Analog Devices Inc./Maxim Integrated MAX6348XR44

Overview

MAX6348XR44 from Maxim Integrated is an open-drain, active-low microprocessor supervisory circuit designed to monitor 4.38V power supplies and assert a reset signal during brownout or power-up/down events. It delivers ultra-low 1µA max supply current, guarantees correct operation down to VCC = 1V, provides ≥100ms reset timeout after VCC recovery, and features factory-trimmed reset threshold with ±1.5% tolerance at +25°C - used in portable battery-powered controllers requiring reliable, low-power reset assertion.

For engineers reviewing the MAX6348XR44 datasheet, MAX6348XR44 pinout, MAX6348XR44 application, or MAX6348XR44 equivalent, key selection criteria include its open-drain RESET output compatibility with bidirectional µP reset pins (e.g., Motorola 68HC11), immunity to fast VCC transients ≤200µs at 4.38V threshold overdrive, and SC70-3 package suitability for space-constrained embedded designs.

Technical Context

The MAX6348XR44 implements a precision voltage comparator with hysteresis (9.5mV typical) to detect when VCC falls below its factory-set 4.38V reset threshold. Its internal circuitry holds RESET low for ≥100ms after VCC rises above VTH, ensuring stable µP initialization. The comparator ignores transients up to 200µs duration when VCC dips 100mV below VTH - critical for noisy automotive or industrial power rails.

This device operates across -40°C to +85°C with full specification of reset threshold tempco (40ppm/°C), supply current stability (<1µA at +25°C), and reset timeout consistency. Its open-drain output requires an external pull-up resistor and supports wired-OR configurations, enabling shared reset bus architectures in multi-controller systems.

Key Specifications

Pinout & Package

MAX6348XR44 is housed in a 3-pin SC70 package (2.0mm × 2.1mm × 0.9mm), optimized for high-density PCB layouts. Pin 1 is GND, Pin 2 is open-drain RESET output, and Pin 3 is VCC input - compatible with SOT23-3 footprint for layout reuse.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6348XR44, MAX6328UR44-T offers identical functionality in a larger SOT23 package - suitable for legacy layouts - while TPS3808G33DBVR provides higher ICC and fixed 3.3V threshold in a non-pin-compatible 6-pin format, limiting drop-in replacement viability.

Availability

MAX6348XR44 is available at Aetrix Electronics and suitable for industrial controllers, automotive body electronics, and portable medical sensors requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature.

Supply support for MAX6348XR44 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) is a semiconductor company specializing in analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX63xx family was designed specifically for ultra-low-power, precision voltage monitoring in microprocessor-based systems - emphasizing reset reliability, minimal external components, and compact packaging for space- and energy-constrained applications.

FAQ

What is the exact reset threshold voltage of MAX6348XR44 and how tightly is it specified?

The MAX6348XR44 has a factory-trimmed reset threshold of 4.38V, with ±1.5% tolerance at +25°C and ±2.5% over the full -40°C to +85°C operating range. This value is laser-trimmed during production and verified per Maxim's datasheet Table 1, ensuring precise match to 4.3V–4.4V supply rails without external calibration. The MAX6348XR44 maintains this accuracy across temperature via a 40ppm/°C tempco design.

Does MAX6348XR44 support operation at VCC below 2.0V, and what happens to reset behavior?

Yes, MAX6348XR44 is fully guaranteed to operate correctly down to VCC = 1.0V - including accurate reset assertion and hold timing. Below 2.0V, the internal comparator remains functional, and RESET stays asserted until VCC rises above 4.38V and sustains ≥100ms. This enables safe shutdown sequencing in battery-depleted systems. The MAX6348XR44's 1µA max ICC ensures minimal drain even at sub-1.5V operation.

Can MAX6348XR44 be used with a 3.3V microcontroller that has a bidirectional reset pin?

Yes, MAX6348XR44's open-drain RESET output is explicitly designed for interfacing with bidirectional µP reset pins like those on Motorola 68HC11 or STM32L4 series. Connect the MAX6348XR44 RESET pin to the µC's reset pin via a single external pull-up resistor (e.g., 10kΩ to 3.3V). Either device can then assert reset - the MAX6348XR44 pulls low during brownout, and the µC can drive low for software-initiated reset.

What is the maximum transient duration that MAX6348XR44 will ignore at its 4.38V threshold?

Per the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in the MAX6348XR44 datasheet, the device rejects negative-going VCC transients up to 200µs in duration when VCC dips 100mV below the 4.38V threshold (i.e., to 4.28V). This immunity is inherent to the comparator's internal filtering and does not require external RC networks - a key advantage in electrically noisy automotive or industrial settings where the MAX6348XR44 is commonly deployed.

Is MAX6348XR44 available in both leaded and lead-free packaging, and how is this indicated in the part number?

Yes, MAX6348XR44 is offered in both leaded and lead-free versions. The standard part number MAX6348XR44-T denotes leaded packaging; to specify lead-free, replace the "-T" suffix with "+T", resulting in MAX6348XR44+T. Both variants use the same SC70-3 package outline and electrical specifications, with lead-free compliance meeting JEDEC J-STD-020 moisture sensitivity level 1 (MSL1) requirements. Traceability and RoHS documentation are provided for MAX6348XR44+T upon request.