Analog Devices Inc./Maxim Integrated MAX6314US31D3+T

Overview

MAX6314US31D3+T from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit designed to monitor VCC supply voltage and assert a bidirectional reset signal for µPs with bidirectional reset I/Os (e.g., 68HC11). It features a factory-trimmed 3.08V reset threshold, 140ms minimum reset timeout period, ±1.8% threshold accuracy at +25°C, 5µA supply current, and SOT143 package. It is used in portable/battery-powered equipment requiring reliable power-on reset and brownout detection.

For engineers reviewing the MAX6314US31D3+T datasheet, MAX6314US31D3+T pinout, MAX6314US31D3+T application, or MAX6314US31D3+T equivalent, key selection criteria include bidirectional RESET compatibility, precise 3.08V VTH tolerance over temperature, 140ms reset hold time, immunity to short VCC transients, and absence of external components for manual reset debounce.

Technical Context

The MAX6314US31D3+T implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set its 3.08V reset threshold, and an internal timer that guarantees RESET remains asserted for ≥140ms after VCC rises above threshold or MR deasserts. Its RESET output combines a 4.7kΩ pull-up resistor with a p-channel active pullup transistor, enabling fast rise times (<350ns typical) on capacitive reset buses - critical for multi-device systems using 68HC11-class µPs.

It integrates a 63kΩ internal pull-up on MR, allowing direct connection of a momentary switch to GND without external components. The device operates across -40°C to +85°C, maintains ±2.5% reset threshold accuracy over temperature, and draws only 5µA typical ICC - making it suitable for always-on battery monitoring in portable instrumentation and controllers.

Key Specifications

Pinout & Package

SOT143 (4-pin, surface-mount) package with 1.3mm × 2.9mm footprint and 0.95mm height - optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6314US31D3+T, MAX6315US31D3+T omits the bidirectional interface but simplifies design for open-drain systems, while TPS3808G31DBVR offers lower current and smaller package but requires external components and cannot support µPs needing active pullup for reset-source arbitration.

Availability

MAX6314US31D3+T is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC controllers, handheld test equipment, smart energy meters, and battery-powered instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for MAX6314US31D3+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 analog, mixed-signal, and power-management ICs for industrial, communications, and consumer applications.

The MAX6314 family was designed specifically to solve bidirectional reset interface challenges in µP-based systems - delivering precision voltage monitoring, programmable timeout, and integrated active pullup in a minimal SOT143 footprint.

FAQ

What is the exact reset threshold voltage for MAX6314US31D3+T?

The MAX6314US31D3+T has a factory-trimmed nominal reset threshold voltage of 3.08V, with ±1.8% accuracy at +25°C and ±2.5% over the full -40°C to +85°C operating temperature range. This value is laser-trimmed during manufacturing and specified in the Ordering Information table under "NOMINAL VTH (V)" for the D3 variant.

Does MAX6314US31D3+T require external components for manual reset functionality?

No, MAX6314US31D3+T does not require external components for manual reset. It includes a 63kΩ internal pull-up resistor on the MR pin, allowing direct connection of a normally open momentary switch between MR and GND. External debounce circuitry is unnecessary due to built-in glitch rejection (100ns minimum pulse width required).

How does the bidirectional RESET output of MAX6314US31D3+T differ from standard open-drain supervisors?

Unlike standard open-drain reset ICs, MAX6314US31D3+T's RESET output integrates a 4.7kΩ pull-up resistor in parallel with a p-channel active pullup transistor. This allows both the µP and the MAX6314US31D3+T to drive the line low, while enabling fast, low-capacitance rise times - essential for correct reset-source arbitration in 68HC11-compatible systems.

What is the minimum reset timeout period for MAX6314US31D3+T?

The MAX6314US31D3+T has a minimum reset timeout period (tRP) of 140ms. This is the guaranteed duration RESET remains asserted after VCC rises above 3.08V or after MR is deasserted. The actual timeout may vary slightly with temperature but remains within specification across -40°C to +85°C.

Is MAX6314US31D3+T compatible with 3.3V microcontrollers?

Yes, MAX6314US31D3+T is fully compatible with 3.3V microcontrollers. Its 3.08V reset threshold provides appropriate margin above typical 3.3V rail dropout, and its RESET output operates correctly with VCC = 3.3V, sinking up to 1.2mA while maintaining VOL ≤ 0.4V - meeting standard CMOS logic level requirements.