Analog Devices Inc./Maxim Integrated MAX6726AKALTD3+

Overview

MAX6726AKALTD3+ from Maxim Integrated is a dual-voltage microprocessor supervisory IC in an 8-pin SOT23 package, monitoring VCC1 (4.625V threshold) and VCC2 (3.075V threshold) with 210ms reset timeout, push-pull active-low RST output, manual-reset input, and watchdog timer. It guarantees valid reset assertion down to VCC1 or VCC2 = 0.8V and draws only 14µA typical supply current at 3.6V - used in telecom power sequencing and industrial controller brownout protection.

For engineers reviewing the MAX6726AKALTD3+ datasheet, MAX6726AKALTD3+ pinout, MAX6726AKALTD3+ application, or MAX6726AKALTD3+ equivalent, key selection criteria include dual-supply voltage thresholds (VTH1 = 4.625V, VTH2 = 3.075V), 210ms min reset timeout, push-pull RST output referenced to VCC1, guaranteed operation down to 0.8V supply, and integrated watchdog with 35s startup/1.12s normal timeout.

Technical Context

The MAX6726AKALTD3+ implements independent voltage comparators for VCC1 and VCC2, each with factory-trimmed thresholds (4.625V and 3.075V respectively), hysteresis of 0.5%, and temperature coefficient of 20ppm/°C. Its reset logic asserts RST low when either supply falls below its threshold and holds it for ≥210ms after both supplies recover.

It integrates a dual-mode watchdog timer: 35s minimum initial timeout after any reset event, followed by 1.12s minimum normal-mode timeout triggered by WDI edge transitions. The manual-reset input (MR) features internal 50kΩ pullup to VCC1 and 1µs minimum pulse width detection.

Key Specifications

Pinout & Package

MAX6726AKALTD3+ uses an 8-pin SOT23 package (3.0mm × 1.7mm × 1.3mm height) with exposed pad for thermal performance. Pin 1 is marked with dot; pin numbering follows standard SOT23-8 convention (counterclockwise from mark).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6725AKALTD3+, the MAX6726AKALTD3+ eliminates external pullup components and simplifies µP interface; versus TPS3808G33DBVR, it delivers comprehensive dual-rail supervision with watchdog and power-fail monitoring - essential for complex embedded systems requiring robust fault coverage.

Availability

MAX6726AKALTD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, medical imaging devices, and automotive ADAS modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6726AKALTD3+ 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, emphasizing reliability, low power, and integration.

The MAX6715A–MAX6729A family delivers ultra-low-voltage microprocessor supervisory circuits optimized for multivoltage systems requiring simultaneous monitoring of primary and secondary rails with guaranteed operation down to 0.8V.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6726AKALTD3+?

The MAX6726AKALTD3+ has factory-trimmed reset thresholds of 4.625V (±125mV) for VCC1 and 3.075V (±75mV) for VCC2, as defined by the "AL" suffix per Maxim's Reset Voltage Threshold Suffix Guide. These values are measured at 25°C with specified tolerances over -40°C to +125°C operating range. The MAX6726AKALTD3+ does not support adjustable thresholds for VCC1 or VCC2 - only the RSTIN input offers external adjustment capability.

Does the MAX6726AKALTD3+ support watchdog functionality, and what are its timing modes?

Yes, the MAX6726AKALTD3+ includes a dual-mode watchdog timer with two distinct timeout periods: a 35s minimum startup mode activated after every reset event (power-up, MR assertion, or watchdog timeout), followed by a 1.12s minimum normal mode that begins after the first valid WDI transition. This architecture accommodates lengthy boot sequences while enforcing tight runtime software liveness checks - a key differentiator from single-mode watchdog supervisors.

What is the function of Pin 6 (RSTIN) on the MAX6726AKALTD3+, and how is it used?

Pin 6 (RSTIN) on the MAX6726AKALTD3+ is an adjustable reset comparator input with a fixed 626mV internal reference voltage. It enables monitoring of a third supply rail (e.g., 1.2V core voltage) using an external resistor divider. When the divided voltage at RSTIN falls below 626mV, the device asserts reset. The MAX6726AKALTD3+ guarantees RSTIN input current ≤±100nA, allowing use of high-value resistors to minimize system power consumption.

How does the MAX6726AKALTD3+ ensure reliable reset operation during severe supply droop?

The MAX6726AKALTD3+ guarantees valid reset output logic states even when VCC1 or VCC2 drops to 0.8V - significantly lower than most competing supervisors. This is achieved through proprietary biasing and comparator design that maintains reference stability and output driver functionality at ultra-low supply voltages. As a result, the MAX6726AKALTD3+ can assert clean reset signals during deep brownout conditions where other devices would lose output control.

What package type and pin count does the MAX6726AKALTD3+ use, and is it RoHS-compliant?

The MAX6726AKALTD3+ uses an 8-pin SOT23 package (3.0mm × 1.7mm footprint, 1.3mm height) with exposed thermal pad. It is lead(Pb)-free and RoHS-compliant, indicated by the "+" suffix in the part number. This compact, surface-mount package supports high-density PCB layouts and meets JEDEC moisture sensitivity level 1 (MSL-1) requirements for unlimited floor life at ambient conditions.