Analog Devices Inc./Maxim Integrated MAX6727AKAWGD3+T

Overview

MAX6727AKAWGD3+T from Maxim Integrated is a dual-supply ultra-low-voltage microprocessor supervisory circuit with factory-trimmed reset thresholds (VCC1 = 4.625 V, VCC2 = 3.075 V), 280 ms minimum reset timeout, and open-drain RST/RST2 outputs. It monitors primary (1.8–5.0 V) and secondary (0.9–3.3 V) supplies, asserts reset below threshold, and maintains reset for ≥280 ms after recovery - used in telecom power management and industrial embedded controllers requiring reliable brownout detection.

For engineers reviewing the MAX6727AKAWGD3+T datasheet, MAX6727AKAWGD3+T pinout, MAX6727AKAWGD3+T application, or MAX6727AKAWGD3+T equivalent, key selection criteria include dual-voltage monitoring capability, guaranteed reset validity down to VCC1/VCC2 = 0.8 V, low 14 µA typical supply current at 3.6 V, and SOT23-8 package compatibility with multilayer PCB thermal constraints (θJA = 180°C/W).

Technical Context

The MAX6727AKAWGD3+T implements independent voltage comparators for VCC1 and VCC2, each with 0.5% hysteresis referenced to their respective threshold voltages. Its reset logic combines ORed fault conditions (VCC1/VCC2 undervoltage, MR assertion, or WDI timeout) and enforces a fixed 280 ms minimum reset pulse width via an internal timer.

This device belongs to the MAX6715A–MAX6729A family and features an externally adjustable RSTIN input (626.5 mV reference) for triple-voltage monitoring, manual-reset input with 50 kΩ internal pullup to VCC1, and watchdog disable-by-open functionality - all operating across –40°C to +125°C without external components.

Key Specifications

Pinout & Package

MAX6727AKAWGD3+T is housed in an 8-pin SOT23 package (package code K8SN+1, outline 21-0078), optimized for high-density layouts with θJA = 180°C/W on multilayer boards. Thermal design requires attention to copper pour and vias beneath the exposed pad (if present per land pattern 90-0176).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6727AKAWGD3+T, MAX6726AKAWGD3+T simplifies board layout by eliminating pullup resistors but sacrifices bus-sharing flexibility, while TPS3808G33DBVR reduces cost and size at the expense of losing secondary supply monitoring and redundant reset signaling.

Availability

MAX6727AKAWGD3+T is available at Aetrix Electronics and suitable for telecom power sequencing, industrial PLC controller supervision, and automotive ADAS domain controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6727AKAWGD3+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 demanding industrial, automotive, and communications applications, with emphasis on reliability, low power, and integration.

The MAX6715A–MAX6729A product line delivers compact, ultra-low-voltage supervisory circuits for multirail systems where simultaneous monitoring of primary and secondary supplies is essential to system-level functional safety.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6727AKAWGD3+T?

The MAX6727AKAWGD3+T has factory-trimmed reset thresholds of 4.625 V (±125 mV) for VCC1 and 3.075 V (±75 mV) for VCC2, corresponding to suffix codes 'K' (VCC1) and 'A' (VCC2) in the ordering guide. These values are specified at TA = +25°C and exhibit ±20 ppm/°C tempco across –40°C to +125°C. The MAX6727AKAWGD3+T datasheet confirms these thresholds are guaranteed over full temperature and voltage ranges.

Does the MAX6727AKAWGD3+T support manual reset functionality, and how is it implemented?

Yes, the MAX6727AKAWGD3+T includes an active-low manual-reset input (MR) on Pin 3 with a 50 kΩ internal pullup to VCC1. Pulling MR low forces immediate reset assertion, which remains active for the full 280 ms timeout period after MR returns high. The MAX6727AKAWGD3+T requires only a momentary switch to GND - no external debounce or pullup components are needed, simplifying field-service and test-mode integration.

Can the MAX6727AKAWGD3+T monitor a third voltage rail, and what is the reference voltage for that input?

Yes, the MAX6727AKAWGD3+T supports triple-voltage monitoring via its RSTIN input (Pin 6), which uses a precise 626.5 mV internal reference voltage. An external resistor divider connected between the auxiliary supply and GND sets the trip point using V_{EXT_TH} = 626.5 mV × ((R1 + R2)/R2). This feature enables monitoring of rails as low as 0.62 V without additional ICs, and the MAX6727AKAWGD3+T guarantees RSTIN input current ≤ ±100 nA for minimal divider loading.

What is the thermal performance of the MAX6727AKAWGD3+T in its SOT23-8 package?

The MAX6727AKAWGD3+T in its 8-pin SOT23 package (K8SN+1) has a junction-to-ambient thermal resistance (θ_JA) of 180°C/W on a multilayer PCB, and junction-to-case (θ_JC) of 60°C/W. These values assume proper land pattern 90-0176 implementation with thermal vias. The MAX6727AKAWGD3+T maximum junction temperature is +150°C, allowing continuous operation at +125°C ambient when power dissipation remains below 333 mW (calculated as (150 – 125) / 180).

How does the MAX6727AKAWGD3+T handle short VCC transients, and what is the immunity specification?

The MAX6727AKAWGD3+T is immune to negative-going VCC transients ≤20 µs in duration when the overdrive is 100 mV below the reset threshold, as verified in the "Maximum VCC Transient Duration vs. Reset Threshold Overdrives" graph. This immunity prevents spurious resets during switching noise or ESD events. The MAX6727AKAWGD3+T achieves this via internal filtering and comparator hysteresis, and a 0.1 µF bypass capacitor near VCC pins further enhances robustness without requiring additional circuitry.