Analog Devices Inc./Maxim Integrated MAX6331TUR-T

Overview

The MAX6331TUR-T from Analog Devices is a precision shunt regulator with integrated active-high power-on reset function in a 3-pin SOT23-3 package. It delivers a regulated 3.3V shunt voltage (±1.5% tolerance), asserts RESET for 140ms after V_SHUNT exceeds 3.06V, operates across -40°C to +85°C, and supports 100µA–50mA shunt current - enabling compact, reliable µP supervision in high-voltage-powered embedded systems.

For engineers reviewing the MAX6331TUR-T datasheet, MAX6331TUR-T pinout, MAX6331TUR-T application, or MAX6331TUR-T equivalent, this device serves as a space-constrained, single-component solution for brownout detection, power-up sequencing, and voltage monitoring in microprocessor-based controllers, intelligent instruments, and portable equipment requiring stable 3.3V regulation and deterministic reset timing.

Technical Context

The MAX6331TUR-T integrates a bandgap-referenced shunt regulator and a precision reset generator with internal 140ms timeout timer. Its active-high RESET output transitions high only after V_SHUNT rises above 3.06V and remains high for ≥140ms, ensuring µP initialization completes before release. The device uses no external timing components and maintains reset assertion during brownouts via continuous threshold monitoring.

It functions as a two-terminal shunt element (SHUNT–GND) while providing a third-terminal push-pull RESET output referenced to GND. The shunt regulation and reset threshold both exhibit 40ppm/°C tempco, and the device sustains operation with input voltages up to 50V when paired with an appropriate series resistor (R_S).

Key Specifications

Pinout & Package

MAX6331TUR-T is housed in a RoHS-compliant 3-pin SOT23-3 package (package code U3+1, outline 21-0151). The device uses standard SOT23 footprint with 0.95mm pitch and 1.3mm body width.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6330TUR-T, the MAX6331TUR-T provides active-high reset compatibility with modern µPs lacking dedicated active-low inputs; compared with TLV803EB33DBZR, it eliminates the need for a separate regulator, simplifying design and improving system-level accuracy through co-located reference and reset threshold.

Availability

MAX6331TUR-T is available at Aetrix Electronics and suitable for industrial controllers, smart home appliances, and portable medical instruments requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6331TUR-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 product line delivers integrated precision shunt regulation and reset supervision in ultra-small packages, targeting space-constrained, cost-sensitive µP systems powered from high-voltage rails.

FAQ

What is the exact shunt voltage and reset threshold of the MAX6331TUR-T?

The MAX6331TUR-T provides a nominal shunt voltage of 3.3V with ±1.5% tolerance over temperature, and a reset threshold of 3.06V (also ±1.5%). These values are confirmed in the Electrical Characteristics table for the "T" suffix variant at -40°C to +85°C, and both parameters track with 40ppm/°C tempco for consistent performance across operating conditions. The MAX6331TUR-T maintains these specifications without external calibration.

How does the MAX6331TUR-T generate its 140ms reset timeout without external components?

The MAX6331TUR-T embeds a factory-trimmed RC timing circuit within its die to deliver a precise 140ms reset timeout after V_SHUNT exceeds the 3.06V threshold. This internal timer eliminates the need for external capacitors or resistors, reduces layout sensitivity, and ensures consistent timing across temperature and voltage variations. No user configuration or external parts are required to achieve the specified timeout.

Can the MAX6331TUR-T drive a microprocessor reset pin directly?

Yes, the MAX6331TUR-T's push-pull RESET output can drive most µP reset inputs directly. It sources up to 800µA and sinks up to 3.2mA, meeting standard CMOS input requirements. For µPs with bidirectional reset I/O (e.g., Motorola 68HC11), a 4.7kΩ series resistor is recommended to prevent contention - a detail explicitly documented in the Applications Information section of the MAX6331TUR-T datasheet.

What is the minimum and maximum shunt current supported by the MAX6331TUR-T?

The MAX6331TUR-T operates reliably across a shunt current range of 100µA to 50mA. Below 100µA, regulation degrades; above 50mA, thermal limits may be exceeded. This range allows flexible R_S selection for diverse input voltages (up to 50V) and load currents, and is validated across the full -40°C to +85°C temperature range per the Absolute Maximum Ratings and Electrical Characteristics tables.

Is the MAX6331TUR-T compatible with lead-free soldering processes?

Yes, the MAX6331TUR-T is offered in lead-free packaging, indicated by the "+T" suffix (e.g., MAX6331TUR+T). The standard "-T" version is leaded but RoHS-exempt; both variants support standard reflow profiles with peak temperatures up to +300°C for 10 seconds, as specified in the Absolute Maximum Ratings. Land pattern and thermal design rules follow Analog Devices' SOT23-3 outline 21-0151.