Analog Devices Inc./Maxim Integrated MAX6365HKA29+

Overview

The MAX6365HKA29+ from Maxim Integrated is a low-power microprocessor supervisory circuit with battery backup, chip-enable gating, and manual reset input. It provides active-high open-drain reset output, factory-preset 2.93V reset threshold (±70mV), 150ms minimum reset timeout, and operates down to 1.2V supply voltage. It is used in portable equipment, POS terminals, and industrial controllers to ensure reliable µP startup and data retention during power failure.

For engineers reviewing the MAX6365HKA29+ datasheet, MAX6365HKA29+ pinout, MAX6365HKA29+ application, or MAX6365HKA29+ equivalent, key selection criteria include reset threshold accuracy, battery switchover hysteresis (40mV), CE gating propagation delay (1.5ns), quiescent current (10µA), and SOT23-8 package compatibility with space-constrained embedded designs.

Technical Context

This device integrates four core functions: precision VCC monitoring with brownout detection, automatic VCC-to-battery switchover when VCC falls below VBATT by >20mV, on-board chip-enable signal gating with 1.5ns propagation delay, and debounced manual reset input with internal 20kΩ pullup. Reset assertion is guaranteed down to 1.2V on either VCC or VBATT.

The MAX6365HKA29+ uses an internal MOSFET for battery switchover, delivering up to 150mA from VCC and supporting backup operation with <3µA battery standby current. Its CE IN/CE OUT transmission gate remains enabled only when reset is deasserted, preventing erroneous SRAM writes during power faults.

Key Specifications

Pinout & Package

MAX6365HKA29+ is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), optimized for high-density PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6365PKA29+, the MAX6365HKA29+ offers flexible reset polarity and external pull-up control; compared with TPS3808G33DBVR, it uniquely integrates battery switchover, CE gating, and manual reset - eliminating three discrete components in memory-critical systems.

Availability

MAX6365HKA29+ is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, and retail POS terminals requiring stable component supply across extended production lifecycles.

Supply support for MAX6365HKA29+ 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, sensing, and connectivity in demanding industrial and embedded environments.

The MAX6365–MAX6368 family targets space-constrained µP systems needing integrated power supervision, battery backup, and memory write protection - reducing BOM count and improving reliability over discrete solutions.

FAQ

What is the exact reset threshold voltage for MAX6365HKA29+?

The MAX6365HKA29+ has a factory-preset reset threshold of 2.93V (typical), with a guaranteed range of 2.85V to 3.00V across -40°C to +85°C. This value is laser-trimmed during production and does not require external resistor programming. The threshold remains stable over temperature, with typical drift of less than ±0.5% from -40°C to +85°C, ensuring consistent behavior in battery-powered and industrial environments where MAX6365HKA29+ is deployed.

Does MAX6365HKA29+ support battery backup for CMOS RAM, and how does switchover work?

Yes, MAX6365HKA29+ fully supports battery backup for CMOS RAM via its integrated VCC-to-BATT switchover circuit. When VCC drops below the reset threshold (2.93V) and falls 20mV below VBATT, the internal MOSFET connects BATT to OUT. Switchover hysteresis (40mV total) prevents oscillation during slow VCC decay. In backup mode, MAX6365HKA29+ draws only 3µA from the battery while sustaining SRAM power - a critical capability confirmed in the Electrical Characteristics table and Typical Operating Characteristics graphs.

What is the function of the CE IN and CE OUT pins on MAX6365HKA29+?

The CE IN and CE OUT pins implement hardware-enforced chip-enable gating to prevent SRAM corruption during power faults. When reset is deasserted, CE IN passes directly to CE OUT with 1.5ns propagation delay. When reset asserts, CE OUT is immediately disabled - if CE IN is low, CE OUT stays low for 12µs to complete ongoing memory access; if CE IN is high, CE OUT goes high. This behavior is explicitly defined in the Pin Description and Detailed Description sections for MAX6365HKA29+, and is independent of watchdog or battery functions.

Can MAX6365HKA29+ operate with a 1.2V supply, and what functions remain active?

Yes, MAX6365HKA29+ operates down to 1.2V on both VCC and VBATT supplies, with full functionality including reset assertion, CE gating, and MR input detection. The datasheet guarantees RESET/RESET validity, reset timeout period (tRP ≥ 150ms), and battery switchover operation at 1.2V. Quiescent current remains at 10µA, and battery standby current stays ≤3µA - making MAX6365HKA29+ suitable for ultra-low-power applications such as energy-harvesting sensors and wearables where MAX6365HKA29+ serves as the sole power supervisor.

Is the MR input on MAX6365HKA29+ debounced internally, and what is its electrical interface?

Yes, the MR input on MAX6365HKA29+ includes internal debouncing: it features a 20kΩ pullup resistor to VCC and 1µs minimum pulse-width rejection for noise immunity. MR accepts TTL/CMOS logic levels and is compatible with open-drain or open-collector drivers. A momentary switch from MR to GND suffices for manual reset - no external RC network is required. This is explicitly documented in the Pin Description and Applications Information sections, confirming that MAX6365HKA29+ eliminates external debounce components in cost-sensitive designs.