Analog Devices Inc./Maxim Integrated MAX6397LATA+T

Overview

The MAX6397LATA+T from Maxim Integrated is a high-voltage overvoltage protection controller with integrated 5V linear regulator, designed to safeguard downstream loads against transients up to 72V input. It controls an external n-channel MOSFET via a charge-pump-driven GATE output (up to VIN + 10V), supports adjustable overvoltage threshold (via SET pin), delivers 100mA regulated output, and features thermal shutdown and open-drain POK. It is used in industrial power rails and wall-cube adapters where robust transient immunity and always-on bias supply are required.

For engineers reviewing the MAX6397LATA+T datasheet, MAX6397LATA+T pinout, MAX6397LATA+T application, or MAX6397LATA+T equivalent, this device serves as a dual-function IC: overvoltage switch/limiter controller + low-quiescent (37µA) 5V linear regulator - critical for systems needing fault-tolerant input protection and persistent auxiliary power under wide VIN (5.5V–72V) and extended temperature (-40°C to +125°C) conditions.

Technical Context

The MAX6397LATA+T implements a precision voltage-monitoring loop using a 1.215V internal reference at the SET pin, with 5% hysteresis, enabling user-adjustable overvoltage thresholds via resistor dividers on IN or OUT. Its gate driver uses an internal charge pump delivering ≥75µA sourcing current to maintain ~10V gate-to-source enhancement for low-R_DS(ON) MOSFETs during normal operation.

In overvoltage-switch mode, it disconnects the load by pulling GATE to OUT within 0.75µs; in limiter mode, it generates a sawtooth GATE waveform to regulate V_OUT at the threshold. The integrated 5V linear regulator operates independently of SHDN and remains active even when the external FET is off, with POK asserting at 92.5% nominal output (L-grade).

Key Specifications

Pinout & Package

MAX6397LATA+T is housed in an 8-pin, 3mm × 3mm thermally enhanced TDFN-EP package with exposed pad (EP) requiring connection to GND for optimal thermal performance and EMI control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar overvoltage protection + bias regulator applications.

Compared with TPS26631RGER and LT4363IMS-2#PBF, the MAX6397LATA+T uniquely combines user-adjustable overvoltage protection, integrated 5V/100mA low-I_Q regulator, and POK in a single 3mm × 3mm package - reducing component count and enabling compact, self-contained protection for industrial and adapter-fed systems.

Availability

MAX6397LATA+T is available at Aetrix Electronics and suitable for industrial automation, wall-cube adapter interfaces, and notebook always-on rail designs requiring stable component supply across extended temperature and high-voltage operating conditions.

Supply support for MAX6397LATA+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6397LATA+T belongs to Maxim's overvoltage protection controller family, engineered to replace discrete MOSFET + comparator + charge pump solutions with a single IC that delivers both fault-tolerant input protection and persistent low-power bias regulation.

FAQ

What is the exact output voltage tolerance of the MAX6397LATA+T's integrated regulator?

The MAX6397LATA+T features a factory-trimmed 5.0V linear regulator with ±1.5% output tolerance over load (1mA–100mA) and temperature (-40°C to +125°C). At 25°C and 1mA load, the typical output is 5.00V, with min/max values of 4.925V and 5.120V respectively - confirmed in the Electrical Characteristics table under "REG Output Voltage (MAX6397L/M)".

Can the MAX6397LATA+T operate in overvoltage-limiter mode without an external MOSFET?

No. The MAX6397LATA+T is a controller IC and requires an external n-channel MOSFET to implement either overvoltage switch or limiter functionality. Its GATE output drives the MOSFET gate, and OUT senses the MOSFET source. Without the external FET, neither protection mode functions - the IC will power up and regulate 5V at REG, but cannot control load voltage or isolate faults.

What is the purpose of the exposed pad (EP) on the MAX6397LATA+T package?

The exposed pad (EP) on the MAX6397LATA+T's 8-pin TDFN package must be soldered to a GND-connected copper plane. It serves two critical roles: (1) thermal dissipation - lowering junction-to-board thermal resistance to sustain 1455mW continuous power at +70°C ambient; (2) noise reduction - providing low-inductance grounding for the internal charge pump and regulator, improving stability and EMI performance.

How does the POK output behave during shutdown (SHDN = low)?

During SHDN = low, the MAX6397LATA+T disables the GATE output to turn off the external MOSFET, but the REG output remains fully active and continues supplying 5V. Consequently, the POK output remains asserted (high-impedance, pulled up externally) as long as REG stays above 4.67V - confirming valid bias power is still present even when load isolation is active.

Is the MAX6397LATA+T compatible with 72V DC industrial buses?

Yes. The MAX6397LATA+T is explicitly rated for continuous operation from 5.5V to 72V input (VIN), with absolute maximum IN rating of +80V. Its internal charge pump, gate clamp (≤18V above OUT), and thermal shutdown ensure reliable function in 48V/60V/72V industrial systems - validated across -40°C to +125°C junction temperature per the Absolute Maximum Ratings and Operating Temperature Range specifications.