Analog Devices Inc./Maxim Integrated MAX6365PKA31

Overview

The MAX6365PKA31 from Maxim Integrated is a low-power microprocessor supervisory circuit with battery-backup switching, chip-enable gating, and a debounced manual reset input. It operates from 1.2V to 5.5V, features a factory-preset 3.08V reset threshold (±70mV), guarantees RESET assertion down to 1.2V, delivers 150ms minimum reset timeout, and supports CMOS RAM backup in brownout conditions.

For engineers reviewing the MAX6365PKA31 datasheet, MAX6365PKA31 pinout, MAX6365PKA31 application, or MAX6365PKA31 equivalent, this device serves as a precision power-monitoring and memory-protection solution for portable, industrial, and embedded µP systems requiring reliable VCC supervision, seamless battery switchover, and write-protection during supply faults.

Technical Context

The MAX6365PKA31 integrates four core functions: (1) precise VCC monitoring with ±0.07V threshold accuracy over temperature; (2) automatic VCC-to-battery switchover when VCC falls below both VTH and VBATT by ≥20mV; (3) chip-enable signal gating with 1.5ns propagation delay and 20–100Ω on-resistance; and (4) debounced manual reset with 20kΩ internal pullup and 120ns MR-to-RESET delay.

It uses an internal MOSFET switch for battery backup, maintains CE OUT high during reset if CE IN was high, holds CE OUT low for 12µs if CE IN was low at reset assertion, and guarantees valid RESET/RESET operation down to 1.2V supply-enabling robust operation in ultra-low-voltage µP systems.

Key Specifications

Pinout & Package

MAX6365PKA31 is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable and industrial PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6365LKA31, the MAX6365PKA31 offers superior noise immunity via open-drain RESET with configurable pullup, while TPS3808G33 trades integrated functionality for lower quiescent current and simpler implementation-making each suitable for distinct subsystem roles in tiered power management architectures.

Availability

MAX6365PKA31 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, POS terminal memory protection, and smart energy meter RTC backup requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6365PKA31 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 industrial, automotive, and medical applications.

The MAX6365–MAX6368 product line delivers integrated µP supervision with battery backup and chip-enable gating-engineered specifically for systems requiring zero-data-loss memory retention, ultra-low-power operation, and robust brownout recovery in space- and power-constrained environments.

FAQ

What is the exact reset threshold voltage of the MAX6365PKA31?

The MAX6365PKA31 has a factory-preset reset threshold of 3.08V (typical), with a guaranteed range of 3.00V to 3.15V across −40°C to +85°C. This value is laser-trimmed during production and applies specifically to the "KA31" suffix variant, making it ideal for monitoring +3.3V power rails with built-in margin against noise and temperature drift.

Does the MAX6365PKA31 support battery backup for CMOS RAM?

Yes, the MAX6365PKA31 supports battery backup for CMOS RAM through its integrated VCC-to-BATT switchover circuit. When VCC drops below both the 3.08V reset threshold and VBATT by at least 20mV, the device automatically connects the backup battery to the OUT pin, sustaining SRAM operation with <3µA quiescent drain-enabling multi-year data retention on coin cells.

What type of reset output does the MAX6365PKA31 provide?

The MAX6365PKA31 provides an active-high open-drain RESET output (pin 1). It requires an external pullup resistor to define the high-state voltage level. This configuration allows flexible interfacing with diverse µP reset inputs, supports wired-OR reset bus architectures, and improves noise immunity compared to push-pull outputs in electrically noisy environments.

How does the manual reset (MR) input function on the MAX6365PKA31?

The MR input on the MAX6365PKA31 is an active-low, debounced manual reset pin with a 20kΩ internal pullup to VCC. Driving MR low asserts RESET high continuously; RESET remains asserted for at least 150ms after MR returns high. No external debounce circuitry is needed, and the pin accepts TTL/CMOS logic levels or open-drain signals.

Can the MAX6365PKA31 gate chip-enable signals for SRAM during power faults?

Yes, the MAX6365PKA31 provides dedicated chip-enable gating via CE IN (pin 2) and CE OUT (pin 8). During normal operation, CE IN passes directly to CE OUT with 1.5ns propagation delay. When reset asserts, CE OUT is disabled-preventing spurious writes to SRAM. If CE IN is low at reset assertion, CE OUT stays low for 12µs to complete ongoing memory access.