Analog Devices Inc./Maxim Integrated MAX6718UKWGD3-T

Overview

MAX6718UKWGD3-T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit in 5-pin SOT23 package, monitoring VCC1 (primary supply) and VCC2 (secondary supply) with factory-trimmed reset thresholds of 4.625V (VTH1) and 3.075V (VTH2), 210ms minimum reset timeout, push-pull active-low RST output, and guaranteed reset validity down to VCC1 or VCC2 = 0.8V - used in telecom power management and portable equipment for reliable system initialization.

For engineers reviewing the MAX6718UKWGD3-T datasheet, MAX6718UKWGD3-T pinout, MAX6718UKWGD3-T application, or MAX6718UKWGD3-T equivalent, key selection factors include dual-supply threshold accuracy (±1.5% over temperature), ultra-low 14µA typical supply current at 3.6V, immunity to sub-20µs VCC transients, and compatibility with manual reset and watchdog-free designs requiring deterministic reset timing.

Technical Context

The MAX6718UKWGD3-T implements independent voltage comparators for VCC1 and VCC2, each referenced to precision internal bandgap references, with hysteresis of 0.5% of threshold voltage to prevent chatter during slow supply ramps. Its reset logic asserts RST low when either supply falls below its trimmed threshold and holds for a fixed 210ms (min) timeout after both supplies recover.

This device uses BiCMOS process technology (1072 transistors), operates across -40°C to +85°C, and guarantees valid push-pull RST output state even as VCC1 or VCC2 drops to 0.8V - enabling robust brownout detection in battery-backed systems where supply collapse must trigger controlled shutdown before logic corruption occurs.

Key Specifications

Pinout & Package

MAX6718UKWGD3-T is housed in a 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), surface-mount, lead-free compatible. Pin 1 is marked with dot; pin order is standard SOT23 orientation (pin 1 top-left, counterclockwise).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-voltage supervisory applications.

Compared with MAX6716UTLTD3-T, MAX6718UKWGD3-T saves BOM count via integrated push-pull drive; versus TPS3808G33DBVR, it adds critical dual-supply margin control essential for mixed-voltage SoC platforms - making it optimal for telecom and industrial systems demanding coordinated rail validation.

Availability

MAX6718UKWGD3-T is available at Aetrix Electronics and suitable for telecom infrastructure, portable medical devices, and industrial PLCs requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for MAX6718UKWGD3-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 and mixed-signal ICs for power, sensing, and connectivity applications, with focus on high-reliability industrial and communications markets.

The MAX6715–MAX6729 family delivers ultra-low-voltage dual/triple supervisory circuits optimized for multirail systems where deterministic reset timing, low quiescent current, and guaranteed operation down to 0.8V are mandatory for functional safety.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6718UKWGD3-T?

The MAX6718UKWGD3-T has factory-trimmed reset thresholds of 4.625V (VTH1) for VCC1 and 3.075V (VTH2) for VCC2, with ±1.5% maximum deviation over -40°C to +85°C. These values are encoded in the "WG" suffix per Maxim's Reset Voltage Threshold Suffix Guide and verified in the Electrical Characteristics table of the official datasheet. The MAX6718UKWGD3-T does not support adjustable thresholds - both are fixed at time of manufacture.

Does the MAX6718UKWGD3-T include a watchdog timer or power-fail functionality?

No, the MAX6718UKWGD3-T does not include watchdog timer or power-fail input/output features. Per the Selector Guide, it belongs to the MAX6717/MAX6718 subgroup - dual-voltage supervisors with manual reset (MR) only. Watchdog capability appears starting with MAX6721, and power-fail (PFI/PFO) begins with MAX6728. The MAX6718UKWGD3-T provides dedicated VCC1/VCC2 monitoring, MR input, and push-pull RST output - no WDI, PFI, or PFO pins are implemented.

What is the reset timeout period of the MAX6718UKWGD3-T, and is it adjustable?

The MAX6718UKWGD3-T has a fixed minimum reset timeout period of 210ms, indicated by the "D3" suffix in its part number per Maxim's Reset Timeout Period Suffix Guide. This value is factory-set and non-adjustable - no external capacitor or resistor modifies the delay. The timeout begins when both VCC1 and VCC2 rise above their respective thresholds and ends 210ms later, ensuring sufficient hold time for processor initialization. Typical value is 210ms; min is guaranteed at 140ms, max at 280ms.

Can the MAX6718UKWGD3-T operate with VCC1 = 2.5V and VCC2 = 1.8V?

Yes, the MAX6718UKWGD3-T supports VCC1 from 1.8V to 5.0V and VCC2 from 0.9V to 3.3V per datasheet Absolute Maximum Ratings and Electrical Characteristics. However, its factory-trimmed thresholds (4.625V/3.075V) exceed those supply levels - meaning it will assert reset continuously if powered at 2.5V/1.8V. It is intended for systems where VCC1 ≥ 4.625V (e.g., 5V rail) and VCC2 ≥ 3.075V (e.g., 3.3V rail). For lower-voltage rails, select a variant with matching suffix (e.g., "SW" for 2.925V/1.710V).

Is the RST output of the MAX6718UKWGD3-T push-pull or open-drain, and what are its drive capabilities?

The MAX6718UKWGD3-T features a push-pull active-low RST output (Pin 1), as confirmed by the Selector Guide and Pin Description table. It sources up to 800µA at VCC1 ≥ 4.5V (VOH ≥ 0.8×VCC1) and sinks up to 3.2mA at VCC1 ≥ 4.5V (VOL ≤ 0.4V). This eliminates need for external pullup resistors and allows direct connection to µP reset inputs - unlike open-drain variants (e.g., MAX6717) which require external biasing. The MAX6718UKWGD3-T RST is referenced to VCC1 and fully specified from 1.0V to 5.5V supply range.