Analog Devices Inc./Maxim Integrated MAX6316MUK46CY+

Overview

MAX6316MUK46CY+ from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with active-low bidirectional reset output, 4.63V factory-trimmed reset threshold, 140ms minimum reset timeout, and 1.6s typical watchdog timeout. It monitors VCC supply integrity and µP activity in embedded systems, ensuring reliable power-on, brownout, and watchdog-triggered resets for Motorola 68HC11-compatible controllers.

For engineers reviewing the MAX6316MUK46CY+ datasheet, MAX6316MUK46CY+ pinout, MAX6316MUK46CY+ application, or MAX6316MUK46CY+ equivalent, key selection criteria include bidirectional reset compatibility with µP reset I/O, guaranteed reset validity down to VCC = 1V, immunity to sub-4µs negative VCC transients, and integrated 4.7kΩ pullup + active P-channel pullup for fast low-to-high RESET transitions under capacitive load.

Technical Context

The MAX6316MUK46CY+ implements a bidirectional reset architecture optimized for µPs like the Motorola 68HC11 that distinguish external vs. internal reset sources by sampling RESET state after two clock cycles. Its internal 4.7kΩ resistor and active P-channel pullup (enabled above 0.65V and 0.85×VCC) ensure RESET rises to 0.8×VCC within required timing windows even with ≥120pF total line capacitance.

It features a factory-laser-trimmed voltage divider setting VRST = 4.63V ±2.5%, a watchdog timer cleared on WDI edge transitions (min pulse width 50ns), and MR input with 52kΩ internal pullup and 100ns glitch rejection. Reset assertion occurs on VCC < VRST, MR low, or WDI stall beyond 1.6s.

Key Specifications

Pinout & Package

MAX6316MUK46CY+ is housed in a 5-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), RoHS-compliant and lead-free (indicated by '+' suffix). The compact footprint supports high-density PCB layouts in space-constrained portable and industrial applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6316LUK46CY+, the MAX6316MUK46CY+ adds bidirectional reset capability essential for 68HC11-class diagnostics, while TPS3808G33DBVR offers lower quiescent current but sacrifices both watchdog and programmable threshold-making it suitable only for fixed-voltage, non-diagnostic applications.

Availability

MAX6316MUK46CY+ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, and portable test equipment requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6316MUK46CY+ 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 medical applications.

The MAX6316–MAX6322 family was engineered specifically for µP reset supervision in harsh environments, emphasizing VCC transient immunity, wide temperature operation (-40°C to +125°C), and flexible reset output configurations including bidirectional variants.

FAQ

What is the exact reset threshold voltage of the MAX6316MUK46CY+ and how tightly is it specified?

The MAX6316MUK46CY+ has a factory-trimmed nominal reset threshold of 4.63V, with a guaranteed tolerance of ±2.5% over the full operating temperature range of -40°C to +125°C. This specification ensures precise brownout detection for 5V systems without requiring external calibration or trimming components, and is laser-trimmed during manufacturing using Maxim's proprietary process.

Does the MAX6316MUK46CY+ support bidirectional reset functionality, and what µP families is it compatible with?

Yes, the MAX6316MUK46CY+ features a true bidirectional active-low reset output explicitly designed for µPs with bidirectional reset I/O, such as the Motorola 68HC11. Its integrated 4.7kΩ pullup resistor and active P-channel FET enable fast low-to-high transitions even under 200pF capacitive loading, allowing the µP to determine reset source (external supervisor vs. internal fault) by sampling RESET state after two clock cycles.

What is the watchdog timeout period of the MAX6316MUK46CY+, and how is it triggered?

The MAX6316MUK46CY+ has a typical watchdog timeout period of 1.6 seconds. It is triggered when the WDI input remains static (neither rising nor falling edge) for longer than this period. The internal watchdog timer clears on any WDI edge transition (minimum pulse width 50ns) or during reset assertion, and restarts counting once reset deasserts - providing robust software execution monitoring for embedded firmware loops.

Can the MAX6316MUK46CY+ operate reliably during severe VCC supply transients, and what is its immunity specification?

Yes, the MAX6316MUK46CY+ is specifically designed to ignore fast negative VCC transients. It is immune to transients ≤4µs in duration when the voltage dip is ≤100mV below the 4.63V reset threshold. This immunity is verified across temperature and ensures no false resets occur during common switching noise events, such as those seen in automotive load-dump or industrial relay-coil flyback scenarios.

What is the minimum supply voltage at which the MAX6316MUK46CY+ guarantees valid reset output levels?

The MAX6316MUK46CY+ guarantees valid reset output logic levels down to VCC = 1.0V. Specifically, the RESET output remains a valid logic low (≤0.4V) when sinking 3.2mA and a valid logic high (≥0.8×VCC) when sourcing 800µA, even at this ultra-low supply voltage. This ensures deterministic reset behavior during deep brownout conditions prior to complete power collapse.