Analog Devices Inc./Maxim Integrated MAX6314US44D4-T

Overview

MAX6314US44D4-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., Motorola 68HC11). It features a factory-trimmed 4.39V reset threshold, 1120ms 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 protection.

For engineers reviewing the MAX6314US44D4-T datasheet, MAX6314US44D4-T pinout, MAX6314US44D4-T application, or MAX6314US44D4-T equivalent, key selection criteria include bidirectional RESET compatibility, precise 4.39V threshold, long 1120ms timeout for system stabilization, immunity to short VCC transients, and elimination of external pull-up components.

Technical Context

The MAX6314US44D4-T implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set its 4.39V reset threshold, and an internal timer that guarantees RESET remains asserted for ≥1120ms after VCC rises above threshold or manual reset deassertion. Its bidirectional RESET output combines a 4.7kΩ passive pull-up resistor with a p-channel active pull-up transistor enabled for 2µs upon rising-edge detection, enabling fast rise time even under high capacitive load.

This architecture directly supports µP reset protocols requiring low-to-high transition recognition within tight timing windows (e.g., two E-clock cycles on 68HC11), while maintaining compatibility with open-drain-style external assertion by other devices on the shared reset bus.

Key Specifications

Pinout & Package

SOT143 package: 4-pin, surface-mount, lead-free compatible, -40°C to +85°C operating temperature range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6314US44D4-T, MAX6315US44D4-T removes the internal pull-up and active pull-up transistor-making it unsuitable for 68HC11-style bidirectional detection-but retains identical threshold and timeout for simpler open-drain designs. TPS3808G33DBVR offers higher accuracy and adjustable timeout but sacrifices manual reset, bidirectional capability, and exact 4.39V threshold matching.

Availability

MAX6314US44D4-T is available at Aetrix Electronics and suitable for portable instrumentation, industrial controllers, medical handsets, and automotive body electronics requiring stable component supply and long-term lifecycle support.

Supply support for MAX6314US44D4-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) designs precision analog and mixed-signal ICs for power, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX6314 family delivers highly accurate, low-power µP supervisory circuits optimized for systems requiring bidirectional reset compatibility, factory-trimmed thresholds, and minimal external components.

FAQ

What is the reset threshold voltage of the MAX6314US44D4-T?

The MAX6314US44D4-T has a factory-trimmed nominal reset threshold voltage of 4.39V, with ±1.8% accuracy at +25°C and ±2.5% over the full -40°C to +85°C temperature range. This precise threshold ensures reliable detection of VCC drops in systems powered near 4.4V, such as certain industrial controllers and portable instruments using regulated 4.5V supplies. The value is laser-trimmed and does not require external calibration.

Does the MAX6314US44D4-T support bidirectional reset communication with microcontrollers?

Yes, the MAX6314US44D4-T supports bidirectional reset communication via its specialized RESET output, which integrates a 4.7kΩ pull-up resistor and a p-channel active pull-up transistor. This design enables direct interface with µPs like the Motorola 68HC11 that use bidirectional reset I/O pins to distinguish between internal and external reset sources. The active pull-up ensures RESET transitions from low to high within strict timing windows-even under capacitive loads-without requiring external components.

What is the reset timeout period for the MAX6314US44D4-T?

The MAX6314US44D4-T provides a minimum reset timeout period of 1120ms. This duration begins when VCC rises above the 4.39V threshold or when the manual reset (MR) input is deasserted, and guarantees RESET remains asserted for at least this interval to allow complete power rail stabilization and peripheral initialization. The timeout is internally programmed and fixed for this variant-no external capacitor or resistor adjustment is needed.

Can the MAX6314US44D4-T operate with supply voltages below 2.5V?

Yes, the MAX6314US44D4-T operates over a VCC range of 1.0V to 5.5V. While its reset function activates only when VCC falls below the 4.39V threshold, the device continues to draw only 5µA typical supply current down to 1.0V and maintains valid RESET output behavior (logic low assertion) across this full range. Below 1.0V, RESET becomes high-impedance, consistent with its specified absolute minimum rating.

Is there a manual reset input on the MAX6314US44D4-T, and how is it implemented?

Yes, the MAX6314US44D4-T includes a dedicated manual reset (MR) input on pin 3. MR is active-low with an internal 63kΩ pull-up resistor, allowing it to be left unconnected if unused. When pulled low (e.g., via a momentary switch to GND), MR immediately asserts RESET and holds it active for the full 1120ms timeout period after MR returns high. No external debounce circuitry is required due to built-in noise immunity and glitch rejection.