Analog Devices Inc./Maxim Integrated MAX6331TUR+

Overview

The MAX6331TUR+ from Maxim Integrated is a precision shunt regulator with integrated active-high power-on reset function in a 3-pin SOT23-3 package. It delivers ±1.5% output voltage tolerance (3.3V nominal), 140ms reset timeout, and operates across -40°C to +85°C. Designed for microprocessor-based systems powered from high-voltage sources, it protects against power-up, brownout, and power-down faults in size-constrained applications.

For engineers reviewing the MAX6331TUR+ datasheet, MAX6331TUR+ pinout, MAX6331TUR+ application, or MAX6331TUR+ equivalent, key selection criteria include shunt voltage accuracy (±1.5%), reset threshold stability (±1.5% over temperature), guaranteed 140ms reset pulse width, and compatibility with µP reset inputs requiring active-high assertion and low quiescent current operation.

Technical Context

The MAX6331TUR+ integrates a precision shunt regulator and a reset generator with internal 140ms timeout timer. Its shunt regulation maintains VSHUNT at 3.3V ±1.5% over 100µA–50mA load current and -40°C to +85°C, with 40ppm/°C tempco. The active-high RESET output asserts high only after VSHUNT exceeds 3.06V and remains high for ≥140ms post-threshold crossing.

It uses a single external series resistor (RS) to set input current, enabling operation from VIN up to 50V. The device's push/pull output drives µP reset pins directly without pull-up resistors, and its GND-referenced SHUNT pin simplifies layout while supporting bypass capacitor stabilization (CL ≥ 0.03µF).

Key Specifications

Pinout & Package

SOT23-3 package with gull-wing leads, 2.9mm × 1.6mm body, 0.95mm height, and 0.95mm lead pitch. RoHS-compliant lead-free construction denoted by "+" suffix.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt-regulator-with-reset applications.

Compared with MAX6330TUR+, the MAX6331TUR+ provides active-high reset polarity essential for modern low-voltage µPs, while TLV7031DBVR lacks integrated regulation and fixed timing-making MAX6331TUR+ the optimal choice for compact, production-ready µP supervision where 3.3V regulation and 140ms reset are required.

Availability

MAX6331TUR+ is available at Aetrix Electronics and suitable for smart home controllers, portable medical monitors, and industrial PLC I/O modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6331TUR+ 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 and mixed-signal ICs for industrial, communications, and consumer applications, emphasizing high reliability and integration.

The MAX6330/MAX6331 family targets cost-sensitive, space-constrained µP supervision needs-delivering combined shunt regulation and reset in minimal footprint for embedded control and portable electronics.

FAQ

What is the regulated shunt voltage of the MAX6331TUR+?

The MAX6331TUR+ provides a precisely regulated shunt voltage of 3.3V with ±1.5% tolerance over temperature (-40°C to +85°C) and shunt current (100µA to 50mA). This value is confirmed by the "T" suffix in the part number and verified in the Electrical Characteristics table under MAX633_T conditions.

Does the MAX6331TUR+ require external components to generate its reset signal?

No, the MAX6331TUR+ does not require external components to generate its reset signal. It features an internal 140ms timeout timer that guarantees the active-high RESET output remains asserted for ≥140ms after V_SHUNT rises above 3.06V, eliminating the need for external RC networks or timing capacitors.

Can the MAX6331TUR+ operate from a 50V input source?

Yes, the MAX6331TUR+ can operate from input voltages up to 50V, as specified in the Absolute Maximum Ratings. Its operation depends on proper selection of the external series resistor RS to limit shunt current within 100µA–50mA, ensuring safe power dissipation and regulation stability at high VIN.

What is the minimum bypass capacitor required for stable operation of the MAX6331TUR+?

The minimum bypass capacitor (CL) required for stable operation of the MAX6331TUR+ is 0.03µF, as stated in the Applications Information section. Using less than this value risks oscillation or overshoot during load transients; typical designs use 0.1µF ceramic capacitors placed close to the SHUNT pin.

How does the MAX6331TUR+ differ from the MAX6330TUR+?

The MAX6331TUR+ differs from the MAX6330TUR+ solely in reset output polarity: MAX6331TUR+ provides active-high RESET, while MAX6330TUR+ provides active-low RESET. All other specifications-including V_SHUNT, V_TH, timing, package, and temperature range-are identical between the two devices.