Analog Devices Inc./Maxim Integrated MAX6723UTSVD3+T

Overview

MAX6723UTSVD3+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 third supply via RSTIN (626.5mV reference). It asserts active-low open-drain reset for ≥210ms after any monitored voltage drops below threshold or manual reset is triggered, and supports watchdog timeout (35s startup / 1.12s normal mode). Used in telecom power sequencing and battery-backed embedded controllers.

For engineers reviewing the MAX6723UTSVD3+T datasheet, MAX6723UTSVD3+T pinout, MAX6723UTSVD3+T application, or MAX6723UTSVD3+T equivalent, key selection criteria include triple-supply monitoring capability, guaranteed reset validity down to VCC1/VCC2 = 0.8V, 14µA typical supply current at 3.6V, and compatibility with low-voltage core/I/O rail systems requiring precise undervoltage detection and long watchdog startup windows.

Technical Context

The MAX6723UTSVD3+T implements dual independent voltage comparators for VCC1 and VCC2, plus a high-impedance RSTIN input referenced to a 626.5mV internal bandgap. Its reset logic combines OR-ed fault conditions (VCC1/VCC2 undervoltage, RSTIN undervoltage, MR assertion) with a monolithic timeout timer that restarts on any new fault before timeout completion.

It features a dual-mode watchdog: 35s minimum initial timeout after power-up or reset, transitioning to 1.12s minimum normal timeout after first WDI edge detection. The open-drain RST output requires external pullup and remains asserted for 210ms (min) after all monitored voltages recover above thresholds.

Key Specifications

Pinout & Package

MAX6723UTSVD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in portable and telecom modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6723UTSVD3+T, MAX6724UTSVD3+T eliminates external pullup needs but sacrifices bus-sharing flexibility, while TPS3808G33DBVR reduces feature count and cost but cannot replace the triple-monitoring function in safety-critical multi-rail systems.

Availability

MAX6723UTSVD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6723UTSVD3+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 demanding industrial, automotive, and communications applications, with emphasis on reliability and integration.

The MAX6715–MAX6729 family delivers ultra-low-voltage supervisory functions in miniature SOT23 packages, targeting space- and power-constrained embedded systems needing robust multi-rail power monitoring and fail-safe reset control.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6723UTSVD3+T?

The MAX6723UTSVD3+T has a factory-trimmed VCC1 reset threshold of 4.625V, with a guaranteed tolerance of ±125mV (4.500V to 4.750V) over temperature. This value is encoded in the "SV" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is measured under standard conditions with VCC1 ramping downward.

Does the MAX6723UTSVD3+T support monitoring a third voltage below 1.0V?

Yes, the MAX6723UTSVD3+T supports monitoring auxiliary supplies as low as 0.62V via its RSTIN pin, which references an internal 626.5mV bandgap. Using a resistor divider (e.g., R1=100kΩ, R2=100kΩ), a 1.25V supply yields ~626mV at RSTIN-enabling precise sub-1V supervision with standard 1% resistors.

What is the watchdog timeout behavior after power-up for the MAX6723UTSVD3+T?

After power-up or any reset event, the MAX6723UTSVD3+T enters a 35s minimum initial watchdog timeout period. Only after detecting the first valid edge on WDI does it transition to the 1.12s minimum normal timeout mode-ensuring sufficient time for bootloader execution before runtime watchdog enforcement begins.

Can the MAX6723UTSVD3+T operate with VCC1 = 1.8V and still guarantee valid reset output?

Yes, the MAX6723UTSVD3+T guarantees correct reset output logic state when either VCC1 or VCC2 remains greater than 0.8V. At VCC1 = 1.8V, the open-drain RST output maintains valid low-state drive capability (VOL ≤ 0.3V at 100µA sink) and high-impedance release, meeting µP reset interface requirements.

Is an external pullup resistor required for the RST pin on the MAX6723UTSVD3+T?

Yes, the MAX6723UTSVD3+T features an open-drain RST output, requiring an external pullup resistor to a valid logic rail (typically VCC1 or another stable supply). A 10kΩ–100kΩ resistor is recommended; values >100kΩ may increase susceptibility to noise, while <10kΩ increases static current consumption unnecessarily.