Analog Devices Inc./Maxim Integrated MAX6720UTLTD3+T

Overview

MAX6720UTLTD3+T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in SOT23-6 package, monitoring VCC1 (4.625V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference). It asserts active-low push-pull reset for ≥210ms after any supply drop, supports manual reset and watchdog timer, and operates from -40°C to +85°C. It ensures reliable power-up sequencing and brownout protection in multivoltage embedded systems.

For engineers reviewing the MAX6720UTLTD3+T datasheet, MAX6720UTLTD3+T pinout, MAX6720UTLTD3+T application, or MAX6720UTLTD3+T equivalent, key selection criteria include confirmed dual-supply monitoring with factory-trimmed thresholds, 210ms min reset timeout, push-pull RST output referenced to VCC1, guaranteed reset validity down to VCC1/VCC2 = 0.8V, and integrated watchdog with 35s startup/1.12s normal timeout.

Technical Context

The MAX6720UTLTD3+T implements independent voltage comparators for VCC1 and VCC2 with factory-trimmed thresholds (4.625V and 3.075V respectively), plus a high-impedance RSTIN input tied to a 626.5mV internal reference for third-voltage monitoring via external resistor divider. Its reset logic combines OR-ed fault conditions (VCC1/VCC2 undervoltage, RSTIN low, MR low) with a monolithic timeout counter.

It features a dual-mode watchdog timer: 35s minimum initial timeout after reset for system boot, transitioning to 1.12s minimum normal timeout after first WDI edge; reset outputs are push-pull active-low referenced to VCC1, with VOL ≤ 0.4V at ISINK = 3.2mA and VOH ≥ 0.8×VCC1 at ISOURCE = 800µA.

Key Specifications

Pinout & Package

SOT23-6 package: 2.9mm × 1.6mm × 1.1mm body, gull-wing leads, thermal pad optional. RoHS-compliant lead-free construction (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720UTLTD5+T and TPS3808G33DBVR, the MAX6720UTLTD3+T uniquely delivers factory-trimmed dual-threshold monitoring (4.625V/3.075V), 210ms reset timeout, and RSTIN-based third-voltage supervision in one SOT23-6 IC-enabling compact, reliable power integrity in multirail embedded systems without design compromises.

Availability

MAX6720UTLTD3+T is available at Aetrix Electronics and suitable for multivoltage systems, industrial PLCs, and battery-powered medical sensors requiring stable component supply, guaranteed reset timing, and industrial-temperature operation.

Supply support for MAX6720UTLTD3+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 management, sensing, and interface applications across industrial, automotive, and communications markets.

The MAX6715–MAX6729 family targets space-constrained embedded systems needing reliable, ultra-low-power supervision of multiple supply rails-with emphasis on factory-trimmed accuracy, flexible timeout, and integrated watchdog functionality.

FAQ

What is the exact reset timeout period specified for MAX6720UTLTD3+T?

The MAX6720UTLTD3+T has a minimum reset timeout period of 210ms, as defined by the "D3" suffix in its part number per Maxim's Reset Timeout Period Suffix Guide. This is the guaranteed minimum duration the RST output remains asserted after all monitored voltages recover above their thresholds, ensuring sufficient time for power stabilization and clock lock in microprocessor systems. The typical value is 210ms, with maximum 280ms under worst-case conditions.

Does MAX6720UTLTD3+T support monitoring a third voltage, and how is it implemented?

Yes, MAX6720UTLTD3+T supports third-voltage monitoring via its RSTIN pin, which connects to an internal 626.5mV precision reference. To monitor an auxiliary supply (e.g., 1.2V or 1.8V), a resistor divider scales the target voltage so that it equals 626.5mV at the desired trip point. The MAX6720UTLTD3+T asserts reset when RSTIN falls below this reference, providing flexible triple-supply supervision without external comparators.

What are the voltage threshold levels for VCC1 and VCC2 on MAX6720UTLTD3+T?

The MAX6720UTLTD3+T uses the "LT" suffix per Maxim's Reset Voltage Threshold Suffix Guide, specifying VCC1 = 4.625V (±125mV) and VCC2 = 3.075V (±75mV) factory-trimmed falling thresholds. These values are laser-trimmed during production and guaranteed over temperature, eliminating need for external resistor networks when supervising standard 4.63V I/O and 3.3V logic rails.

Is MAX6720UTLTD3+T compatible with manual reset pushbuttons, and what is the input behavior?

Yes, MAX6720UTLTD3+T includes an active-low manual reset input (MR) with a 50kΩ internal pullup to VCC1. A momentary switch from MR to GND pulls the input low, forcing immediate reset assertion for the full 210ms timeout period-even if the switch is released early. No external components are required, and the 1µs minimum pulse width and 100ns glitch rejection ensure noise immunity in industrial environments.

What output drive capability does the RST pin of MAX6720UTLTD3+T provide?

The RST pin of MAX6720UTLTD3+T is a push-pull active-low output referenced to VCC1. It sinks up to 3.2mA while maintaining VOL ≤ 0.4V (at VCC1 ≥ 4.5V), and sources up to 800µA while ensuring VOH ≥ 0.8×VCC1. This eliminates need for external pullup resistors, simplifies interface to µP reset pins, and supports direct driving of downstream logic or enable inputs without level-shifting.