Analog Devices Inc./Maxim Integrated MAX6727KAWGD3+

Overview

MAX6727KAWGD3+ 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 4.625V/3.075V and 626mV reference, 210ms reset timeout, and open-drain dual RST outputs. It ensures reliable system reset during brownouts in multivoltage embedded systems such as telecom power management and industrial controllers.

For engineers reviewing the MAX6727KAWGD3+ datasheet, MAX6727KAWGD3+ pinout, MAX6727KAWGD3+ application, or MAX6727KAWGD3+ equivalent, key selection criteria include its dual open-drain reset outputs, 626mV adjustable RSTIN threshold for third-rail monitoring, guaranteed reset validity down to VCC = 0.8V, and -40°C to +85°C industrial temperature operation.

Technical Context

The MAX6727KAWGD3+ integrates three independent voltage monitors: VCC1 (4.625V threshold), VCC2 (3.075V threshold), and RSTIN (626mV internal reference). Its dual open-drain RST outputs share identical assertion logic but drive separate pins, enabling independent reset signaling to multiple subsystems without external logic.

It features a 210ms minimum reset timeout period, manual reset input (MR) with 50kΩ internal pullup, and watchdog timer with 35s startup and 1.12s normal mode-though watchdog functionality is not implemented in this variant per Selector Guide. The device operates with 14µA typical supply current at 3.6V and maintains valid reset state down to VCC1 or VCC2 = 0.8V.

Key Specifications

Pinout & Package

MAX6727KAWGD3+ uses an 8-pin SOT23-8 package (3.0mm × 1.6mm × 1.1mm body, 0.65mm pitch), optimized for high-density PCB layouts in space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6727KAWGD3+, MAX6725KAUTD3+ adds PFO functionality and mixed-output drive types at identical monitoring capability, while TPS3808G33DBVR reduces feature set and monitoring scope to achieve lower power and cost-making it unsuitable as a drop-in replacement but viable for simplified designs.

Availability

MAX6727KAWGD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, and medical imaging equipment requiring stable component supply across extended product lifecycles.

Supply support for MAX6727KAWGD3+ 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.

The MAX6715–MAX6729 family delivers ultra-low-voltage supervisory circuits targeting multirail embedded systems where reliability, small size, and guaranteed reset behavior under brownout conditions are critical.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6727KAWGD3+?

The MAX6727KAWGD3+ has factory-trimmed reset thresholds of 4.625V for VCC1 and 3.075V for VCC2, with ±125mV and ±75mV tolerances respectively. These values are fixed by the "KW" suffix per Maxim's Reset Voltage Threshold Suffix Guide and do not require external adjustment. The MAX6727KAWGD3+ guarantees correct reset assertion when either supply drops below these levels.

Does the MAX6727KAWGD3+ include watchdog timer functionality?

No, the MAX6727KAWGD3+ does not implement watchdog timer functionality. Per Maxim's Selector Guide, MAX6727 is explicitly listed without WDI (watchdog input) support. The device provides triple-voltage monitoring and dual open-drain reset outputs only. For watchdog capability, consider MAX6729KAUTD3+ or MAX6721UTWD3+ instead.

How are the two RST outputs on the MAX6727KAWGD3+ configured and used?

The MAX6727KAWGD3+ provides two independent open-drain RST outputs (RST1 on Pin 1 and RST2 on Pin 7), both driven by identical internal logic and asserting simultaneously under the same conditions (VCC1/VCC2/RSTIN fault or MR activation). They enable redundant reset signaling or domain-isolated reset control-e.g., RST1 to CPU and RST2 to FPGA-without requiring external logic or splitters.

Can the MAX6727KAWGD3+ monitor a 1.2V supply using the RSTIN pin?

Yes, the MAX6727KAWGD3+ can monitor a 1.2V supply using the RSTIN pin (Pin 5) with a resistor divider. Since RSTIN compares against a 626mV internal reference, a 1.2V rail requires R1/R2 ≈ 0.91 (e.g., R1 = 91kΩ, R2 = 100kΩ). The MAX6727KAWGD3+'s 25nA max RSTIN input current ensures minimal loading, preserving accuracy with standard 1% resistors.

What is the function of Pin 8 (PFO) on the MAX6727KAWGD3+?

Pin 8 (PFO) on the MAX6727KAWGD3+ is a reserved/no-connect pin. Although labeled PFO in the generic pinout diagram, the MAX6727 variant does not implement power-fail output functionality per Maxim's Selector Guide and Functional Diagram. It must be left unconnected or tied to GND; driving or loading this pin may cause undefined behavior.