Analog Devices Inc./Maxim Integrated MAX6723UTWGD3+T

Overview

MAX6723UTWGD3+T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (4.625V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference). It asserts active-low open-drain reset for ≥210ms after any monitored supply drops below threshold or manual reset is triggered, and includes watchdog timer with 35s startup/1.12s normal timeout. Used in multivoltage telecom and industrial systems requiring reliable power-up sequencing and brownout protection.

For engineers reviewing the MAX6723UTWGD3+T datasheet, MAX6723UTWGD3+T pinout, MAX6723UTWGD3+T application, or MAX6723UTWGD3+T equivalent, key selection criteria include triple-supply monitoring capability, factory-trimmed dual thresholds, RSTIN-adjustable third voltage down to 0.62V, 210ms reset timeout, and guaranteed reset validity down to VCC1/VCC2 = 0.8V - critical for low-voltage battery-operated and embedded control designs.

Technical Context

The MAX6723UTWGD3+T implements dual independent voltage comparators for VCC1 and VCC2, plus a high-impedance RSTIN comparator referenced to a 626.5mV internal bandgap. Reset assertion is latched and held by a monostable timeout circuit with 210ms minimum duration, immune to sub-20µs VCC transients.

It features an open-drain RST output (driven by VCC1), manual reset input (MR) with 50kΩ internal pullup, and watchdog timer with dual-mode operation: 35s initial timeout after reset, then 1.12s normal timeout after first WDI edge. No power-fail (PFI/PFO) or active-high reset functions are included in this variant.

Key Specifications

Pinout & Package

MAX6723UTWGD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), surface-mount, lead-free (RoHS-compliant), with gull-wing leads and thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6724UTWGD3+T, the MAX6723UTWGD3+T provides open-drain flexibility for shared reset buses, while TPS3808G33DBVR trades triple monitoring and watchdog for 90% lower quiescent current - making MAX6723UTWGD3+T optimal for multirail systems requiring robust fault coverage and deterministic timing.

Availability

MAX6723UTWGD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, portable medical devices, and network switch designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6723UTWGD3+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed specifically for space-constrained multivoltage systems needing reliable, low-quiescent-current supervision with flexible threshold options, watchdog safety, and guaranteed operation down to 0.8V supply - targeting telecom, industrial, and portable equipment.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6723UTWGD3+T?

The MAX6723UTWGD3+T has a factory-trimmed VCC1 reset threshold of 4.625V, with a tolerance of ±125mV (min 4.500V, max 4.750V) over temperature. This value is encoded in the "W" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is verified across the -40°C to +85°C operating range. The MAX6723UTWGD3+T uses this precise threshold to supervise 5V or 4.8V system rails.

Does the MAX6723UTWGD3+T support monitoring a third voltage, and how is it configured?

Yes, the MAX6723UTWGD3+T supports third-voltage monitoring via its RSTIN pin, which compares the applied voltage against an internal 626.5mV reference. To monitor a third supply (e.g., 2.5V or 1.8V), connect a resistor divider between that supply and ground, with the midpoint fed to RSTIN. The MAX6723UTWGD3+T datasheet provides the formula V_{EXT_TH} = 626.5mV × ((R1 + R2)/R2) for setting the trip point.

What is the function of the WDI pin on the MAX6723UTWGD3+T, and what timing applies?

The WDI (Watchdog Input) pin on the MAX6723UTWGD3+T monitors microprocessor activity: a rising or falling edge clears the watchdog timer. After reset, it enters a 35s minimum startup timeout; upon first WDI transition, it switches to 1.12s minimum normal timeout. If no edge occurs within the active timeout period, MAX6723UTWGD3+T asserts RST for 210ms. This dual-mode behavior prevents false resets during boot while ensuring rapid fault detection during runtime.

Is the reset output of the MAX6723UTWGD3+T open-drain or push-pull, and what are the drive requirements?

The MAX6723UTWGD3+T features an open-drain RST output (Pin 1), requiring an external pullup resistor to VCC1 or another logic rail. It sinks up to 3.2mA when asserted (VOL ≤ 0.4V at VCC1 ≥ 4.5V) and exhibits ≤0.5µA leakage when deasserted. This configuration enables wired-OR reset bus architectures and compatibility with bidirectional µP reset pins - a key distinction from push-pull variants like MAX6724UTWGD3+T.

What is the minimum supply voltage at which the MAX6723UTWGD3+T guarantees correct reset output logic state?

The MAX6723UTWGD3+T guarantees correct reset output logic state - i.e., valid high/low assertion - as long as either VCC1 or VCC2 remains above 0.8V. This specification is explicitly guaranteed in the Absolute Maximum Ratings and Electrical Characteristics tables, enabling reliable operation during deep brownout conditions where other supervisors may fail unpredictably. This behavior is intrinsic to the MAX6723UTWGD3+T's internal biasing and comparator design.