Analog Devices Inc./Maxim Integrated MAX6348UR40

Overview

MAX6348UR40 from Maxim Integrated is an open-drain, active-low microprocessor supervisory circuit designed to monitor 4.0V power supplies and assert reset during brownout or power-up/down events. It delivers 1µA max supply current, 100ms minimum reset timeout, and factory-trimmed 4.0V reset threshold with ±1.5% accuracy at +25°C - used in portable battery-powered systems requiring ultra-low-power supply monitoring.

For engineers reviewing the MAX6348UR40 datasheet, MAX6348UR40 pinout, MAX6348UR40 application, or MAX6348UR40 equivalent, this page provides verified technical context, pin-level design meaning, real-world use scenarios, and validated alternative options for µP reset circuit selection in space-constrained, low-quiescent-current designs.

Technical Context

The MAX6348UR40 implements a precision voltage comparator with hysteresis (9.5mV) and internal timing circuitry to guarantee ≥100ms reset assertion after VCC rises above the 4.0V threshold. Its open-drain RESET output enables bidirectional reset interfacing with µPs like the Motorola 68HC11 using a single external pull-up resistor.

It operates across -40°C to +85°C, maintains valid reset state down to VCC = 1V, and rejects fast transients via built-in immunity - with maximum glitch rejection duration decreasing as VCC dip magnitude increases beyond the reset threshold overdrive window.

Key Specifications

Pinout & Package

MAX6348UR40 is housed in a 3-pin SOT23-3 package (JEDEC MO-178AA), with 1.3mm × 2.9mm footprint and 1.45mm height - optimized for high-density PCB layouts in handheld and sensor modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TR40D3T and TPS3808G33DBVR, the MAX6348UR40 uniquely combines open-drain flexibility, lowest ICC (1µA), and factory-trimmed 4.0V accuracy - making it optimal for battery-sensitive, multi-device reset buses where layout simplicity and long service life are critical.

Availability

MAX6348UR40 is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, industrial data loggers, smart energy meters, and battery-powered instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for MAX6348UR40 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, mixed-signal, and power-management ICs for industrial, automotive, communications, and computing markets.

The MAX63xx family targets ultra-low-power microprocessor supervision - delivering pin-compatible, factory-trimmed reset solutions that eliminate external components while ensuring robust operation across harsh thermal and electrical environments.

FAQ

What is the exact reset threshold voltage of MAX6348UR40 and how tightly is it specified?

The MAX6348UR40 has a factory-trimmed reset threshold of 4.0V, with ±1.5% tolerance at +25°C and ±2.5% over the full -40°C to +85°C temperature range. This specification is guaranteed by production test and documented in the Electrical Characteristics table of the official datasheet - ensuring predictable brownout detection without external calibration for the MAX6348UR40.

Does MAX6348UR40 support operation down to 1V supply, and what happens to the reset output below that?

Yes, the MAX6348UR40 is guaranteed to maintain correct reset state (RESET asserted low) for VCC down to 1.0V. Below 1.0V, the device is outside Absolute Maximum Ratings - operation is not characterized, and the RESET output may become undefined. The 1.0V lower limit ensures reliable behavior during deep brownout recovery, a key feature of the MAX6348UR40.

Can MAX6348UR40 be used with a 5V microcontroller that has a bidirectional reset pin?

Yes - the MAX6348UR40's open-drain RESET output is specifically designed for this use case. Connect the MAX6348UR40 RESET pin to the µC's bidirectional reset pin with a single external pull-up resistor (e.g., 10kΩ to 5V). Either the MAX6348UR40 or the µC can then drive the line low to initiate reset, enabling clean handshaking in systems like the Motorola 68HC11 - a core capability of the MAX6348UR40.

What is the maximum transient duration the MAX6348UR40 can ignore at a 200mV overdrive condition?

At a VCC dip of 200mV below the 4.0V threshold (i.e., VCC = 3.8V), the MAX6348UR40 can ignore transients up to 200µs in duration, per the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in the datasheet. This immunity prevents false resets caused by brief noise spikes - a verified performance characteristic of the MAX6348UR40 under defined test conditions.

Is MAX6348UR40 available in both leaded and lead-free packaging, and how is lead-free denoted in the part number?

Yes, MAX6348UR40 is offered in both leaded and lead-free versions. The standard part number MAX6348UR40-T indicates leaded packaging; to specify lead-free, replace the "-T" suffix with "+T", resulting in MAX6348UR40+T. Both variants use the same SOT23-3 package and share identical electrical specifications - the MAX6348UR40+T meets RoHS and JEDEC J-STD-020 reflow requirements.