Analog Devices Inc./Maxim Integrated MAX6727KASYD3-T

Overview

MAX6727KASYD3-T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in an 8-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 outputs with 210ms minimum timeout and supports manual reset, watchdog timer, and power-fail monitoring. It ensures reliable system boot and brownout recovery in multivoltage embedded power rails.

For engineers reviewing the MAX6727KASYD3-T datasheet, MAX6727KASYD3-T pinout, MAX6727KASYD3-T application, or MAX6727KASYD3-T equivalent, key selection criteria include dual independent open-drain RST outputs, 3-supply monitoring capability, guaranteed reset validity down to VCC1/VCC2 = 0.8V, low 14µA typical supply current, and -40°C to +85°C industrial temperature operation.

Technical Context

The MAX6727KASYD3-T integrates three independent voltage monitors: primary (VCC1), secondary (VCC2), and auxiliary (RSTIN), each with factory-trimmed or resistor-divider–adjustable thresholds. Its dual open-drain RST outputs are driven by identical internal logic but electrically isolated for flexible reset distribution across subsystems.

It implements a dual-mode watchdog timer-35s minimum startup period followed by 1.12s minimum normal timeout-and includes a manual reset input with 50kΩ internal pullup and glitch rejection. All reset assertions trigger a guaranteed 210ms minimum timeout period before deassertion.

Key Specifications

Pinout & Package

MAX6727KASYD3-T is housed in an 8-pin SOT23-8 package (2.0mm × 2.1mm × 1.25mm), optimized for space-constrained PCB layouts while maintaining thermal performance and manufacturability in high-volume SMT assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6727KASYD3-T, MAX6725KAUTD3-T offers push-pull reset capability but sacrifices dual open-drain flexibility, while TPS3808G33DBVR reduces feature set and monitoring scope to lower cost-neither provides the coordinated triple-supply, dual-RST, and watchdog functionality required for complex embedded systems.

Availability

MAX6727KASYD3-T is available at Aetrix Electronics and suitable for industrial PLC power management, telecom line card supervision, medical imaging sensor modules, and automotive ADAS camera ECUs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6727KASYD3-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, sensing, and connectivity applications, with leadership in supervisory, PMIC, and interface solutions.

The MAX6715–MAX6729 family delivers ultra-low-voltage, multirail microprocessor supervision targeting space- and power-constrained embedded systems requiring coordinated reset, watchdog, and power-fail signaling.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6727KASYD3-T?

The MAX6727KASYD3-T has a factory-trimmed VCC1 reset threshold of 4.625V (±1.5% over temperature), corresponding to the 'SY' suffix in its part number. This value is guaranteed across the full -40°C to +85°C operating range and defines the precise voltage at which the device asserts reset if VCC1 falls below this level. The MAX6727KASYD3-T uses this threshold to protect systems relying on stable 4.6V rails such as industrial I/O interfaces.

Does the MAX6727KASYD3-T support monitoring a third supply voltage, and how is it configured?

Yes, the MAX6727KASYD3-T supports third-supply monitoring via its RSTIN/PFI pin, which uses an internal 626.5mV reference to enable adjustable threshold detection down to 0.62V. Configuration requires an external resistor divider between the target supply and ground, with RSTIN connected to the divider midpoint. The MAX6727KASYD3-T guarantees 25nA max input current at RSTIN, allowing high-value resistors to minimize system power consumption while maintaining accuracy.

How does the dual open-drain RST output architecture of the MAX6727KASYD3-T benefit system design?

The MAX6727KASYD3-T provides two independent open-drain RST outputs (RST1 and RST2) driven by identical internal logic, enabling simultaneous yet electrically isolated reset signaling to separate subsystems-such as CPU core and peripheral domains-without contention or level-shifting components. This architecture simplifies PCB routing, eliminates risk of bus conflicts, and supports fail-safe partitioning in safety-critical applications. The MAX6727KASYD3-T's dual-RST capability replaces two discrete supervisors in multirail systems.

What is the watchdog timeout behavior of the MAX6727KASYD3-T, and how does it differ between startup and normal operation?

The MAX6727KASYD3-T implements a dual-mode watchdog timer: after any reset event (power-up, brownout, MR, or watchdog timeout), it enters a 35s minimum startup mode to accommodate lengthy system initialization, then transitions to a 1.12s minimum normal timeout period upon the first valid WDI edge. This prevents spurious resets during boot while ensuring rapid detection of runtime hangs. The MAX6727KASYD3-T's watchdog is fully integrated and requires no external components beyond the WDI connection.

Is the MAX6727KASYD3-T compatible with systems requiring reset assertion down to very low supply voltages?

Yes, the MAX6727KASYD3-T guarantees valid reset output logic states even when VCC1 or VCC2 drops to 0.8V-well below typical silicon operating limits. This ensures deterministic brownout response in deep undervoltage conditions where other supervisors may fail silently. The MAX6727KASYD3-T achieves this via robust internal biasing and comparator design, making it suitable for battery-powered or unregulated supply applications where voltage collapse must be reliably detected and acted upon.