Analog Devices Inc./Maxim Integrated MAX803MEXR

Overview

MAX803MEXR from Maxim Integrated is a precision microprocessor supervisory circuit with open-drain active-low RESET output, designed to monitor +4.38V supply rails in embedded systems. It asserts reset when VCC falls below 4.38V (±1.5% over −40°C to +125°C), holds reset for ≥140ms after VCC recovers, and operates down to VCC = 1V with 12µA supply current. Used in portable equipment, automotive controllers, and industrial µC power monitoring.

For engineers reviewing the MAX803MEXR datasheet, MAX803MEXR pinout, MAX803MEXR application, or MAX803MEXR equivalent, this page delivers verified technical context, exact SC70-3 package mapping, confirmed reset threshold accuracy, transient immunity specs, and validated alternatives for reset supervisor selection in battery-powered and high-reliability systems.

Technical Context

The MAX803MEXR implements a precision bandgap-based voltage comparator with internal hysteresis to detect VCC drops below its 4.38V threshold. Its open-drain output requires an external pull-up resistor-supporting level-shifting to higher-voltage logic domains-and remains functional down to VCC = 1V, ensuring valid reset assertion during deep brownout conditions.

Reset timeout is guaranteed ≥140ms across −40°C to +125°C (SC70 package), with temperature coefficient of only 30ppm/°C. The device rejects fast transients: a 100mV VCC dip lasting ≤20µs at +25°C does not trigger spurious reset, enabling robust operation in noisy power environments.

Key Specifications

Pinout & Package

MAX803MEXR is housed in a 3-pin SC70-3 package (JEDEC MO-203AA), measuring 2.0mm × 2.1mm × 0.9mm, rated for −40°C to +125°C operation. Pin 1 is RESET (open-drain), Pin 2 is GND, Pin 3 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX803MEXR, MAX809MEXR simplifies design by removing the pull-up resistor but sacrifices voltage-level flexibility, while TPS3808G18DBVR offers superior accuracy and lower current at the cost of non-interchangeable packaging and pinout-making MAX803MEXR optimal for legacy-compatible, multi-rail, low-power designs.

Availability

MAX803MEXR is available at Aetrix Electronics and suitable for automotive engine control units, portable medical monitors, and industrial PLC I/O modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX803MEXR 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 high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX803 family was engineered as ultra-low-power, precision reset supervisors targeting battery-operated and thermally demanding applications-prioritizing threshold accuracy, wide temperature operation, and minimal external components.

FAQ

What is the exact reset threshold voltage of MAX803MEXR and how stable is it over temperature?

The MAX803MEXR has a nominal reset threshold of 4.38V with ±1.5% tolerance over −40°C to +125°C. Its temperature coefficient is tightly controlled at 30ppm/°C, meaning threshold drift is less than 0.013V across the full range-ensuring predictable reset behavior in automotive and industrial environments where thermal stress is severe. This stability is confirmed in the device's Electrical Characteristics table and Typical Operating Characteristics plots.

Does MAX803MEXR require an external pull-up resistor, and what value is recommended?

Yes, MAX803MEXR requires an external pull-up resistor on its open-drain RESET pin because it cannot drive high actively. A 10kΩ to 100kΩ resistor pulled to the target logic voltage (≤6V) is recommended-100kΩ is typical for low-current applications like battery-powered devices, while 10kΩ suits faster edge rates in noisy environments. The datasheet confirms this requirement in both the General Description and Applications Information sections.

Can MAX803MEXR operate reliably when VCC drops below 1V?

No-MAX803MEXR guarantees correct RESET logic state only down to VCC = 1V. Below that, the internal circuitry cannot maintain defined output behavior. However, the device *does* assert RESET correctly as VCC falls *to* 1V and holds it asserted throughout the decay, satisfying fail-safe requirements for most µPs. This 1V lower limit is explicitly stated in the Absolute Maximum Ratings and Detailed Description sections of the datasheet.

What package type and dimensions does MAX803MEXR use, and is it RoHS-compliant?

MAX803MEXR uses the SC70-3 package (JEDEC MO-203AA), measuring 2.0mm × 2.1mm × 0.9mm with a 0.65mm pin pitch. It is available in both leaded and lead-free versions; the "+T" suffix denotes RoHS-compliant lead-free packaging. The Ordering Information section confirms SC70-3 as the sole package for MAX803 variants and specifies lead-free ordering via suffix replacement.

How does MAX803MEXR handle fast power supply transients, and what is its immunity specification?

MAX803MEXR rejects short negative-going VCC transients: at +25°C, it ignores dips of ≤100mV lasting ≤20µs, as shown in Figure 1 of the datasheet. This immunity stems from internal comparator hysteresis and filtering-preventing false resets during relay switching or motor commutation noise. The device's transient rejection is quantified across temperature and overdrive levels in the Electrical Characteristics table under "Power-Down Reset Delay."