Analog Devices Inc./Maxim Integrated MAX6316LUK45CX+

Overview

MAX6316LUK45CX+ from Maxim Integrated is an active-low, open-drain µP supervisory circuit with watchdog and manual reset functions, designed to monitor VCC supply integrity and microprocessor activity in embedded systems. It features a factory-trimmed 4.5V reset threshold (±2.5%), 140ms minimum reset timeout, 25.6s typical watchdog timeout, and guaranteed valid reset assertion down to VCC = 1V. It is used in battery-powered controllers where brownout immunity and system-level fault recovery are critical.

For engineers reviewing the MAX6316LUK45CX+ datasheet, MAX6316LUK45CX+ pinout, MAX6316LUK45CX+ application, or MAX6316LUK45CX+ equivalent, key selection criteria include open-drain reset compatibility with multi-supply systems, immunity to sub-4µs VCC transients, 100nA typical supply current at 3.3V, and support for bidirectional reset bus timing on fast µPs like the Motorola 68HC11.

Technical Context

The MAX6316LUK45CX+ implements a precision voltage comparator with 40ppm/°C temperature coefficient to detect VCC falling below 4.5V, triggering an open-drain RESET assertion. Its watchdog timer clears on any WDI edge (rising or falling) and times out after 25.6s if unserviced - a feature enabled by internal logic that monitors WDI transitions without external clocking.

Reset remains asserted for 140ms after VCC rises above threshold or MR releases, and the device guarantees VOL ≤ 0.4V at ISINK = 3.2mA (VCC ≥ 4.5V). Its open-drain output allows connection to pullup voltages up to 6V, enabling interoperability across mixed-voltage domains such as 3.3V µP cores with 5V I/O rails.

Key Specifications

Pinout & Package

MAX6316LUK45CX+ is housed in a 5-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free (indicated by '+' suffix), rated for -40°C to +125°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6316LUK45CX+, MAX6320PUK46CY+ offers marginally higher reset threshold for tighter 5V regulation compliance, while TPS3808G33DBVR trades watchdog capability and flexibility for lower BOM count in basic reset-only designs - neither is pin-compatible, requiring layout revision.

Availability

MAX6316LUK45CX+ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6316LUK45CX+ 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 high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6316–MAX6322 family was designed specifically for robust µP supervision in harsh environments - delivering precise voltage monitoring, glitch-immune reset generation, and configurable watchdog timing in miniature SOT23 packages.

FAQ

What is the exact reset threshold voltage of MAX6316LUK45CX+ and how tightly is it specified?

The MAX6316LUK45CX+ has a factory-trimmed nominal reset threshold of 4.5V, with guaranteed tolerance of ±2.5% over the full -40°C to +125°C temperature range. This means VRST is specified between 4.388V and 4.613V at TA = +25°C, and between 4.388V × 0.975 = 4.278V and 4.613V × 1.025 = 4.728V across temperature extremes. The MAX6316LUK45CX+ achieves this via laser-trimmed internal resistors, eliminating external calibration components.

Does MAX6316LUK45CX+ support manual reset functionality, and how is it implemented?

Yes, MAX6316LUK45CX+ includes a dedicated MR (manual reset) input. Pulling MR low forces an immediate reset assertion for the full 140ms timeout period, regardless of VCC level. The pin features an internal 52kΩ pullup to VCC, so it may be left unconnected when unused. MR accepts TTL-logic levels in 5V systems and CMOS levels in 3V systems, and rejects transients shorter than 100ns - ensuring noise immunity in real-world layouts.

What is the watchdog timeout period of MAX6316LUK45CX+, and how is it triggered?

The MAX6316LUK45CX+ features a 25.6s typical watchdog timeout period (suffix 'Z'). It triggers a reset if the WDI input remains static - either continuously high or continuously low - for longer than this interval. The timer clears on any edge (rising or falling) at WDI, making it compatible with simple GPIO toggling. Leaving WDI unconnected disables the watchdog function entirely, as the internal counter services itself every 7/8 of the timeout period.

Can MAX6316LUK45CX+ operate reliably during severe VCC brownout conditions?

Yes, MAX6316LUK45CX+ guarantees valid reset assertion down to VCC = 1.0V, and its internal circuitry remains fully functional throughout this range. The open-drain RESET output maintains VOL ≤ 0.4V at ISINK = 3.2mA even at VCC = 4.5V, and the device ignores fast negative transients - e.g., a 100mV dip lasting less than 4µs will not cause spurious reset. This makes MAX6316LUK45CX+ suitable for cold-crank and battery-depletion scenarios.

What package type and environmental rating does MAX6316LUK45CX+ use?

MAX6316LUK45CX+ is supplied in a RoHS-compliant, lead-free 5-pin SOT23 package (2.9mm × 1.6mm footprint), with top-mark code 'ACDL'. It is rated for operation from -40°C to +125°C ambient temperature and qualified for industrial and automotive applications. The '+' suffix explicitly denotes lead-free construction per JEDEC J-STD-609, and the device meets MSL-1 moisture sensitivity requirements.