Analog Devices Inc./Maxim Integrated MAX6727KASHD3-T

Overview

MAX6727KASHD3-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 asserts active-low open-drain reset outputs with 210ms minimum timeout, supports manual reset and watchdog timer, and operates from -40°C to +85°C for reliable power sequencing in multivoltage embedded systems.

For engineers reviewing the MAX6727KASHD3-T datasheet, MAX6727KASHD3-T pinout, MAX6727KASHD3-T application, or MAX6727KASHD3-T equivalent, key selection criteria include dual independent open-drain RST outputs, factory-trimmed dual supply thresholds, RSTIN-adjustable third-voltage monitoring down to 0.62V, guaranteed reset validity at VCC ≥ 0.8V, and 14µA typical supply current at 3.6V.

Technical Context

The MAX6727KASHD3-T implements a triple-supply monitoring architecture with independent comparators for VCC1, VCC2, and RSTIN, each feeding into a shared reset timeout timer. Its dual open-drain RST outputs are driven by identical logic but electrically isolated-RST1 referenced to VCC1 and RST2 referenced to VCC2-enabling independent reset signaling to different voltage domains.

It integrates a dual-mode watchdog timer (35s startup / 1.12s normal mode), manual reset with 50kΩ internal pullup, and no power-fail input/output. The device guarantees correct reset state assertion when either VCC1 or VCC2 remains above 0.8V, and uses BiCMOS process for low leakage and stable threshold tempco of 20ppm/°C.

Key Specifications

Pinout & Package

MAX6727KASHD3-T is housed in an 8-pin SOT23 package (JEDEC MO-203AA), with 0.65mm pitch, 2.9mm × 1.6mm body size, and exposed thermal pad (not electrically connected). Pin 1 marked by dot; pins numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6727KASHD3-T, MAX6725KAHBD3-T trades RSTIN adjustability for PFI/PFO functionality and uses push-pull RST for direct µP interface, while TPS3808G33DBVR reduces footprint and complexity at the expense of triple-monitoring capability and threshold flexibility.

Availability

MAX6727KASHD3-T is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, battery-powered medical devices, and network routers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6727KASHD3-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) is a semiconductor company specializing in precision analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed specifically for compact, ultra-low-power multivoltage supervision in space-constrained embedded systems-emphasizing factory-trimmed accuracy, low ICC, and flexible reset architectures.

FAQ

What is the function of the RSTIN pin on the MAX6727KASHD3-T?

The RSTIN pin on the MAX6727KASHD3-T is a high-impedance input that connects to an internal 626.5mV reference comparator, enabling monitoring of a third system voltage via an external resistor divider. When the divided voltage falls below 626.5mV, the device asserts both RST1 and RST2 outputs. Input bias current is under ±25nA, allowing use of high-value resistors to minimize power draw in battery-operated systems.

How does the dual RST output architecture of the MAX6727KASHD3-T improve system design?

The MAX6727KASHD3-T provides two independent open-drain reset outputs-RST1 referenced to VCC1 and RST2 referenced to VCC2-allowing simultaneous but electrically isolated reset signaling to different voltage domains. This eliminates level-shifter requirements and avoids contention when coordinating reset timing between 5V CPU and 3.3V I/O subsystems, simplifying PCB layout and improving noise immunity in mixed-voltage systems.

What reset timeout period is implemented in the MAX6727KASHD3-T?

The MAX6727KASHD3-T implements a 210ms minimum reset timeout period, indicated by the "D3" suffix in its part number. This timeout begins when all monitored voltages (VCC1, VCC2, and RSTIN) rise above their respective thresholds and continues regardless of subsequent voltage fluctuations-ensuring the microprocessor receives a clean, sustained reset pulse long enough for full initialization before release.

Does the MAX6727KASHD3-T support manual reset functionality?

Yes, the MAX6727KASHD3-T includes an active-low manual reset input (MR) with a built-in 50kΩ pullup resistor to VCC1. Pulling MR low forces immediate reset assertion, which remains active for the full 210ms timeout period after MR returns high. The input rejects glitches shorter than 100ns and accepts standard TTL/CMOS logic levels, enabling simple pushbutton or logic-controlled reset initiation without external components.

What is the operating voltage range for VCC1 and VCC2 on the MAX6727KASHD3-T?

The MAX6727KASHD3-T supports VCC1 from 1.8V to 5.0V (with 4.625V factory-trimmed threshold) and VCC2 from 0.9V to 3.3V (with 3.075V factory-trimmed threshold). Crucially, the device guarantees valid reset output logic states as long as either VCC1 or VCC2 remains above 0.8V-providing robust operation during deep brownout conditions common in battery-fed or unregulated power systems.