Analog Devices Inc./Maxim Integrated MAX6314US26D2

Overview

MAX6314US26D2 from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit designed to monitor V_CC and assert a bidirectional reset signal for µPs like the 68HC11. It features a factory-trimmed 2.63V reset threshold, 20ms minimum reset timeout period, ±2.5% threshold accuracy over temperature, 5µA supply current, and SOT143 package - enabling reliable power-up/brownout detection in portable and industrial control systems.

For engineers reviewing the MAX6314US26D2 datasheet, MAX6314US26D2 pinout, MAX6314US26D2 application, or MAX6314US26D2 equivalent, key selection criteria include its bidirectional RESET output architecture, precise 2.63V threshold with 20ms timeout, immunity to short V_CC transients, and compatibility with µPs requiring active pullup-assisted reset line timing.

Technical Context

The MAX6314US26D2 implements a voltage-monitoring comparator with laser-trimmed internal resistive divider to detect V_CC falling below 2.63V (±2.5% over –40°C to +85°C), triggering a reset assertion that persists for ≥20ms after V_CC recovers. Its RESET output combines a 4.7kΩ passive pullup with a p-channel active pullup transistor enabled for 2µs upon rising-edge detection, ensuring fast rise time (<350ns at C_L = 100pF) even with multiple devices on the bus.

It integrates a manual reset input (MR) with 63kΩ internal pullup, glitch rejection of ≤100ns, and MR-to-RESET delay of ≤500ns. The device operates across V_CC = 1.0V to 5.5V and draws only 5µA typical supply current at +25°C - making it suitable for battery-powered systems where quiescent power and noise immunity are critical.

Key Specifications

Pinout & Package

SOT143 package: 4-pin, surface-mount, lead-free or leaded options available; dimensions per Maxim package outline SOT143.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6314US26D2, MAX6315US26D2-T lacks active pullup and thus cannot replace it in bidirectional reset systems, while TPS3808G26DBVR offers tighter threshold tolerance but abandons the core arbitration functionality essential for 68HC11-class µPs.

Availability

MAX6314US26D2 is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, automotive body electronics, smart energy meters, and battery-powered instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for MAX6314US26D2 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, mixed-signal, and power-management ICs for demanding industrial, automotive, and computing applications.

The MAX6314 product line delivers highly accurate, low-power µP supervisory circuits optimized for systems requiring deterministic reset behavior, bidirectional reset arbitration, and robust transient immunity - especially in portable and harsh-environment deployments.

FAQ

What is the exact reset threshold voltage and tolerance for MAX6314US26D2?

The MAX6314US26D2 has a nominal reset threshold of 2.63V, with ±2.5% accuracy over the full operating temperature range of –40°C to +85°C. This value is factory-laser-trimmed and specified in the Electrical Characteristics table under "Reset Threshold (Note 1)" with V_TH = 2.63V, min = V_TH – 2.5%, max = V_TH + 2.5%. The MAX6314US26D2 maintains this precision without external calibration or trimming components.

Does MAX6314US26D2 support bidirectional reset communication with the 68HC11 µP?

Yes, the MAX6314US26D2 is explicitly designed for bidirectional reset compatibility with the Motorola 68HC11 and other µPs featuring bidirectional reset I/O pins. Its RESET output integrates both a 4.7kΩ passive pullup and a p-channel active pullup transistor, enabling the µP to drive the line low and the supervisor to drive it high - a requirement for reset-source arbitration in the 68HC11's boot sequence. This functionality is confirmed in the Functional Diagram, Typical Operating Circuit, and Detailed Description sections of the MAX6314US26D2 datasheet.

What is the minimum reset timeout period for MAX6314US26D2, and how is it guaranteed?

The MAX6314US26D2 provides a minimum reset timeout period of 20ms, as indicated by the "D2" suffix in its part number and confirmed in the Ordering Information table. This value is internally programmed and guaranteed over temperature and voltage - the Electrical Characteristics table specifies t_RP = 20ms (min) for the D2 variant, with typical values up to 28ms and maximum 40ms at +25°C. The timeout begins when V_CC rises above 2.63V or when MR is deasserted, and RESET remains low for the full interval before releasing.

Can MAX6314US26D2 operate down to 1.0V supply voltage?

Yes, the MAX6314US26D2 is fully specified to operate across V_CC = 1.0V to 5.5V, as stated in the Absolute Maximum Ratings and Electrical Characteristics tables. At V_CC ≥ 1.0V, the RESET output is guaranteed to sink current and remain a valid logic low; below 1.0V, RESET becomes high-impedance. This extended low-voltage operation makes the MAX6314US26D2 suitable for end-of-life battery monitoring in single-cell systems - a key design feature validated in the Supply Current vs. Supply Voltage graph (Figure MAX6314-03).

Is an external pullup resistor required for the RESET pin of MAX6314US26D2?

No external pullup resistor is required for the RESET pin of MAX6314US26D2. The device integrates both a 4.7kΩ passive pullup resistor and a p-channel active pullup transistor in parallel - as documented in the Pin Description, Functional Diagram, and Detailed Description sections. This dual-path pullup eliminates the need for external components while ensuring fast rise time (<350ns) and reliable bidirectional reset arbitration. Using an external pullup would conflict with the internal design and is not recommended.