Analog Devices Inc./Maxim Integrated MAX6727KAVHD3+T

Overview

MAX6727KAVHD3+T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, monitoring VCC1 (primary), VCC2 (secondary), and RSTIN (auxiliary) supply rails with factory-trimmed thresholds of 2.925V (VTH1), 2.188V (VTH2), and 626.5mV (RSTIN reference). It provides two open-drain active-low reset outputs (RST, RST2), manual reset input (MR), watchdog timer (35s startup / 1.12s normal timeout), and operates from -40°C to +85°C. It ensures reliable system boot and brownout recovery in multivoltage embedded power management.

For engineers reviewing the MAX6727KAVHD3+T datasheet, MAX6727KAVHD3+T pinout, MAX6727KAVHD3+T application, or MAX6727KAVHD3+T equivalent, key selection criteria include dual open-drain RST outputs, 210ms (min) reset timeout, guaranteed reset validity down to VCC1/VCC2 = 0.8V, and compatibility with low-voltage core/I/O rail supervision in space-constrained industrial and telecom systems.

Technical Context

The MAX6727KAVHD3+T integrates three independent voltage comparators - one for VCC1 (2.925V threshold), one for VCC2 (2.188V), and one for RSTIN (626.5mV internal reference) - each feeding into a shared reset timeout timer. Its dual open-drain RST outputs are independently driven by the same logic state but electrically isolated, enabling separate reset signaling to different subsystems without contention.

It 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 timeout triggered by WDI edge transitions. The MR input features a 50kΩ internal pullup to VCC1 and 200ns propagation delay, while RSTIN supports externally adjustable thresholds via resistor dividers with ≤25nA input leakage.

Key Specifications

Pinout & Package

MAX6727KAVHD3+T is housed in an 8-pin SOT23-8 package (2.0mm × 2.1mm × 1.25mm), optimized for high-density PCB layouts in telecom and portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6727KAVHD3+T, MAX6725KAHVD3+T offers push-pull RST2 but omits RSTIN functionality, while TPS3808G33DBVR reduces quiescent current by 82% yet sacrifices triple-supply flexibility and MR support - making MAX6727KAVHD3+T optimal for compact, multirail systems demanding full feature parity.

Availability

MAX6727KAVHD3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, medical imaging modules, and automotive ADAS ECUs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6727KAVHD3+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 leader specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed specifically for space-constrained multivoltage systems requiring precise, low-power supervision of primary, secondary, and auxiliary rails - with emphasis on robustness under brownout and transient conditions.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6727KAVHD3+T?

The MAX6727KAVHD3+T has a factory-trimmed VCC1 reset threshold of 2.925V (typical), with ±1.5% tolerance over temperature. This value is defined by the "AV" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is validated across the full -40°C to +85°C operating range. The MAX6727KAVHD3+T uses this threshold to supervise 3.3V I/O rails with margin against dropout.

Does the MAX6727KAVHD3+T support monitoring a 1.2V core supply?

Yes - the MAX6727KAVHD3+T supports 1.2V core monitoring via its RSTIN pin, which references an internal 626.5mV comparator. Using a resistor divider (e.g., R1 = 1.18MΩ, R2 = 1MΩ), the external threshold becomes 1.2V. The MAX6727KAVHD3+T guarantees ≤25nA RSTIN input current, enabling high-impedance dividers that minimize system power draw.

How does the dual RST output architecture of the MAX6727KAVHD3+T improve system reliability?

The MAX6727KAVHD3+T provides two independent open-drain RST outputs: RST (VCC1-referenced) and RST2 (VCC2-referenced). This allows separate reset signaling to distinct subsystems - for example, RST to a microcontroller and RST2 to an analog sensor - preventing fault propagation. The MAX6727KAVHD3+T maintains electrical isolation between outputs while sharing the same supervision logic, enhancing fault containment.

What is the watchdog timeout behavior of the MAX6727KAVHD3+T during system boot?

The MAX6727KAVHD3+T implements a dual-mode watchdog: after any reset event (power-up, MR, or timeout), it enters a 35s minimum startup period to accommodate lengthy boot sequences. Once the first valid WDI edge occurs, it switches to a 1.12s minimum normal timeout. This behavior is hard-coded in the MAX6727KAVHD3+T and requires no configuration - ensuring robust supervision across boot and runtime phases.

Can the MAX6727KAVHD3+T operate with VCC1 = 2.5V and VCC2 = 1.8V simultaneously?

Yes - the MAX6727KAVHD3+T is fully specified to operate with VCC1 as low as 1.8V and VCC2 as low as 0.9V, including simultaneous 2.5V/1.8V operation. Its reset outputs remain valid down to VCC1 or VCC2 = 0.8V, and supply current is characterized at these voltages (e.g., 10µA typical at VCC1 = 2.5V). This makes the MAX6727KAVHD3+T suitable for modern low-voltage SoC platforms.