Analog Devices Inc./Maxim Integrated MAX6316MUK31CY+T

Overview

MAX6316MUK31CY+T from Maxim Integrated is a 5-pin SOT23 microprocessor supervisory circuit with bidirectional active-low reset output, 3.08V factory-trimmed reset threshold (±2.5% over -40°C to +125°C), 140ms minimum reset timeout, and 1.6s typical watchdog timeout. It monitors VCC supply integrity and provides manual reset and watchdog supervision for embedded controllers requiring robust brownout protection.

For engineers reviewing the MAX6316MUK31CY+T datasheet, MAX6316MUK31CY+T pinout, MAX6316MUK31CY+T application, or MAX6316MUK31CY+T equivalent, key selection criteria include its bidirectional reset interface for Motorola 68HC11-compatible systems, guaranteed reset validity down to VCC = 1V, immunity to sub-4µs negative VCC transients, and integrated 4.7kΩ pullup with active P-channel assist for fast RESET rise time under capacitive load.

Technical Context

The MAX6316MUK31CY+T implements a dual-stage reset generator with voltage monitoring, manual reset input (MR), and watchdog timer (WDI). Its bidirectional RESET output combines a 4.7kΩ passive pullup resistor and an active P-channel FET that engages above 0.65V to ensure RESET transitions high within two MCU clock cycles-even with >250pF bus capacitance-enabling reliable source discrimination in 68HC11-style systems.

Reset assertion occurs when VCC falls below 3.08V, MR is pulled low, or WDI remains static beyond 1.6s. The device guarantees valid logic levels on RESET down to VCC = 1V and features internal ESD protection on MR and WDI pins, with glitch rejection of 100ns pulses on MR and immunity to short negative VCC transients as brief as 200ns.

Key Specifications

Pinout & Package

MAX6316MUK31CY+T is housed in a RoHS-compliant 5-pin SOT23 package (package code U5+2A, outline 21-0057) with 0.95mm pitch and thermal resistance θJA = 255.9°C/W on multilayer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6316LUK31CY+T and TLV803EB30DBVR, MAX6316MUK31CY+T uniquely delivers bidirectional reset with active pullup for source-aware systems, integrated watchdog timing, and manual reset-making it the sole option among the three for 68HC11-compatible or multi-device reset bus architectures requiring deterministic reset cause identification.

Availability

MAX6316MUK31CY+T is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, and automotive body control modules requiring stable component supply with AEC-Q100 qualification and extended temperature support.

Supply support for MAX6316MUK31CY+T 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 industrial, automotive, and computing applications.

The MAX6316–MAX6322 family delivers compact, low-power µP supervisory circuits with configurable reset thresholds, timeout periods, and output types-including bidirectional variants optimized for legacy microcontrollers with source-discriminating reset requirements.

FAQ

What is the exact reset threshold voltage of MAX6316MUK31CY+T and how is it trimmed?

The MAX6316MUK31CY+T has a factory-trimmed nominal reset threshold of 3.08V, with tolerance of ±1.5% at +25°C and ±2.5% over -40°C to +125°C. This value is achieved using laser-trimmed internal resistors per Table 1 of the datasheet, and corresponds to the "31" suffix in the part number (3.08V = 31 × 0.1V offset from 2.5V base). No external components are needed to set this threshold.

Does MAX6316MUK31CY+T support bidirectional reset functionality, and what microcontrollers is it compatible with?

Yes, MAX6316MUK31CY+T features a true bidirectional active-low RESET output designed specifically for microcontrollers with bidirectional reset pins, such as the Motorola 68HC11. Its internal architecture includes both a 4.7kΩ pullup resistor and an active P-channel FET that engages above 0.65V to ensure fast rise time-enabling the µP to distinguish between externally and self-initiated resets based on RESET line behavior.

What are the watchdog timeout options available for MAX6316MUK31CY+T, and how is it configured?

The MAX6316MUK31CY+T is factory-configured with a typical watchdog timeout of 1.6s (Y-series), as indicated by the "Y" implied in the "UK31" ordering code per Table 3. The watchdog is edge-triggered on WDI: any rising or falling edge clears the timer. To disable it, leave WDI unconnected-the internal timer is then serviced automatically at ~7/8 of the nominal period.

Can MAX6316MUK31CY+T operate reliably during deep brownout conditions?

Yes, MAX6316MUK31CY+T guarantees valid RESET output states down to VCC = 1V, including proper logic-level assertion and deassertion. This ensures deterministic behavior during severe supply droop-critical for safe shutdown sequencing in battery-powered devices. The device remains functional and continues monitoring until VCC falls below 1.0V absolute minimum rating.

What is the MR input behavior on MAX6316MUK31CY+T, and does it require external pull-up?

The MR input on MAX6316MUK31CY+T is active-low and includes a 52kΩ internal pullup resistor to VCC, so no external component is required. A low pulse ≥1.5µs (over -40°C to +125°C) forces reset for the full 140ms timeout period. MR accepts TTL/CMOS logic levels and rejects 100ns glitches; it must be driven from the same supply as VCC to avoid violating absolute maximum ratings.