise-prone embedded systems, prioritizing guaranteed reset behavior under brownout and transient conditions.

FAQ

What is the exact reset threshold voltage of MAX6347UR44+T and how tightly is it specified?

The MAX6347UR44+T has a factory-trimmed nominal reset threshold of 4.38V, with ±1.5% tolerance at +25°C and ±2.5% tolerance over the full –40°C to +85°C operating temperature range. This specification is guaranteed per the Electrical Characteristics table in the official Maxim datasheet, and the device uses bandgap-based trimming to achieve this precision without external calibration.

Does MAX6347UR44+T support active-high reset assertion, and what is its output drive capability?

Yes, MAX6347UR44+T features an active-high push-pull RESET output. When asserted (i.e., during VCC fault), it drives HIGH with ≥500µA sink capability at VCC ≥ 2.1V; when deasserted, it pulls LOW with ≤0.4V VOL at ISINK = 3.2mA and VCC ≥ 4.5V. This eliminates need for external pull-up resistors and ensures robust interfacing with µP reset inputs expecting high-active signaling.

What is the minimum VCC voltage at which MAX6347UR44+T remains functional and guarantees correct reset behavior?

MAX6347UR44+T is guaranteed to operate correctly down to VCC = 1.2V over the full –40°C to +85°C temperature range. At this voltage, it continues to monitor the supply and assert RESET appropriately, and its internal comparator remains biased and functional - a key differentiator for brownout resilience in low-voltage systems.

How long does the MAX6347UR44+T hold the reset signal after VCC recovers above the 4.38V threshold?

MAX6347UR44+T holds the active-high RESET signal for a minimum of 100ms after VCC rises above the 4.38V threshold, with typical timeout ranging from 100ms to 280ms depending on temperature and process variation. This fixed delay is generated by an internal timing capacitor and requires no external components, ensuring consistent µP initialization timing.

Is MAX6347UR44+T compatible with standard SOT23-3 PCB footprints, and what is its RoHS status?

Yes, MAX6347UR44+T uses the industry-standard 3-pin SOT23-3 package (JEDEC MO-178AA) with 0.95mm lead pitch and 1.3mm × 2.9mm body dimensions, matching common SOT23 land patterns. The "+T" suffix explicitly denotes lead-free, RoHS-compliant packaging per Maxim's ordering nomenclature, verified in the Package Information section of the datasheet.