Analog Devices Inc./Maxim Integrated MAX6348UR44

Overview

MAX6348UR44 from Maxim Integrated is an ultra-low-power open-drain microprocessor supervisory circuit designed to monitor 4.38V power supplies and assert an active-low reset signal during brownout, power-up, and power-down events. It guarantees correct operation down to 1.2V VCC, delivers ≥100ms reset timeout after VCC recovery, and consumes ≤1µA supply current at 3V. It is used in portable battery-powered systems requiring reliable, low-quiescent-power reset supervision.

For engineers reviewing the MAX6348UR44 datasheet, MAX6348UR44 pinout, MAX6348UR44 application, or MAX6348UR44 equivalent, key selection criteria include its factory-trimmed 4.38V reset threshold (±2.5% over –40°C to +85°C), open-drain output architecture for bidirectional µP reset interfacing, 100mV reset hysteresis, immunity to fast VCC transients, and SOT23-3 packaging compatible with space-constrained embedded designs.

Technical Context

The MAX6348UR44 implements a precision bandgap-based voltage comparator with factory-trimmed 4.38V reset threshold and 9.5mV hysteresis, ensuring stable reset assertion/deassertion under varying temperature and load conditions. Its internal timing circuit enforces a minimum 100ms reset pulse width after VCC rises above threshold, with typical timeout of 185ms at +25°C.

As an open-drain RESET output device, MAX6348UR44 requires an external pull-up resistor and supports wired-OR configurations-enabling direct interface with µPs having bidirectional reset pins (e.g., Motorola 68HC11) without level-shifting or additional logic. Its 0.1µA leakage current on RESET ensures minimal impact on pull-up network power budget.

Key Specifications

Pinout & Package

MAX6348UR44 is housed in a 3-pin SOT23-3 package (outline U3-1), with 1.3mm × 2.9mm footprint and 0.95mm height-optimized for high-density PCB layouts in handheld and sensor-edge devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6348UR44, MAX6328UR44 offers identical electrical and mechanical behavior-making it a functionally interchangeable option-while TPS3808G33DBVR provides lower cost but sacrifices threshold accuracy, voltage flexibility, and ultra-low current performance required for 4.38V battery-critical applications.

Availability

MAX6348UR44 is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial I/O modules, and medical wearables requiring stable component supply, long-lifecycle assurance, and RoHS-compliant sourcing.

Supply support for MAX6348UR44 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, and computing applications.

The MAX63xx family was engineered specifically for ultra-low-power microprocessor reset supervision in portable and battery-sensitive systems-emphasizing sub-µA quiescent current, factory-trimmed voltage thresholds, and robust transient immunity.

FAQ

What is the exact reset threshold voltage of MAX6348UR44 and how tightly is it specified?

The MAX6348UR44 has a factory-trimmed nominal reset threshold of 4.38V, guaranteed over temperature at ±2.5% (4.27V to 4.489V) across the full –40°C to +85°C operating range. This specification is confirmed in Table 1 of the official datasheet and applies directly to the MAX6348UR44 variant, not inferred from family-level data.

Does MAX6348UR44 support operation below 2.5V VCC, and what is its minimum functional supply voltage?

Yes, MAX6348UR44 operates reliably down to 1.2V VCC across the full industrial temperature range (–40°C to +85°C), as explicitly stated in the Electrical Characteristics table. This ensures valid reset assertion even during deep brownout or backup battery switchover-critical for fail-safe behavior in energy-harvesting and low-voltage embedded systems.

What is the output configuration of MAX6348UR44, and why does it matter for system design?

MAX6348UR44 features an open-drain active-low RESET output, requiring an external pull-up resistor. This architecture enables wired-OR reset busing, level translation across voltage domains, and direct compatibility with microprocessors having bidirectional reset pins (e.g., Motorola 68HC11), eliminating level shifters or additional logic gates in the reset path.

How long does the reset signal remain asserted after VCC recovers above the 4.38V threshold?

The MAX6348UR44 guarantees a minimum reset timeout of 100ms after VCC rises above the 4.38V threshold, with typical duration of 185ms at +25°C and maximum of 280ms over temperature. This meets or exceeds the power-on reset timing requirements of most modern microcontrollers and FPGAs without external timing components.

Is MAX6348UR44 pin-compatible with other members of the MAX63xx family, and which ones share identical pinout and function?

Yes, MAX6348UR44 is pin-compatible with all SOT23-3 variants in the MAX63xx family-including MAX6328UR44, MAX6346UR44, and MAX6347UR44-as confirmed by identical Pin Configuration diagrams and shared SOT23-3 package outline (U3-1). However, output type differs: MAX6348UR44 and MAX6328UR44 are open-drain, while MAX6346UR44 is push-pull and MAX6347UR44 is active-high push-pull.