Analog Devices Inc./Maxim Integrated MAX803ZEXR

Overview

The MAX803ZEXR from Maxim Integrated is a 3-pin SC70-packaged microprocessor supervisory circuit with open-drain active-low RESET output, precision 2.32V reset threshold (±1.5% over −40°C to +125°C), 140ms minimum reset timeout, 12µA supply current at +25°C, and guaranteed reset validity down to VCC = 1V - used for reliable power-on/brownout reset assertion in +2.5V digital systems.

For engineers reviewing the MAX803ZEXR datasheet, MAX803ZEXR pinout, MAX803ZEXR application, or MAX803ZEXR equivalent, key selection considerations include its SC70-3 package, open-drain output requiring external pull-up, −40°C to +125°C operating range, compatibility with 2.5V supply rails, and immunity to fast VCC transients up to 20µs at 100mV overdrive.

Technical Context

The MAX803ZEXR implements a precision voltage comparator monitoring VCC against a trimmed bandgap reference to trigger reset when supply drops below 2.32V. Its internal timing circuit ensures a minimum 140ms reset pulse width after VCC recovers above threshold, with temperature-compensated reset delay and 30ppm/°C tempco.

Designed for minimal external components, it operates without trimming or external capacitors. The open-drain RESET output supports level-shifting and bidirectional µP reset interfaces, sinking ≥1.2mA at VCC ≥ 2.5V while remaining functional down to VCC = 1V.

Key Specifications

Pinout & Package

MAX803ZEXR is housed in a 3-pin SC70-3 package (1.25mm × 2.1mm, 0.65mm pitch) with exposed pad option not applicable. Pin 1 is RESET (open-drain), Pin 2 is GND, and Pin 3 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX803ZEXR, MAX809ZEXR simplifies design by removing the pull-up requirement but sacrifices interface flexibility, while TPS3808G12DBVR offers superior accuracy and lower current at the cost of reduced temperature capability and missing deep-brownout support.

Availability

MAX803ZEXR is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, portable medical monitors, smart energy meters, and battery-powered instrumentation requiring stable component supply across extended temperature ranges.

Supply support for MAX803ZEXR 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 MAX803 family delivers highly accurate, low-power microprocessor supervisory circuits optimized for reliable reset generation in space-constrained, wide-temperature embedded systems using 2.5V–5V supplies.

FAQ

What is the exact reset threshold voltage of the MAX803ZEXR and how tightly is it specified?

The MAX803ZEXR has a nominal reset threshold of 2.32V, specified with ±1.5% tolerance over the full −40°C to +125°C temperature range. This value is trimmed during production and confirmed in the Electrical Characteristics table for SC70-packaged Z-grade parts. The MAX803ZEXR's threshold is optimized for 2.5V supply rails, asserting reset when VCC falls 7% below nominal.

Does the MAX803ZEXR require an external pull-up resistor, and if so, what value is recommended?

Yes, the MAX803ZEXR requires an external pull-up resistor on its open-drain RESET pin. A 10kΩ to 100kΩ resistor to VCC (or another compatible supply up to +6V) is recommended. Typical designs use 47kΩ for noise immunity and drive strength balance. The MAX803ZEXR itself does not integrate this resistor, distinguishing it from push-pull variants like MAX809ZEXR.

What is the minimum VCC voltage at which the MAX803ZEXR guarantees correct RESET output behavior?

The MAX803ZEXR guarantees valid RESET output state down to VCC = 1V. Below this, the internal circuitry cannot maintain defined logic levels. This feature ensures deterministic reset assertion during deep brownout events common in automotive and battery-operated systems, a key differentiator from many competing supervisors rated only to VCC = 1.2V or higher.

Can the MAX803ZEXR be used with supply voltages other than 2.5V?

Yes, the MAX803ZEXR operates with VCC from 1.2V to 5.5V and monitors that same rail. While its 2.32V threshold is optimized for 2.5V systems, it remains functional with +3.0V, +3.3V, or +5V supplies - though reset will trigger earlier relative to nominal voltage. For example, on a +3.3V rail, reset asserts at ~30% undervoltage rather than 7%, which may be acceptable in overvoltage-tolerant designs.

What package type and dimensions does the MAX803ZEXR use, and is it RoHS-compliant?

The MAX803ZEXR uses the SC70-3 package (1.25mm × 2.1mm body, 0.65mm lead pitch) with JEDEC MO-203AC outline. It is available in both leaded and lead-free versions; the standard orderable part MAX803ZEXR-T is lead-free (RoHS-compliant), with leaded versions requiring factory consultation. Thermal performance is characterized for 174mW max power dissipation at +70°C ambient.