Analog Devices Inc./Maxim Integrated MAX6365LKA44+

Overview

MAX6365LKA44+ from Maxim Integrated is a low-power microprocessor supervisory circuit with battery backup switching, chip-enable gating, and factory-preset 4.38V reset threshold. It provides active-low push-pull RESET output, monitors VCC down to 1.2V, delivers ≤15µA supply current at +25°C, and supports CMOS RAM write protection in brownout conditions - used in portable POS terminals and industrial controllers requiring reliable power-fail response.

For engineers reviewing the MAX6365LKA44+ datasheet, MAX6365LKA44+ pinout, MAX6365LKA44+ application, or MAX6365LKA44+ equivalent, key selection criteria include its 4.38V reset threshold tolerance (±0.13V), 150ms minimum reset timeout, 1.5ns CE propagation delay, guaranteed RESET assertion down to 1.2V VCC/VBATT, and SOT23-8 package compatibility with space-constrained µP systems.

Technical Context

The MAX6365LKA44+ integrates a precision voltage monitor, debounced manual reset input (MR), bidirectional VCC/BATT switchover MOSFET, and series transmission-gate CE path. Its internal 20kΩ MR pullup enables direct switch-to-GND connection without external components, while the CE IN–CE OUT path maintains <2ns propagation delay under 50Ω/50pF load conditions.

Reset assertion occurs when VCC falls below 4.38V (min 4.25V, max 4.50V), MR is pulled low, or during power-up/brownout; RESET remains asserted for ≥150ms after VCC recovers. In battery-backup mode, OUT connects to BATT only when VCC < VTH and VCC < (VBATT − 20mV), with 40mV hysteresis preventing oscillation during slow VCC decay.

Key Specifications

Pinout & Package

MAX6365LKA44+ is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), optimized for PCB area-constrained applications including handheld instrumentation and embedded controllers.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6365PKA44+, the MAX6365LKA44+ uses leaded packaging and has top mark AA AI, making it suitable for legacy reflow processes; versus TPS3808G33DBVR, it adds critical battery switchover and CE gating - essential for data retention in power-loss scenarios.

Availability

MAX6365LKA44+ is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLCs, smart energy meters, and retail POS terminals requiring stable component supply across extended production lifecycles.

Supply support for MAX6365LKA44+ 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 interface applications in industrial, automotive, and communications markets.

The MAX6365–MAX6368 family targets space- and power-constrained microprocessor systems needing integrated reset, battery backup, and memory write protection - eliminating discrete diodes, MOSFETs, and logic gates.

FAQ

What is the exact reset threshold voltage for MAX6365LKA44+?

The MAX6365LKA44+ features a factory-trimmed reset threshold of 4.38V (typical), with a guaranteed range of 4.25V to 4.50V across −40°C to +85°C. This value is laser-trimmed during production and documented in the Reset Threshold Ranges table of the datasheet. The "44" suffix in MAX6365LKA44+ explicitly denotes this 4.38V threshold variant, and the parameter is validated per unit during 100% production testing at +25°C.

Does MAX6365LKA44+ support battery backup for CMOS RAM?

Yes, MAX6365LKA44+ provides fully integrated battery backup for CMOS RAM. When VCC drops below 4.38V and falls 20mV below VBATT, the internal MOSFET automatically connects the BATT pin to the OUT pin, supplying up to 40mA to preserve SRAM contents. The device draws only 3µA from the battery in backup mode, enabling multi-year operation on standard coin cells - confirmed in Electrical Characteristics Table and Typical Operating Characteristics Figure MAX6365/8-02.

What is the function of the CE IN and CE OUT pins on MAX6365LKA44+?

CE IN and CE OUT implement hardware-enforced chip-enable gating: CE IN connects to the µP's chip-select signal, and CE OUT drives the SRAM's CE pin. During normal operation, the path is transparent (1.5ns delay). When reset asserts, CE OUT is immediately disabled - holding low for 12µs to complete ongoing memory access, then floating high. This prevents corrupted writes during power transitions, a feature unique to the MAX6365–MAX6368 family and verified in the Detailed Description section.

Can MAX6365LKA44+ operate with a 1.2V supply?

Yes, MAX6365LKA44+ operates from VCC as low as 1.2V, and its RESET output remains valid (guaranteed logic low/high) down to 1.2V on either VCC or VBATT. This capability is specified in the Absolute Maximum Ratings and Electrical Characteristics tables, enabling use in ultra-low-power microcontrollers and energy-harvesting systems where supply rails dip below 1.8V during sleep modes.

Is the MR pin on MAX6365LKA44+ debounced internally?

Yes, the MR (manual reset) input on MAX6365LKA44+ includes integrated hardware debounce, eliminating the need for external RC filters. The internal 20kΩ pullup to VCC allows direct connection of a momentary switch from MR to GND. Debounce timing is inherent to the digital reset generator architecture and ensures clean reset assertion even with mechanical switch bounce - detailed in the Manual Reset Input section and confirmed in Pin Description Table.