Analog Devices Inc./Maxim Integrated MAX6718UKTGD3

Overview

The MAX6718UKTGD3 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 1.62V (VTH1) and 0.788V (VTH2), 210ms minimum reset timeout, and guaranteed reset validity down to VCC ≥ 0.8V - used in battery-powered IoT nodes for reliable power-up sequencing and brownout detection.

For engineers reviewing the MAX6718UKTGD3 datasheet, MAX6718UKTGD3 pinout, MAX6718UKTGD3 application, or MAX6718UKTGD3 equivalent, key selection criteria include dual-supply threshold accuracy, low 14µA typical supply current at 3.6V, push-pull active-low RST output referenced to VCC1, and immunity to sub-20µs VCC transients - critical for portable medical sensors and industrial edge controllers.

Technical Context

The MAX6718UKTGD3 implements two independent voltage comparators with internal hysteresis (0.5% of VTH), each feeding a shared reset timer with 210ms min timeout (D3 suffix). It guarantees correct reset logic state when either VCC1 or VCC2 remains ≥ 0.8V, enabling operation during deep brownout conditions common in Li-ion battery discharge profiles.

No watchdog, manual-reset, or RSTIN/PFI inputs are enabled on this variant - confirmed by its part number suffix "UKTG" (5-pin SOT23, no WDI/MR/RSTIN/PFI) and pinout: pins 1=RST, 2=GND, 3=MR (internally pulled up but unused per configuration), 4=VCC2, 5=VCC1. Reset assertion occurs only on VCC1/VCC2 undervoltage events.

Key Specifications

Pinout & Package

MAX6718UKTGD3 uses a 5-pin SOT23 package (2.9mm × 1.6mm × 1.1mm height) with gull-wing leads, RoHS-compliant and tape-and-reel packaged (T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G16DBVR and ADM6712S26ARTZ-R7, the MAX6718UKTGD3 uniquely provides matched low-voltage thresholds (1.62V/0.788V) optimized for modern mixed-voltage SoCs, while maintaining 210ms timeout and 14µA ICC - making it the only option for reliable supervision of 1.8V/0.9V rails in space-constrained portable equipment.

Availability

MAX6718UKTGD3 is available at Aetrix Electronics and suitable for battery-powered wearables, industrial PLC I/O modules, automotive body control units, and medical infusion pumps requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6718UKTGD3 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 interface applications in industrial, automotive, and communications markets.

The MAX6715A–MAX6729A family delivers ultra-low-voltage dual/triple supervisory circuits targeting space-constrained, battery-operated systems requiring high-accuracy power-rail monitoring and robust reset timing - especially where VCC can decay below 1.0V.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6718UKTGD3?

The MAX6718UKTGD3 has a factory-trimmed VCC1 reset threshold of 1.62V (minimum), 1.665V (typical), and 1.71V (maximum) - specified for falling VCC1. This threshold is laser-trimmed during production and applies directly to 1.8V I/O supply monitoring without external components. The MAX6718UKTGD3 datasheet confirms this value in the Electrical Characteristics table under "VCC1 Reset Threshold (VTH1)" with suffix "W".

Does the MAX6718UKTGD3 support manual reset functionality?

The MAX6718UKTGD3 includes an MR pin (pin 3) with internal 50kΩ pullup to VCC1, but this function is disabled by default configuration - the part number suffix "UKTG" indicates no manual-reset activation. Pulling MR low will assert reset, but the device is intended for automatic-only supervision. For designs requiring active manual reset, consider MAX6715AUTLD3-T instead. The MAX6718UKTGD3 operates correctly with MR left unconnected.

What is the reset timeout period of the MAX6718UKTGD3 and how is it set?

The MAX6718UKTGD3 has a minimum reset timeout period of 140ms, typical 210ms, and maximum 280ms - set by the "D3" suffix in the part number. This timeout is internally generated by a precision RC timer and is guaranteed over -40°C to +125°C. It ensures the reset signal remains asserted long enough for microcontrollers to complete power-on initialization, and restarts if VCC1 or VCC2 falls below threshold before timeout completion. The MAX6718UKTGD3 does not require external capacitors to set this delay.

Can the MAX6718UKTGD3 monitor a 0.9V core supply reliably?

Yes, the MAX6718UKTGD3 monitors VCC2 with a factory-trimmed threshold of 0.765V (min) to 0.810V (max), centered at 0.788V - specifically designed for 0.9V core rails with 112mV headroom. Its guaranteed operation down to VCC2 = 0.8V ensures valid reset assertion even as the 0.9V rail decays during battery discharge. The MAX6718UKTGD3 achieves this with matched comparator offsets and low-input-bias-current design, validated across temperature.

Is the MAX6718UKTGD3 compatible with push-pull or open-drain reset interfaces?

MAX6718UKTGD3 features a push-pull active-low RST output (pin 1) referenced to VCC1 - it actively drives low during reset and high when deasserted, eliminating the need for an external pullup resistor. This simplifies PCB layout and improves noise immunity compared to open-drain alternatives. The MAX6718UKTGD3 output can directly drive standard CMOS reset inputs without level-shifting, supporting VCC1 from 0.8V to 5.5V.