Analog Devices Inc./Maxim Integrated MAX6326UR31-

Overview

MAX6326UR31-T from Maxim Integrated is an ultra-low-power, active-low push-pull microprocessor supervisory circuit designed to monitor 3.3V power supplies and assert a reset signal during brownout or power-up conditions. It features a factory-trimmed 3.08V reset threshold (±2.5% over -40°C to +85°C), 100ms minimum reset timeout, 1µA max supply current at 3V, and operates down to 1.2V VCC. It is used in portable battery-powered systems requiring reliable power-on reset with minimal quiescent current.

For engineers reviewing the MAX6326UR31-T datasheet, MAX6326UR31-T pinout, MAX6326UR31-T application, or MAX6326UR31-T equivalent, key selection criteria include reset threshold accuracy, push-pull output drive capability, SOT23-3 package compatibility, transient immunity, and guaranteed operation down to 1.2V - all critical for embedded µP reset integrity in space-constrained, low-power designs.

Technical Context

The MAX6326UR31-T implements a precision bandgap-based voltage comparator with hysteresis (6.3mV) to detect VCC drops below its 3.08V threshold and maintain RESET assertion for ≥100ms after recovery. Its internal timing circuit ensures deterministic power-on reset behavior independent of external components.

It uses a push-pull output stage capable of sourcing 500µA at 0.8·VCC and sinking 1.6mA at ≤0.3V, eliminating need for external pull-up resistors. The device ignores fast VCC transients (e.g., <20µs negative glitches at 100mV overdrive), enhancing noise immunity in noisy digital environments.

Key Specifications

Pinout & Package

MAX6326UR31-T is housed in a 3-pin SOT23-3 package (package code U3-1), with 1.3mm × 2.9mm footprint and 0.95mm height - compatible with high-density PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD2-T and TPS3808G30DBVR, the MAX6326UR31-T uniquely combines 1µA max supply current, guaranteed 1.2V operation, and push-pull output in a standard SOT23-3 - making it optimal for battery-critical, space-constrained 3.3V systems where reset reliability must persist through deep brownout.

Availability

MAX6326UR31-T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart energy meters, and automotive body control units requiring stable component supply, long-lifecycle availability, and RoHS-compliant sourcing.

Supply support for MAX6326UR31-T 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, communications, and consumer applications.

The MAX6326 family delivers ultra-low-power, precision voltage supervision for microprocessor reset in battery-powered and space-constrained systems - emphasizing accuracy, reliability, and minimal external component count.

FAQ

What is the exact reset threshold voltage of MAX6326UR31-T and how does it vary with temperature?

The MAX6326UR31-T has a nominal reset threshold of 3.08V at +25°C, with ±1.5% tolerance at room temperature and ±2.5% over the full -40°C to +85°C operating range. Its tempco is 40ppm/°C, resulting in ≤15mV total drift across temperature - verified per Electrical Characteristics table in the official datasheet. This ensures consistent 3.3V supply monitoring in varying environmental conditions.

Does MAX6326UR31-T require any external components to function?

No, the MAX6326UR31-T requires zero external components. Its precision voltage reference, comparator, timer, and push-pull output driver are fully integrated. Unlike open-drain supervisors, it needs no pull-up resistor. The only connections are VCC, GND, and RESET - enabling minimal footprint and simplified design validation for the MAX6326UR31-T.

Can MAX6326UR31-T operate reliably during deep brownout conditions?

Yes, the MAX6326UR31-T is guaranteed to maintain correct reset state down to 1.2V VCC - well below typical 3.3V rail collapse points. Its internal circuitry remains functional and asserts RESET correctly even as VCC decays from 3.3V to 1.2V, making it suitable for systems with backup capacitors or dual-supply handover where sustained reset integrity is critical for the MAX6326UR31-T.

What is the reset timeout duration of MAX6326UR31-T and is it adjustable?

The MAX6326UR31-T provides a fixed minimum reset timeout of 100ms after VCC rises above the 3.08V threshold - with typical values of 185ms and maximum of 280ms. This timing is internally generated and non-adjustable, eliminating variability from external RC networks. The guaranteed 100ms minimum ensures robust µP initialization across all process, voltage, and temperature corners for the MAX6326UR31-T.

Is MAX6326UR31-T pin-compatible with other common reset ICs like MAX809?

Yes, the MAX6326UR31-T shares identical pinout (GND, RESET, VCC), package (SOT23-3), and footprint with MAX809 series devices. However, it differs in supply current (1µA vs. 2.5µA), VCC operating range (1.2V–5.5V vs. 1.0V–6.0V), and reset threshold tolerance (±2.5% vs. ±2.0%). These differences make the MAX6326UR31-T a direct replacement where ultra-low ICC and guaranteed 1.2V operation are prioritized.