Analog Devices Inc./Maxim Integrated MAX6367PKA26+

Overview

MAX6367PKA26+ from Maxim Integrated is a battery-backup supervisory circuit with BATT ON indicator output, precision 2.63V reset threshold, open-drain active-low RESET, and chip-enable gating for CMOS RAM protection. It operates from 1.2V to 5.5V, delivers ≤10µA quiescent current, and supports automatic VCC-to-battery switchover in brownout conditions for real-time clock and SRAM backup.

For engineers reviewing the MAX6367PKA26+ datasheet, MAX6367PKA26+ pinout, MAX6367PKA26+ application, or MAX6367PKA26+ equivalent, key selection criteria include its guaranteed 2.63V ±70mV reset threshold, 150ms min reset timeout, BATT ON push-pull high-indicator function, CE IN/CE OUT 1.5ns propagation delay, and SOT23-8 package compatibility with space-constrained µP systems.

Technical Context

The MAX6367PKA26+ implements a dual-supply monitoring architecture where VCC falling below 2.63V triggers continuous active-low RESET assertion and initiates automatic switchover to BATT when VCC drops 20mV below VBATT. Its internal MOSFET switch connects BATT to OUT with on-resistance as low as 4.6Ω at 2.38V/25mA.

BATT ON functions as a dedicated push-pull output that drives high only during battery-backup mode (VCC < VTH and VCC < VBATT), sinking 3.2mA at 0.4V saturation. CE IN/CE OUT transmission gate provides 20–100Ω on-resistance and 12µs reset-to-CE OUT delay to prevent erroneous memory writes during power faults.

Key Specifications

Pinout & Package

MAX6367PKA26+ is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm) with gull-wing leads, RoHS-compliant lead-free finish (+ suffix), and thermal pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6367HKA26+, the MAX6367PKA26+ offers open-drain RESET for flexible bus interfacing but requires a pull-up; compared with TPS3808G125DBVR, it integrates battery switchover and CE gating-reducing PCB area by 22mm² and eliminating 4 passive components.

Availability

MAX6367PKA26+ is available at Aetrix Electronics and suitable for real-time clock backup, SRAM data retention, POS terminal power fail, and set-top box firmware protection requiring stable component supply across industrial temperature range (-40°C to +85°C).

Supply support for MAX6367PKA26+ 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 interface applications in industrial, computing, and communications markets.

The MAX6365–MAX6368 family targets µP-based systems needing integrated power supervision, battery switchover, and memory write protection in ultra-small form factors.

FAQ

What is the exact reset threshold voltage of MAX6367PKA26+ and how tightly is it specified?

The MAX6367PKA26+ has a factory-trimmed reset threshold of 2.63V, with guaranteed limits of 2.55V (min) and 2.70V (max) over the full -40°C to +85°C temperature range. This 150mV total tolerance ensures reliable detection of 2.5V supply brownout without false triggering, and is confirmed in the Electrical Characteristics table under "Reset Threshold VTH".

Does MAX6367PKA26+ support true battery-backup operation with zero current draw from the backup source when VCC is present?

Yes. When VCC is above the reset threshold and exceeds VBATT by more than 20mV, MAX6367PKA26+ isolates BATT completely-drawing only -1.0µA to +0.05µA standby current from the battery (IBATT specification). This near-zero drain enables decade-long shelf life for lithium primary cells used in metering and security applications.

How does the BATT ON output behave during power transitions, and what load can it drive?

The BATT ON output of MAX6367PKA26+ is a push-pull driver that goes high only when both VCC < VTH and VCC < VBATT (i.e., true battery-backup mode). It sinks 3.2mA at 0.4V saturation and can directly drive LEDs, optocouplers, or base/gate electrodes of external P-MOSFETs-eliminating need for level-shifting or buffering circuitry.

Can MAX6367PKA26+ be used without a backup battery, and if so, how should BATT and OUT pins be connected?

Yes. For non-battery applications, connect BATT to GND and tie OUT directly to VCC. In this configuration, MAX6367PKA26+ functions solely as a reset supervisor with BATT ON permanently low and CE gating still fully operational-preserving memory write protection during VCC brownout without requiring hardware changes.

What is the propagation delay from CE IN to CE OUT, and why is it critical for memory interface timing?

The CE IN to CE OUT propagation delay of MAX6367PKA26+ is 1.5ns typical (50Ω source, 50pF load), enabling safe use with µPs running at ≥50MHz. This sub-nanosecond delay ensures CE gating occurs synchronously with address strobes, preventing partial writes to SRAM during power faults-verified in the Typical Operating Characteristics graph "CE IN to CE OUT Propagation Delay vs. Load Capacitance".