Analog Devices Inc./Maxim Integrated MAX6331LUR-T

Overview

The MAX6331LUR-T from Analog Devices is a precision shunt regulator with integrated active-high power-on reset functionality in a 3-pin SOT23-3 package. It delivers a regulated 5.0V shunt voltage (±1.5% tolerance), asserts RESET high for 140ms after V_SHUNT exceeds 4.63V, and operates across –40°C to +85°C - enabling reliable µP supervision in high-voltage microcontroller systems such as industrial controllers and portable instrumentation.

For engineers reviewing the MAX6331LUR-T datasheet, MAX6331LUR-T pinout, MAX6331LUR-T application, or MAX6331LUR-T equivalent, key selection criteria include its 5.0V shunt regulation, 4.63V reset threshold with 40ppm/°C tempco, 100µA–50mA shunt current range, push/pull active-high RESET output, and SOT23-3 footprint compatibility with space-constrained embedded designs.

Technical Context

The MAX6331LUR-T integrates a two-terminal shunt regulator and a dedicated reset generator with internal 140ms timeout timer. Its shunt regulation relies on a pass transistor controlled by an internal reference, maintaining V_SHUNT at 5.0V ±1.5% over 100µA–50mA load current and –40°C to +85°C ambient.

Reset assertion is triggered when V_SHUNT rises above 4.63V (±1.5%), and the active-high RESET output remains high for exactly 140ms post-threshold crossing - no external capacitor required. The device exhibits 40ppm/°C tempco on both V_SHUNT and V_TH, ensuring stable trip points across temperature.

Key Specifications

Pinout & Package

MAX6331LUR-T uses a 3-pin SOT23-3 package with exposed pad (U3+1 outline). Pin 1 is GND, Pin 2 is RESET (active-high), and Pin 3 is SHUNT - all pins are surface-mount compatible and rated for continuous short-circuit operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70733PDBVR and MAX6326LUR+T, the MAX6331LUR-T uniquely combines 5.0V shunt regulation, active-high RESET, and 140ms timeout in one SOT23-3 device - simplifying design for high-VIN µP systems where logic polarity and integration level are critical.

Availability

MAX6331LUR-T is available at Aetrix Electronics and suitable for industrial controllers, portable instrumentation, and household appliances requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6331LUR-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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA.

The MAX6330/MAX6331 family targets cost-sensitive, space-constrained µP supervisory applications requiring combined voltage regulation and reset generation - especially where high input voltage tolerance and minimal external components are essential.

FAQ

What is the exact shunt voltage and reset threshold for MAX6331LUR-T?

The MAX6331LUR-T provides a nominal shunt voltage (V_SHUNT) of 5.0V with ±1.5% tolerance over –40°C to +85°C, and a reset threshold (V_TH) of 4.63V ±1.5%. These values are factory-trimmed and specified in the Electrical Characteristics table of the official Analog Devices datasheet for MAX6331LUR-T. Both parameters exhibit 40ppm/°C temperature coefficient, ensuring predictable performance across operating conditions.

Does MAX6331LUR-T require external components to generate the reset pulse?

No, MAX6331LUR-T does not require external components to generate the reset pulse. Its internal timer provides a guaranteed 140ms reset timeout period after V_SHUNT exceeds the 4.63V threshold. This eliminates the need for external RC networks or timing capacitors, reducing bill-of-materials count and improving reliability. A minimum 0.03µF bypass capacitor (CL) on the SHUNT pin is required for stability, but it does not affect reset timing.

How does the active-high RESET output of MAX6331LUR-T interface with common microprocessors?

The active-high RESET output of MAX6331LUR-T directly drives standard µP reset inputs designed for high-active assertion, such as those found in many ARM Cortex-M and Renesas RL78 devices. It sources up to 800µA at VOH ≥ 0.8 × V_SHUNT and sinks up to 1.2mA at VOL ≤ 0.4V. No external pull-up is needed, simplifying interface design. For µPs with bidirectional reset pins (e.g., legacy Motorola 68HC11), a 4.7kΩ series resistor is recommended to prevent contention.

What is the minimum and maximum shunt current range supported by MAX6331LUR-T?

MAX6331LUR-T operates over a shunt current range of 100µA (minimum) to 50mA (maximum). At 100µA, the device maintains regulation and valid reset functionality down to V_SHUNT = 1.2V. At 50mA, thermal derating applies: total power dissipation must stay within 320mW (SOT23-3), requiring attention to junction temperature limits. This wide range supports both ultra-low-power sleep modes and higher-current operational states in the same design.

Is MAX6331LUR-T RoHS-compliant and what packaging option does the "-T" suffix indicate?

Yes, MAX6331LUR-T is RoHS-compliant. The "-T" suffix indicates tape-and-reel packaging with lead-free (Pb-free) terminations per JEDEC J-STD-020. Analog Devices specifies lead-free compliance by replacing "-T" with "+T" in ordering codes, but the "-T" variant itself meets RoHS Directive 2011/65/EU requirements. The device uses a standard SOT23-3 package (outline U3+1) with matte tin plating and is qualified for reflow soldering per IPC/JEDEC J-STD-020.