Analog Devices Inc./Maxim Integrated MAX6718UKYHD3+

Overview

MAX6718UKYHD3+ from Maxim Integrated is a dual-voltage microprocessor supervisory IC in 5-pin SOT23 package, monitoring VCC1 (primary) and VCC2 (secondary) supplies with factory-trimmed reset thresholds of 2.125V (VTH1) and 2.125V (VTH2), 210ms minimum reset timeout, push-pull active-low RST output, and manual reset input - used to ensure reliable power-on reset and brownout recovery in battery-powered embedded systems.

For engineers reviewing the MAX6718UKYHD3+ datasheet, MAX6718UKYHD3+ pinout, MAX6718UKYHD3+ application, or MAX6718UKYHD3+ equivalent, key selection criteria include guaranteed reset validity down to VCC1/VCC2 = 0.8V, 14µA typical supply current at 3.6V, immunity to short VCC transients, and compatibility with multivoltage systems requiring tight threshold accuracy and minimal board space.

Technical Context

The MAX6718UKYHD3+ integrates dual independent voltage comparators with ±1.5% threshold accuracy over temperature, a programmable reset timeout timer (210ms min), and internal 50kΩ MR pullup - all operating across -40°C to +85°C. It asserts RST low when either VCC1 or VCC2 falls below its respective factory-set threshold and holds reset for the full timeout after both supplies recover.

No watchdog, RSTIN, PFI, or PFO functions are included; this variant supports only dual-supply monitoring with push-pull RST and MR inputs. Its BiCMOS process ensures low leakage (<25nA on MR) and stable operation under fast VCC transients, validated by 20µs VCC-to-RST delay and 100ns MR glitch rejection.

Key Specifications

Pinout & Package

MAX6718UKYHD3+ uses a 5-pin SOT23-5 package (2.9mm × 1.6mm × 1.1mm), surface-mount, lead-free, RoHS-compliant. Pin 1 is marked with dot; pin numbering follows standard SOT23 convention (counterclockwise from mark).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G18DBVR and ADM6718AKSZ-REEL7, the MAX6718UKYHD3+ provides dedicated dual-rail supervision without watchdog overhead or external component dependencies, making it optimal for cost-sensitive, space-constrained designs where only voltage monitoring - not processor activity tracking - is needed.

Availability

MAX6718UKYHD3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, and wireless edge gateways requiring stable component supply, long-term lifecycle support, and guaranteed performance across -40°C to +85°C.

Supply support for MAX6718UKYHD3+ 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 MAX6715–MAX6729 family delivers ultra-low-voltage, small-footprint supervisory circuits optimized for multivoltage embedded systems where reliability, precision threshold matching, and minimal quiescent current are critical.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6718UKYHD3+?

The MAX6718UKYHD3+ features factory-trimmed reset thresholds of 2.125V (typical) for both VCC1 and VCC2, with ±1.5% accuracy over the full -40°C to +85°C temperature range. This is confirmed by the 'Y' suffix in the part number per Maxim's Reset Voltage Threshold Suffix Guide, corresponding to 2.125V falling threshold for both inputs. The MAX6718UKYHD3+ does not support adjustable thresholds or third-supply monitoring.

Does the MAX6718UKYHD3+ include a watchdog timer function?

No, the MAX6718UKYHD3+ does not include a watchdog timer. Per Maxim's Selector Guide, only MAX6721–MAX6729 variants support WDI input; the MAX6718UKYHD3+ is a dual-supply-only device with RST and MR pins only. Its functional block diagram and pin description confirm absence of WDI, RSTIN, PFI, or PFO terminals - making it distinct from watchdog-capable members of the same family.

What is the reset timeout period of the MAX6718UKYHD3+, and is it adjustable?

The MAX6718UKYHD3+ 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-programmed and not user-adjustable via external components or configuration pins. The timeout begins when VCC1 and VCC2 rise above their respective 2.125V thresholds and guarantees RST remains asserted for ≥210ms to satisfy µP power-up timing requirements.

Can the MAX6718UKYHD3+ operate with VCC1 = 1.8V and VCC2 = 1.2V simultaneously?

Yes, the MAX6718UKYHD3+ supports VCC1 as low as 1.8V and VCC2 as low as 0.9V, so operation at VCC1 = 1.8V and VCC2 = 1.2V is fully within specification. Its internal circuitry remains functional and reset assertion is guaranteed even if either supply drops to 0.8V. Electrical characteristics tables confirm valid operation across this range, with supply current scaling predictably (e.g., ~10µA total at 1.8V/1.2V per typical curves).

Is the RST output of the MAX6718UKYHD3+ push-pull or open-drain, and what are its drive capabilities?

The MAX6718UKYHD3+ features a push-pull active-low RST output, as confirmed by its 'U' prefix (SOT23-5) and 'K' suffix (push-pull option) in Maxim's ordering guide. It drives low to ≤0.4V at 3.2mA sink load and high to ≥0.8×VCC1 at 800µA source load - eliminating need for external pullup resistors. This differs from open-drain variants like MAX6717UKYHD3+, which require external pullups.