Analog Devices Inc./Maxim Integrated MAX6316LUK31BX+

Overview

MAX6316LUK31BX+ from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with active-low push/pull reset output, manual reset input, and watchdog timer. It features a factory-trimmed 3.08V reset threshold (±1.5% at +25°C), 140ms minimum reset timeout, and 102ms typical watchdog timeout. Designed for brownout protection and system recovery in battery-powered embedded controllers.

For engineers reviewing the MAX6316LUK31BX+ datasheet, MAX6316LUK31BX+ pinout, MAX6316LUK31BX+ application, or MAX6316LUK31BX+ equivalent, key selection criteria include guaranteed reset validity down to VCC = 1V, immunity to sub-4µs negative VCC transients, bidirectional reset compatibility support, and AEC-Q100 qualification for automotive-grade reliability.

Technical Context

The MAX6316LUK31BX+ implements a precision voltage monitor using a laser-trimmed resistor divider to set its 3.08V reset threshold, with ±2.5% tolerance over –40°C to +125°C. Its reset generator asserts an active-low push/pull output for 140ms after VCC rises above threshold or MR deasserts.

Watchdog functionality clears on any WDI edge (rising or falling) with 102ms timeout; WDI input draws ≤160µA when high and is internally serviced if left unconnected. Manual reset (MR) has 52kΩ internal pullup, 100ns glitch rejection, and 230ns propagation delay at VCC = 5V.

Key Specifications

Pinout & Package

MAX6316LUK31BX+ is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2A, outline 21-0057), measuring 2.9mm × 1.6mm × 1.1mm with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6316MUK31BX+, the MAX6316LUK31BX+ offers simpler push/pull drive but lacks bidirectional bus arbitration; versus TPS3808G33DBVR, it delivers tighter threshold accuracy and MR flexibility critical for robust embedded restart logic.

Availability

MAX6316LUK31BX+ is available at Aetrix Electronics and suitable for portable computers, intelligent instruments, and embedded control systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6316LUK31BX+ 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 connectivity applications in industrial, automotive, and computing markets.

The MAX6316–MAX6322 family was engineered specifically for microprocessor supervision in space-constrained, high-reliability systems - delivering integrated reset, watchdog, and manual reset functions in miniature SOT23 packaging.

FAQ

What is the exact reset threshold voltage of MAX6316LUK31BX+ and how does it vary with temperature?

The MAX6316LUK31BX+ has a factory-trimmed nominal reset threshold of 3.08V, with ±1.5% tolerance at +25°C and ±2.5% over –40°C to +125°C. Its temperature coefficient is 40ppm/°C, meaning drift is limited to ±0.012V across the full operating range. This precision enables reliable brownout detection in 3.3V systems where marginal voltage sags must trigger reset without false positives.

Does MAX6316LUK31BX+ support manual reset, and what are the electrical requirements for the MR pin?

Yes, MAX6316LUK31BX+ includes a dedicated MR (manual reset) input with internal 52kΩ pullup to VCC. The MR pin accepts TTL-logic levels in 5V systems and CMOS levels in 3V systems. It rejects transients shorter than 100ns and requires only a 1µs minimum low pulse width. No external debouncing is needed - a simple momentary switch to ground suffices for field-service reset functionality.

How does the watchdog timer in MAX6316LUK31BX+ operate, and what is its timeout period?

The MAX6316LUK31BX+ watchdog timer has a typical timeout of 102ms (X-type variant), clearing on any rising or falling edge at the WDI pin. If WDI remains static beyond this period, RESET asserts for 140ms. When WDI is left unconnected, the timer is internally serviced at ~7/8 the timeout interval. This behavior ensures fail-safe operation even if the host MCU fails to toggle WDI.

Is MAX6316LUK31BX+ suitable for automotive applications, and what qualifications does it hold?

Yes, MAX6316LUK31BX+ is AEC-Q100 qualified for automotive use. It operates reliably from –40°C to +125°C, withstands supply transients per automotive test standards, and features guaranteed reset assertion down to VCC = 1V - essential for cold-crank scenarios. Its SOT23 package meets mechanical and thermal requirements for under-hood ECUs and body control modules.

What package type and footprint does MAX6316LUK31BX+ use, and are there layout considerations?

MAX6316LUK31BX+ uses a standard 5-pin SOT23 package (outline 21-0057, land pattern 90-0174). Key layout recommendations include placing a 0.1µF ceramic bypass capacitor between VCC and GND as close as possible to the device, routing MR and WDI with minimal trace length to reduce noise coupling, and avoiding copper pours under the package to maintain thermal performance. No external pullup is needed for RESET.