Analog Devices Inc./Maxim Integrated MAX6367LKA31+T

Overview

The MAX6367LKA31+T from Maxim Integrated is a low-power microprocessor supervisory circuit with battery-backup control and chip-enable gating, featuring a factory-preset 3.08V reset threshold, active-high BATT ON output, and operation down to 1.2V supply voltage. It monitors VCC for power-up/down/brownout, switches OUT between VCC and backup battery (VBATT), gates CE signals with 1.5ns propagation delay, and asserts reset for ≥150ms after VCC recovery - used in portable POS terminals and industrial controllers requiring nonvolatile memory retention during main supply failure.

For engineers reviewing the MAX6367LKA31+T datasheet, MAX6367LKA31+T pinout, MAX6367LKA31+T application, or MAX6367LKA31+T equivalent, key selection criteria include its 3.08V reset threshold accuracy, BATT ON push-pull indicator function, SOT23-8 package compatibility, and guaranteed reset assertion down to 1.2V VCC or VBATT.

Technical Context

The MAX6367LKA31+T implements a precision voltage monitor with ±1.5% reset threshold tolerance over temperature, integrated MOSFET-based VCC/BATT switchover with 40mV hysteresis, and a dedicated push-pull BATT ON output that drives high only when VCC falls below VTH and VBATT exceeds VCC by ≥20mV. Its chip-enable gating uses a transmission gate with 20Ω–100Ω on-resistance and 12µs reset-to-CE OUT delay to prevent SRAM corruption during fault conditions.

Unlike the MAX6365 (MR input) or MAX6366 (watchdog), the MAX6367LKA31+T provides no manual reset or watchdog functionality but adds BATT ON status indication - a fixed-function variant within the MAX6365–MAX6368 family sharing identical pinout, SOT23-8 packaging, and core supervision architecture.

Key Specifications

Pinout & Package

Package: 8-pin SOT23, 2.9mm × 1.6mm × 1.1mm body, lead(Pb)-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6367PKA31+T, the MAX6367LKA31+T offers open-drain RESET for flexible voltage-level translation, while MAX6367HKA31+T adds automotive qualification - all share identical BATT ON behavior, 3.08V threshold, and SOT23-8 footprint.

Availability

MAX6367LKA31+T is available at Aetrix Electronics and suitable for portable POS terminals, industrial programmable logic controllers, medical patient monitors, and smart energy meters requiring stable component supply across long production lifecycles.

Supply support for MAX6367LKA31+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, sensing, and connectivity applications in industrial, medical, and communications markets.

The MAX6365–MAX6368 product line delivers ultra-low-power supervisory functions with integrated battery switchover and memory write protection, targeting space-constrained embedded systems needing reliable power-fail response without external discretes.

FAQ

What is the exact reset threshold voltage of the MAX6367LKA31+T?

The MAX6367LKA31+T has a factory-trimmed reset threshold of 3.00V (min), 3.08V (typ), and 3.15V (max) over temperature. This 3.08V nominal value is optimized for reliable detection of brownout conditions in 3.3V microprocessor systems while maintaining margin against noise-induced false triggers. The MAX6367LKA31+T achieves this accuracy using laser-trimmed internal resistors, with ±1.5% tolerance guaranteed across -40°C to +85°C.

Does the MAX6367LKA31+T provide manual reset or watchdog functionality?

No, the MAX6367LKA31+T does not include manual reset (MR) or watchdog timer (WDI) inputs. It is the BATT ON variant of the MAX6365–MAX6368 family, dedicated solely to battery-status indication and power supervision. The MAX6365LKA31+T provides MR, the MAX6366LKA31+T provides WDI, and the MAX6368LKA31+T provides adjustable RESET IN - all sharing the same SOT23-8 pinout but differing in functional pins 1 and 4.

How does the BATT ON output behave in the MAX6367LKA31+T?

The BATT ON output of the MAX6367LKA31+T is a push-pull driver that goes high only when two conditions are simultaneously met: VCC has fallen below the 3.08V reset threshold, and VBATT exceeds VCC by at least 20mV. It remains high throughout battery-backup mode and returns low within 12µs of VCC rising above VTH. This precise dual-condition logic prevents false assertions during transient dips or insufficient backup voltage.

What is the maximum load current supported by the OUT pin of the MAX6367LKA31+T?

The OUT pin of the MAX6367LKA31+T delivers up to 150mA from VCC under normal operation, with VCC-to-OUT on-resistance as low as 3.1Ω at 4.75V. In battery-backup mode, it sources from VBATT with on-resistance dependent on battery voltage - e.g., 4.6Ω at VBATT = 2.38V and 25mA load. The device includes short-circuit protection on OUT, limiting fault current to prevent thermal damage during sustained overload.

Can the MAX6367LKA31+T operate with a 1.2V supply voltage?

Yes, the MAX6367LKA31+T operates with VCC or VBATT as low as 1.2V, and its RESET and BATT ON outputs remain fully functional down to this voltage. The reset comparator, BATT ON driver, and chip-enable gating circuits are all specified to operate correctly at 1.2V, enabling use with single-cell lithium or NiMH batteries without voltage boosting. Quiescent current stays below 50µA at 1.2V, supporting multi-year operation on small backup cells.