Analog Devices Inc./Maxim Integrated MAX6723UTYDD3+

Overview

MAX6723UTYDD3+ 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 provides open-drain active-low reset with 210ms minimum timeout, watchdog timer (35s startup / 1.12s normal), and manual reset input. Used in multivoltage telecom and industrial systems requiring reliable power-up sequencing and brownout protection.

For engineers reviewing the MAX6723UTYDD3+ datasheet, MAX6723UTYDD3+ pinout, MAX6723UTYDD3+ application, or MAX6723UTYDD3+ equivalent, key selection criteria include dual-supply monitoring range (1.8–5.0V primary, 0.9–3.3V secondary), 626.5mV RSTIN reference for third-voltage monitoring down to 0.62V, guaranteed reset validity at VCC ≥ 0.8V, 14µA typical supply current, and SOT23-6 footprint compatibility.

Technical Context

The MAX6723UTYDD3+ integrates three independent voltage monitors: factory-trimmed comparators for VCC1 and VCC2, plus a high-impedance RSTIN input referenced to a 626.5mV internal bandgap. Its reset logic asserts RST low when any monitored voltage falls below its threshold and holds for a fixed 210ms (min) timeout after recovery.

It includes a dual-mode watchdog timer-35s minimum initial period for system boot, then 1.12s minimum normal mode-with edge-triggered reset clearing. The manual reset (MR) input features 50kΩ internal pullup and 200ns MR-to-reset delay, while immunity to sub-100ns VCC transients ensures robust operation in noisy environments.

Key Specifications

Pinout & Package

MAX6723UTYDD3+ uses a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm height), optimized for space-constrained PCB layouts in portable and telecom equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6723UTYDD3+, MAX6724UTYDD3+ offers push-pull drive for simpler interfacing but sacrifices bidirectional µP compatibility, while TPS3808G33DBVR reduces quiescent current by 82% but omits dual/third-supply monitoring entirely-making it unsuitable for multivoltage system supervision.

Availability

MAX6723UTYDD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, network routers, and medical imaging subsystems requiring stable component supply across extended product lifecycles.

Supply support for MAX6723UTYDD3+ 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, communications, and computing applications.

The MAX6715–MAX6729 family delivers compact, low-power supervisory solutions for multivoltage embedded systems-specifically engineered to replace discrete resistor-comparator-reset circuits with integrated, factory-trimmed accuracy and watchdog intelligence.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6723UTYDD3+?

The MAX6723UTYDD3+ has a factory-trimmed VCC1 reset threshold of 4.625V (±1.5% over temperature). This value is encoded in the "YT" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is verified across the full -40°C to +85°C operating range. The threshold remains stable due to internal bandgap referencing and 20ppm/°C tempco.

Does the MAX6723UTYDD3+ support monitoring a third voltage, and how is it configured?

Yes, the MAX6723UTYDD3+ supports third-voltage monitoring via the RSTIN pin, which references an internal 626.5mV precision bandgap. To configure, connect an external resistor divider from the target supply to GND, with the midpoint fed to RSTIN. The monitored voltage threshold equals 626.5mV × (R1 + R2)/R2, enabling supervision of supplies as low as 0.62V with minimal current draw.

What is the reset timeout period for the MAX6723UTYDD3+, and is it adjustable?

The MAX6723UTYDD3+ has a fixed minimum reset timeout period of 210ms, indicated by the "D3" suffix in its part number. This value is factory-programmed and not user-adjustable. The timeout begins when all monitored voltages rise above their thresholds and ends with RST deassertion, ensuring sufficient time for microprocessor initialization and peripheral stabilization.

How does the watchdog timer function on the MAX6723UTYDD3+ differ from standard implementations?

The MAX6723UTYDD3+ implements a dual-mode watchdog: a 35s minimum startup period after any reset event (power-up, MR, or watchdog timeout), followed by a 1.12s minimum normal period triggered by the first WDI edge. This architecture prevents false timeouts during boot while enabling rapid fault detection during runtime-unlike single-period watchdogs that require software to manage timing windows manually.

Can the MAX6723UTYDD3+ operate reliably when VCC1 drops below 1.0V?

Yes, the MAX6723UTYDD3+ guarantees valid reset output logic state down to VCC1 or VCC2 = 0.8V. This ensures deterministic reset assertion during deep brownout conditions. For operation down to 0V, a 100kΩ pull-down resistor on RST is recommended-but note this applies only to push-pull variants; MAX6723UTYDD3+ uses open-drain RST, so external pullup is mandatory and functional down to 0.8V.