Analog Devices Inc./Maxim Integrated MAX6366LKA46+T

Overview

The MAX6366LKA46+T from Maxim Integrated is a low-power microprocessor supervisory circuit with integrated watchdog timer, battery-backup switchover, and chip-enable gating. It monitors +4.63V supply voltage (factory preset), asserts active-high open-drain RESET on VCC brownout or watchdog timeout, and switches OUT between VCC and backup battery (VBATT) to maintain CMOS RAM during power failure. Designed for portable equipment and industrial controllers requiring reliable reset and data retention.

For engineers reviewing the MAX6366LKA46+T datasheet, MAX6366LKA46+T pinout, MAX6366LKA46+T application, or MAX6366LKA46+T equivalent, key selection criteria include its 4.63V reset threshold, 1.6s watchdog timeout, 150ms minimum reset timeout, 10µA quiescent current, and SOT23-8 package compatibility with space-constrained µP systems.

Technical Context

The MAX6366LKA46+T implements a precision voltage monitor with ±1.5% threshold accuracy over temperature, a monostable watchdog timer triggered by WDI edge transitions, and bidirectional VCC/BATT switchover with 40mV hysteresis to prevent oscillation during slow VCC decay. Its internal transmission gate provides 1.5ns CE IN-to-CE OUT propagation delay for high-speed memory protection.

Reset assertion is guaranteed down to 1.2V VCC or VBATT, and the device maintains functional integrity during supply transients up to 30µs at 100mV overdrive below VTH. The open-drain RESET output supports wired-OR configurations and level-shifting across voltage domains.

Key Specifications

Pinout & Package

Package: 8-pin SOT23 (3.0mm × 1.7mm × 1.3mm height), lead(Pb)-free, tape-and-reel.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6366PKA46+T and TPS3808G33DBVR, the MAX6366LKA46+T uniquely combines 4.63V precision monitoring, 1.6s watchdog, and seamless battery switchover in a single SOT23-8 package-enabling compact, fail-safe µP systems without external support components.

Availability

MAX6366LKA46+T is available at Aetrix Electronics and suitable for industrial control systems, portable medical devices, and point-of-sale terminals requiring stable component supply and long-term lifecycle support.

Supply support for MAX6366LKA46+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 management, sensing, and connectivity in demanding environments.

The MAX6365–MAX6368 product line delivers ultra-low-power supervisory circuits with integrated battery backup and memory protection, targeting space-constrained µP systems needing robust power-fail response and data retention.

FAQ

What is the factory-set reset threshold voltage for MAX6366LKA46+T?

The MAX6366LKA46+T has a factory-preset reset threshold of 4.63V (typical), with a guaranteed range of 4.50V to 4.75V over the full -40°C to +85°C operating temperature range. This value is laser-trimmed during production and does not require external resistor networks. The MAX6366LKA46+T uses this threshold to assert RESET whenever VCC falls below this level, ensuring reliable detection of +5V supply brownout conditions.

Does MAX6366LKA46+T support battery backup for SRAM during main power failure?

Yes, the MAX6366LKA46+T provides automatic battery backup for SRAM via its integrated switchover circuit. When VCC drops below both the 4.63V reset threshold and 20mV below VBATT, the device connects the BATT pin to the OUT pin to maintain power to external CMOS RAM. The MAX6366LKA46+T draws only 3µA from the backup source in this mode, enabling multi-year operation from standard coin cells.

What is the watchdog timeout period of MAX6366LKA46+T and how is it triggered?

The MAX6366LKA46+T features a 1.6s typical watchdog timeout period (range 1.00s to 2.25s). It is triggered when the WDI pin remains static-either high or low-for longer than this interval. Each rising or falling edge on WDI resets the timer, allowing firmware to "kick" the watchdog by toggling a GPIO. The MAX6366LKA46+T then asserts a pulse on the RESET output for the 150ms reset timeout period.

Can MAX6366LKA46+T be used with 3.3V microprocessors?

Yes, the MAX6366LKA46+T operates from 1.2V to 5.5V and guarantees RESET/RESET validity down to 1.2V, making it fully compatible with 3.3V µPs. Its 4.63V reset threshold monitors a +5V supply rail while its outputs interface safely with 3.3V logic levels. The open-drain RESET output can be pulled to 3.3V externally, and CE IN/CE OUT signals tolerate 3.3V logic swings without level shifters.

What package type and RoHS status does MAX6366LKA46+T use?

The MAX6366LKA46+T is supplied in an 8-pin SOT23 package (3.0mm × 1.7mm footprint, 1.3mm height) with lead(Pb)-free terminations, compliant with RoHS Directive 2011/65/EU. The "+T" suffix explicitly denotes lead-free tape-and-reel packaging, and the device meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) requirements for unlimited floor life at ≤30°C/60% RH.