Analog Devices Inc./Maxim Integrated MAX6724UTSHD3-T

Overview

MAX6724UTSHD3-T from Maxim Integrated is a triple-voltage microprocessor supervisory IC that monitors VCC1 (primary), VCC2 (secondary), and an externally adjustable RSTIN input down to 0.626V. It asserts an active-low push-pull reset output when any monitored supply falls below its threshold and maintains reset for a guaranteed 210ms (min) timeout period after recovery. Designed for multivoltage embedded systems, it ensures reliable power-on reset and brownout detection in telecom and portable equipment.

For engineers reviewing the MAX6724UTSHD3-T datasheet, MAX6724UTSHD3-T pinout, MAX6724UTSHD3-T application, or MAX6724UTSHD3-T equivalent, key selection criteria include its dual-supply monitoring range (VCC1: 1.575–4.625V, VCC2: 0.788–3.075V), 210ms reset timeout, push-pull RST output referenced to VCC1, and integrated watchdog timer with 35s startup/1.12s normal mode.

Technical Context

The MAX6724UTSHD3-T implements a dual-threshold comparator architecture for independent VCC1 and VCC2 monitoring, plus a dedicated high-impedance RSTIN input with 626.5mV internal reference for third-voltage supervision. Its reset logic combines asynchronous assertion (on threshold violation) with synchronous deassertion after a fixed 210ms timeout, ensuring immunity to short VCC transients.

It integrates a dual-mode watchdog timer: a 35s minimum startup period enables full system initialization post-power-up, followed by a 1.12s minimum normal timeout triggered by WDI edge transitions. The push-pull RST output is rail-to-rail compatible with VCC1 and guaranteed functional down to VCC1 or VCC2 = 0.8V.

Key Specifications

Pinout & Package

MAX6724UTSHD3-T is housed in a 6-pin SOT23-6 package with gull-wing leads, 1.27mm pitch, and 2.9mm × 1.6mm footprint - optimized for space-constrained PCB layouts in portable and networking gear.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720UTSHD3-T and TPS3808G33DBVR, the MAX6724UTSHD3-T uniquely delivers triple-supply monitoring with push-pull reset and integrated dual-mode watchdog in a 6-pin SOT23 - making it the only option capable of replacing discrete supervisors in compact multirail designs without layout changes.

Availability

MAX6724UTSHD3-T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, portable medical devices, and network switch power management requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6724UTSHD3-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 precision analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed to replace discrete reset circuits in multivoltage embedded systems - delivering higher reliability, smaller footprint, and configurable supervision for 1.8V–5.0V supply domains.

FAQ

What is the exact reset timeout period for MAX6724UTSHD3-T?

The MAX6724UTSHD3-T has a guaranteed minimum reset timeout period of 210ms, corresponding to the "D3" suffix in its part number. This is the duration for which the active-low RST output remains asserted after all monitored voltages (VCC1, VCC2, RSTIN) rise above their respective thresholds, or after MR is released. The actual timeout is typically 210ms at +25°C and varies within ±25% over temperature and supply voltage.

Does MAX6724UTSHD3-T support monitoring a 1.2V core supply?

Yes, MAX6724UTSHD3-T supports monitoring a 1.2V core supply via its RSTIN pin using an external resistor divider. With a fixed 626.5mV internal reference, a divider ratio of R1/R2 = (1.2V / 0.6265V) − 1 ≈ 0.914 sets the trip point precisely at 1.2V. The high-impedance RSTIN input draws only ±25nA, enabling use of high-value resistors to minimize power loss.

What is the function of the MR pin on MAX6724UTSHD3-T?

The MR (Manual Reset) pin on MAX6724UTSHD3-T is an active-low input with a 50kΩ internal pullup to VCC1. Pulling MR low forces the RST output low for the full 210ms timeout period, regardless of supply voltage levels. It remains asserted while MR is held low and continues for the timeout duration after MR returns high - enabling hardware-initiated resets via pushbutton or system logic.

Can MAX6724UTSHD3-T be used with a 2.5V VCC1 supply?

Yes, MAX6724UTSHD3-T operates with VCC1 as low as 0.8V and supports 2.5V nominal supplies. However, its factory-trimmed VCC1 threshold is 4.625V (suffix "SH"), so at 2.5V the primary supply will always be below threshold and cause continuous reset assertion. For 2.5V systems, select a variant with lower VCC1 threshold (e.g., "TH" = 2.625V) - the MAX6724UTTHD3-T - not the SH-suffixed MAX6724UTSHD3-T.

Is the RST output of MAX6724UTSHD3-T push-pull or open-drain?

The RST output of MAX6724UTSHD3-T is push-pull, as confirmed by the "U" in the package code (UT = SOT23-6 with push-pull RST) and Selector Guide. It actively drives high (to VCC1) and low (to GND) without requiring an external pullup resistor - simplifying interface to microprocessor reset inputs and reducing component count versus open-drain alternatives.