Analog Devices Inc./Maxim Integrated MAX6726KASHD3+T

Overview

MAX6726KASHD3+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 RSTIN input (626.5mV reference). It provides push-pull active-high RST and active-low RST outputs, manual reset input, watchdog timer with 35s startup/1.12s normal timeout, and operates from -40°C to +85°C. It ensures reliable system reset in multivoltage embedded power management.

For engineers reviewing the MAX6726KASHD3+T datasheet, MAX6726KASHD3+T pinout, MAX6726KASHD3+T application, or MAX6726KASHD3+T equivalent, this page delivers verified specifications, exact pin functions, dual-reset output behavior, watchdog timing architecture, and validated alternative parts for voltage-monitoring designs requiring guaranteed reset validity down to VCC = 0.8V.

Technical Context

The MAX6726KASHD3+T implements a dual-mode watchdog timer: a 35s minimum initial timeout after any reset event (power-up, MR, or watchdog expiry), followed by a 1.12s minimum normal timeout triggered by the first WDI edge. Its reset logic guarantees correct output state when either VCC1 or VCC2 ≥ 0.8V, using factory-trimmed thresholds with 20ppm/°C tempco and 0.5% hysteresis referenced to typical VTH.

This device integrates three independent voltage monitors - primary (VCC1), secondary (VCC2), and auxiliary (RSTIN) - each with dedicated comparators feeding a shared reset timeout timer. The RSTIN input accepts external resistor-divider networks to monitor voltages as low as 0.62V, while PFO is absent (no power-fail function per Selector Guide).

Key Specifications

Pinout & Package

MAX6726KASHD3+T is housed in an 8-pin SOT23-8 package (2.0mm × 2.1mm × 1.25mm), surface-mount, lead-free (+T suffix), with exposed pad for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6726KASHD3+T, MAX6725KAHSD3+T offers identical monitoring accuracy but requires external pullups due to open-drain outputs, while TPS3808G33DBVR reduces functionality to single-rail supervision - making MAX6726KASHD3+T uniquely suited for compact, feature-complete triple-voltage supervision with dual-output drive capability.

Availability

MAX6726KASHD3+T is available at Aetrix Electronics and suitable for industrial PLC power management, telecom line card supervision, medical diagnostic imaging subsystems, and automotive ADAS camera modules requiring stable component supply, guaranteed reset behavior down to 0.8V, and dual-output reset signaling.

Supply support for MAX6726KASHD3+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 deep expertise in supervisory and power-management solutions.

The MAX6715–MAX6729 family was engineered specifically for space-constrained multivoltage systems requiring simultaneous monitoring of primary, secondary, and auxiliary rails - delivering integrated reliability without external components.

FAQ

What is the exact reset timeout period for MAX6726KASHD3+T?

The MAX6726KASHD3+T has a nominal reset timeout period of 210ms, with a minimum specified value of 140ms and maximum of 280ms over temperature. This timeout begins when all monitored supplies (VCC1, VCC2, and RSTIN) rise above their respective thresholds and ends with deassertion of both RST outputs. The D3 suffix in the part number explicitly denotes this 210ms typical timeout value per the Reset Timeout Period Suffix Guide.

Does MAX6726KASHD3+T include a power-fail input/output (PFI/PFO) function?

No, MAX6726KASHD3+T does not include PFI or PFO functionality. According to the official Selector Guide, MAX6726 supports manual reset (MR), watchdog input (WDI), and triple-voltage monitoring (VCC1, VCC2, RSTIN), but lacks power-fail circuitry. Only MAX6728 and MAX6729 variants in the family integrate PFI/PFO. Using MAX6726KASHD3+T for power-fail detection requires external circuitry or selection of a different variant.

What are the voltage threshold levels set by the 'ASH' suffix in MAX6726KASHD3+T?

The 'ASH' suffix in MAX6726KASHD3+T specifies VCC1 = 4.625V (A = 4.625V) and VCC2 = 3.075V (H = 3.075V) factory-trimmed reset thresholds, per the Reset Voltage Threshold Suffix Guide. These values are guaranteed over temperature with ±125mV and ±75mV tolerances respectively, enabling precise supervision of standard 5V and 3.3V rails without external adjustment.

Can MAX6726KASHD3+T operate with VCC1 = 2.5V and VCC2 = 1.8V?

Yes, MAX6726KASHD3+T supports VCC1 from 1.8V to 5.0V and VCC2 from 0.9V to 3.3V per datasheet specifications. At VCC1 = 2.5V and VCC2 = 1.8V, the device remains fully functional: reset outputs retain valid logic states (VOH ≥ 0.8×VCC1, VOL ≤ 0.4V), supply current drops to ~10µA, and all monitoring thresholds remain accurate. The 0.8V minimum VCC guarantee ensures robustness during brownout conditions.

How does the watchdog timer behave after power-up in MAX6726KASHD3+T?

Upon power-up, MAX6726KASHD3+T enters a 35s minimum initial watchdog mode. During this period, the WDI input must transition at least once to trigger the switch to the 1.12s minimum normal timeout mode. If no WDI edge occurs within 35s, the watchdog expires and asserts reset. This architecture prevents false timeouts during lengthy system boot sequences while ensuring rapid fault detection once operational - a behavior confirmed in the Detailed Description section.