Analog Devices Inc./Maxim Integrated MAX6365LKA29-T

Overview

The MAX6365LKA29-T from Maxim Integrated is a low-power microprocessor supervisory circuit with battery backup, chip-enable gating, and debounced manual reset input. It monitors VCC supply voltage (reset threshold 2.85V–3.00V), provides active-low open-drain RESET output, switches VCC/BATT to OUT with <4.6Ω on-resistance, and operates down to +1.2V supply. It is used in portable equipment requiring reliable power-fail detection and SRAM data retention during brownout.

For engineers reviewing the MAX6365LKA29-T datasheet, MAX6365LKA29-T pinout, MAX6365LKA29-T application, or MAX6365LKA29-T equivalent, key selection criteria include its 2.93V typical reset threshold, 150ms minimum reset timeout, 10µA quiescent current, SOT23-8 package, and integrated CE signal gating with 1.5ns propagation delay.

Technical Context

This device implements a precision voltage monitor with factory-trimmed 2.93V reset threshold (±7mV over temperature), a dedicated manual reset input (MR) with internal 20kΩ pullup and 120ns MR-to-RESET delay, and a bidirectional VCC/BATT switchover path controlled by a low-on-resistance MOSFET switch. The chip-enable gating function uses a transmission gate with 20–100Ω on-resistance and 1.5ns propagation delay, enabling direct interface with high-speed µP CE lines.

It operates across -40°C to +85°C, guarantees RESET assertion down to 1.2V VCC or VBATT, and features 150ms min reset timeout with immunity to transients ≤30µs at 100mV overdrive. The open-drain RESET output supports flexible pullup configurations and remains valid during battery-backup mode.

Key Specifications

Pinout & Package

MAX6365LKA29-T is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained portable designs. Pin numbering follows standard SOT23 top-view orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6365PKA29-T, the MAX6365LKA29-T offers open-drain active-high RESET for flexible level-shifting and pullup configuration, while TPS3808G33DBVR omits critical battery-switchover and CE gating functions required for SRAM data retention in portable systems.

Availability

MAX6365LKA29-T is available at Aetrix Electronics and suitable for portable medical monitors, industrial data loggers, retail point-of-sale terminals, and set-top box firmware recovery systems requiring stable component supply and long-term lifecycle support.

Supply support for MAX6365LKA29-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 industrial, automotive, and computing applications.

The MAX6365 series belongs to Maxim's µP supervisory product line, engineered specifically for systems requiring coordinated power monitoring, battery-backed memory retention, and hardware-enforced write protection during supply faults.

FAQ

What is the exact reset threshold voltage of the MAX6365LKA29-T?

The MAX6365LKA29-T has a factory-trimmed reset threshold range of 2.85V to 3.00V, with a typical value of 2.93V at +25°C. This threshold is guaranteed over the full operating temperature range (-40°C to +85°C) and exhibits ±7mV variation across temperature, ensuring consistent brownout detection for 3.3V systems without requiring external calibration. The MAX6365LKA29-T datasheet specifies this value in the Reset Threshold table under Ordering Information suffix "29".

Does the MAX6365LKA29-T support battery backup for SRAM, and how does it switch?

Yes, the MAX6365LKA29-T supports battery backup for SRAM via its integrated VCC/BATT switchover circuit. When VCC falls below the reset threshold and also drops 20mV below VBATT, the internal MOSFET connects BATT to OUT, powering SRAM from the backup source. The 40mV hysteresis prevents oscillation during slow VCC decay. The MAX6365LKA29-T guarantees this function operates down to 1.2V VBATT and draws only 3µA in backup mode, enabling multi-year coin-cell operation.

What is the function of the CE IN and CE OUT pins on the MAX6365LKA29-T?

The CE IN and CE OUT pins on the MAX6365LKA29-T implement hardware-enforced chip-enable gating to prevent SRAM corruption during power faults. During normal operation, CE IN passes directly to CE OUT with 1.5ns propagation delay and 20–100Ω on-resistance. When reset asserts, CE OUT is held low for 12µs to complete ongoing memory access, then disconnected and actively pulled up to OUT. This ensures no spurious writes occur to CMOS RAM during brownout-critical for the MAX6365LKA29-T's role in data-critical portable systems.

What type of reset output does the MAX6365LKA29-T provide, and how is it configured?

The MAX6365LKA29-T provides an active-high open-drain RESET output (Pin 1). It asserts high continuously when VCC falls below 2.93V, when MR is pulled low, or during fault conditions, and remains asserted for ≥150ms after VCC recovers. Because it is open-drain, the MAX6365LKA29-T requires an external pullup resistor to the appropriate logic rail (e.g., VCC or another supply) to establish the inactive-state voltage level-enabling level-shifting and compatibility with diverse µP reset input requirements.

Can the MAX6365LKA29-T operate from a 1.8V main supply, and what is its minimum operating voltage?

Yes, the MAX6365LKA29-T fully supports 1.8V main supply operation and operates down to +1.2V on either VCC or VBATT. Its supply current remains stable (10–50µA) across 1.2V–5.5V, and both RESET assertion and release are guaranteed functional at 1.2V. This makes the MAX6365LKA29-T suitable for modern low-voltage systems including those powered by single-cell Li-ion (2.7–4.2V) or regulated 1.8V rails, where brownout detection must remain active even during deep voltage sags.