Analog Devices Inc./Maxim Integrated MAX6314US31D2

Overview

MAX6314US31D2 from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit designed to monitor V_CC supply voltage and assert a bidirectional reset signal for µPs with compatible reset I/Os (e.g., Motorola 68HC11). It features a factory-trimmed 3.08V reset threshold, 20ms minimum reset timeout period, ±2.5% threshold accuracy over temperature, 5µA supply current, and SOT143 package. Used in portable/battery-powered equipment requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6314US31D2 datasheet, MAX6314US31D2 pinout, MAX6314US31D2 application, or MAX6314US31D2 equivalent, key selection criteria include bidirectional RESET interface capability, precise 3.08V threshold tolerance across -40°C to +85°C, guaranteed reset assertion down to V_CC = 1V, immunity to short V_CC transients, and compatibility with systems requiring manual reset debouncing without external components.

Technical Context

The MAX6314US31D2 implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set its 3.08V nominal reset threshold, with ±2.5% variation over full industrial temperature range. Its reset generator includes an internally programmed 20ms (minimum) timeout timer that holds RESET low after V_CC recovery or MR deassertion.

The RESET output combines a 4.7kΩ passive pullup resistor in parallel with a P-channel active pullup transistor and N-channel pulldown, enabling direct connection to bidirectional µP reset pins. This architecture ensures fast rising edge (≤35ns typical V_CC-to-RESET delay) even under high capacitive load conditions, solving timing violations in multi-device reset buses.

Key Specifications

Pinout & Package

SOT143 package: 4-pin, single-row, gull-wing leaded or lead-free option; 1.3mm × 2.9mm body, 0.95mm height, 0.95mm pitch; rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6314US31D2, MAX6315US31D2 requires external pullup and cannot support µP-originated reset detection, while TPS3808G31DBVR offers lower current but sacrifices bidirectional interface and MR noise immunity-making MAX6314US31D2 uniquely suited for legacy 68HC11 and similar bidirectional reset architectures.

Availability

MAX6314US31D2 is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC controllers, smart energy meters, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6314US31D2 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, computing, and consumer applications.

The MAX6314 family was designed specifically for microprocessor supervisory functions in resource-constrained systems, emphasizing precision voltage monitoring, bidirectional reset compatibility, and ultra-low quiescent current in minimal-footprint packages.

FAQ

What is the exact reset threshold voltage and tolerance for MAX6314US31D2?

The MAX6314US31D2 has a factory-trimmed nominal reset threshold of 3.08V, with ±2.5% accuracy over the full operating temperature range of -40°C to +85°C. This specification is confirmed in the Electrical Characteristics table under "Reset Threshold (Note 1)" and applies directly to the MAX6314US31D2 variant, which corresponds to the "US31" ordering suffix indicating 3.08V threshold and "D2" indicating 20ms timeout.

Does MAX6314US31D2 support bidirectional reset communication with microcontrollers like the 68HC11?

Yes, the MAX6314US31D2's RESET output integrates a 4.7kΩ pullup resistor in parallel with a P-channel active pullup transistor and N-channel pulldown, enabling true bidirectional reset signaling. This architecture allows µPs such as the Motorola 68HC11 to assert RESET themselves and detect whether the reset originated externally (supervisor) or internally (watchdog/fault), as detailed in the "Reset Output" section of the datasheet.

What is the minimum reset timeout period specified for MAX6314US31D2?

The MAX6314US31D2 is configured with a minimum reset timeout period of 20ms, as indicated by the "D2" suffix in its part number. This value is guaranteed across temperature and supply voltage variations and ensures sufficient hold time for microcontroller initialization routines, particularly in systems with slower clock startup or flash memory configuration sequences.

Can MAX6314US31D2 operate reliably down to very low V_CC levels?

Yes, the MAX6314US31D2 guarantees RESET assertion (logic low) for V_CC > 1.0V and transitions to high-impedance (open-circuit) only when V_CC falls below 1.0V. This behavior ensures robust reset signaling during brownout conditions common in battery-powered systems, and is explicitly documented in the Electrical Characteristics table under "RESET Output Voltage" and "V_CC Operating Voltage Range".

Is manual reset debouncing handled internally in MAX6314US31D2?

Yes, the MAX6314US31D2 includes internal debouncing for the MR (manual reset) input. The datasheet specifies a 100ns MR glitch rejection time and a 1µs minimum MR input pulse width, confirming that transient noise on the MR line is filtered without requiring external RC networks. Additionally, MR features a 63kΩ internal pullup resistor, allowing direct connection of a momentary switch to GND.