Analog Devices Inc./Maxim Integrated MAX6368PKA23+

Overview

MAX6368PKA23+ from Maxim Integrated is a low-power microprocessor supervisory circuit with auxiliary user-adjustable reset input, battery backup switchover, and chip-enable gating. It monitors VCC supply (1.2V–5.5V), asserts active-low open-drain RESET when VCC falls below 2.32V or RESET IN drops below 1.235V, provides 150ms minimum reset timeout, and supports CMOS RAM write protection in portable equipment and industrial controllers.

For engineers reviewing the MAX6368PKA23+ datasheet, MAX6368PKA23+ pinout, MAX6368PKA23+ application, or MAX6368PKA23+ equivalent, key selection criteria include its 1.235V auxiliary reset threshold accuracy, 10µA quiescent current, 8-pin SOT23 package, battery-switchover hysteresis, and CE IN/CE OUT propagation delay under 9ns - all critical for reliable power-fail response in space-constrained embedded systems.

Technical Context

The MAX6368PKA23+ integrates a precision 1.235V reference comparator for RESET IN, a VCC monitoring circuit with factory-trimmed 2.32V reset threshold (±0.06V over temperature), and a bidirectional transmission gate for chip-enable signal gating. Its battery switchover logic enforces dual conditions: VCC must be both below VTH and at least 20mV below VBATT before switching OUT to BATT.

RESET output is open-drain active-low, guaranteed functional down to 1.2V on either VCC or VBATT. CE IN to CE OUT path features 20Ω–100Ω on-resistance (reset not asserted) and 12µs reset-to-CE OUT hold time when CE IN is low during reset assertion - ensuring safe SRAM access termination during brownout.

Key Specifications

Pinout & Package

MAX6368PKA23+ is housed in an 8-pin SOT23 package (2.9mm × 1.6mm × 1.1mm), optimized for PCB area-constrained designs. The package supports reflow soldering per JEDEC J-STD-020, with lead(Pb)-free finish (RoHS-compliant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6367PKA23+, MAX6368PKA23+ trades BATT ON output for programmable RESET IN functionality - enabling dual-rail supervision without extra components. Versus TPS3808G125DBVR, it adds battery backup, CE gating, and adjustable reset input at higher quiescent current but delivers integrated system-level reliability unattainable with basic reset ICs.

Availability

MAX6368PKA23+ is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC controllers, smart energy meters, and retail POS terminals requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6368PKA23+ 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, automotive, and communications markets.

The MAX6365–MAX6368 family targets space-constrained µP systems needing integrated power monitoring, battery backup, and memory write protection - eliminating discrete diodes, MOSFETs, and comparators in compact embedded designs.

FAQ

What is the exact reset threshold voltage for MAX6368PKA23+?

The MAX6368PKA23+ has a factory-trimmed VCC reset threshold of 2.25V (min), 2.32V (typ), and 2.38V (max) at +25°C, with ±0.06V variation over -40°C to +85°C. This threshold applies to power-up, power-down, and brownout detection on the VCC pin. The device does not require external adjustment for this primary reset function.

How does the RESET IN pin on MAX6368PKA23+ function in practice?

The RESET IN pin on MAX6368PKA23+ compares an external voltage against an internal 1.235V reference. When the applied voltage falls below 1.185V (min), MAX6368PKA23+ asserts RESET. It is commonly used with a resistor divider to monitor secondary supplies - e.g., a 4.60V rail programmed using R1 = 273kΩ and R2 = 100kΩ as specified in the datasheet.

Can MAX6368PKA23+ operate with a 1.2V supply voltage?

Yes, MAX6368PKA23+ operates from VCC = 1.2V to 5.5V and guarantees RESET/RESET output functionality down to 1.2V on either VCC or VBATT. Its 10µA quiescent current and 3µA battery-backup current make it suitable for ultra-low-power systems powered by single-cell Li-ion or coin cells.

What is the purpose of the CE IN and CE OUT pins on MAX6368PKA23+?

The CE IN and CE OUT pins on MAX6368PKA23+ implement hardware-enforced chip-enable gating for SRAM or other memory devices. During normal operation, CE IN passes directly to CE OUT with <9ns delay. When RESET asserts, CE OUT is held low for 12µs if CE IN was low - preventing partial writes during power failure.

Does MAX6368PKA23+ support automatic switchover to backup battery?

Yes, MAX6368PKA23+ automatically switches the OUT pin from VCC to BATT when two conditions are met: VCC falls below the 2.32V reset threshold AND VCC is at least 20mV lower than VBATT. A 40mV hysteresis prevents oscillation during slow VCC decay, and the internal MOSFET delivers up to 150mA from VCC or 20mA from BATT.