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 conditions. It delivers ultra-low 1µA max supply current, guarantees correct operation down to 1V VCC, and provides ≥100ms reset timeout after VCC rises above threshold. Used in portable battery-powered systems requiring precise voltage supervision with minimal quiescent power.

For engineers reviewing the MAX6348XR44+ datasheet, MAX6348XR44+ pinout, MAX6348XR44+ application, or MAX6348XR44+ equivalent, this page details its reset threshold accuracy (±1.5% at +25°C), SC70-3 package compatibility, transient immunity up to 200µs at 100mV overdrive, and direct interface capability with bidirectional µP reset pins such as Motorola 68HC11.

Technical Context

The MAX6348XR44+ implements a precision bandgap-based voltage comparator with factory-trimmed 4.38V reset threshold (±1.5% at +25°C, ±2.5% over –40°C to +85°C) and 9.5mV hysteresis. Its open-drain RESET output requires an external pull-up and supports bidirectional reset assertion with microcontrollers like the 68HC11.

It features built-in immunity to fast VCC transients-rejecting negative glitches up to 200µs duration when VCC dips 100mV below threshold-and operates across full industrial temperature range (–40°C to +85°C) with supply current stable at ≤1µA over temperature.

Key Specifications

Pinout & Package

MAX6348XR44+ is housed in a 3-pin SC70 package (2.0mm × 2.1mm × 0.9mm), compatible with SOT23-3 footprint and reflow assembly. The compact outline supports high-density PCB layouts in space-constrained portable designs.

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 supervision functionality in a larger SOT23 package, while TPS3808G33DBVR targets different voltage rails and output drive architecture-neither is pin-compatible, and both require schematic and layout review before substitution.

Availability

MAX6348XR44+ is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, industrial handheld scanners, and smart energy meters requiring stable component supply with guaranteed long-term availability and lead-free compliance.

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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing markets.

The MAX63xx family was engineered specifically for ultra-low-power microprocessor reset supervision in battery-critical and thermally demanding applications-emphasizing sub-1µA operation, factory-trimmed precision, and robust transient rejection.

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, specified as ±1.5% at +25°C and ±2.5% over the full –40°C to +85°C operating temperature range. This precision eliminates need for external resistive dividers or calibration, and the 9.5mV hysteresis prevents chatter near threshold. The value is laser-trimmed at wafer test and confirmed per Table 1 in the official MAX6348 datasheet.

Does MAX6348XR44+ support operation below 2.5V, and what is its minimum functional VCC?

Yes, MAX6348XR44+ is fully functional down to 1.0V VCC-guaranteed by design across temperature. This enables use in deep brownout detection scenarios and ensures the reset output remains valid even during severe undervoltage events where other supervisors may release prematurely. The internal comparator and bias circuitry maintain correct state down to 1V, as verified in Absolute Maximum Ratings and Electrical Characteristics sections.

What package type and dimensions does MAX6348XR44+ use, and is it compatible with automated assembly?

MAX6348XR44+ uses the SC70-3 package: 2.0mm × 2.1mm × 0.9mm body size with standard 0.65mm lead pitch. It is supplied in tape-and-reel format (EIA-481 compliant) and fully compatible with standard SMT pick-and-place equipment and reflow soldering profiles-including lead-free (RoHS-compliant) thermal cycles. The marking "FZCI" appears on top for traceability.

How does the open-drain output of MAX6348XR44+ interface with microcontrollers having bidirectional reset pins?

The open-drain RESET output of MAX6348XR44+ connects directly to bidirectional µP reset pins (e.g., Motorola 68HC11) using a single external pull-up resistor. This allows either the MAX6348XR44+ or the µP to assert reset-enabling coordinated system-level recovery. No level-shifting or additional logic is needed, and the design avoids contention that would occur with push-pull outputs.

What is the maximum transient duration that MAX6348XR44+ can ignore without asserting reset?

At a 100mV overdrive (i.e., VCC dipping 100mV below 4.38V threshold), MAX6348XR44+ ignores transients up to 200µs-per the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in the datasheet. This immunity prevents false resets caused by switching noise or brief load surges, and the rejection window tightens as overdrive increases (e.g., 50µs at 200mV overdrive).