Analog Devices Inc./Maxim Integrated MAX5085ATT+T

Overview

MAX5085ATT+T from Maxim Integrated is a high-voltage linear regulator delivering 3.3V fixed or adjustable 2.54V–11V output, supporting 6.5V–65V input, 200mA continuous load, and operating across –40°C to +125°C for automotive and industrial power rails. It features remote sensing (OUT_SENSE), 50μA no-load quiescent current, and thermal/short-circuit protection.

For engineers reviewing the MAX5085ATT+T datasheet, MAX5085ATT+T pinout, MAX5085ATT+T application, or MAX5085ATT+T equivalent, key selection criteria include its 6-pin TDFN package with exposed pad, Kelvin-sense capability for load regulation accuracy, low shutdown current (6μA typ), preset 3.3V output mode, and compatibility with high-input-voltage systems requiring stable low-noise bias supplies.

Technical Context

The MAX5085ATT+T implements a BiCMOS-based linear regulation architecture with internal 1.251V reference and error amplifier feedback loop. Its dual-mode operation-fixed 3.3V (SET = GND) or adjustable via resistive divider-enables flexible system-level voltage scaling without external op-amps.

Remote sensing is achieved through an internal 15Ω resistor between OUT and OUT_SENSE, allowing direct Kelvin connection to the load for sub-1% regulation error under trace resistance variation. The EN pin includes a 5MΩ internal pull-down, enabling direct connection to VIN for always-on operation or logic-level control with <1μA leakage.

Key Specifications

Pinout & Package

MAX5085ATT+T is housed in a thermally enhanced 3mm × 3mm, 6-pin TDFN-EP package with exposed paddle (EP) soldered to PCB ground for optimal heat dissipation (θJC = 8.5°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage linear regulator applications.

Compared with LM317LQDRG4Q1 and TPS7B8733QKVURQ1, MAX5085ATT+T uniquely combines 65V input tolerance, factory-trimmed 3.3V output, remote sensing, and sub-100μA quiescent current in a 3mm × 3mm package - making it the only single-chip solution for high-accuracy, high-voltage, low-power industrial and automotive bias rails.

Availability

MAX5085ATT+T is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, home security sensors, and telecom remote PHY units requiring stable component supply across extended temperature and high-input-voltage conditions.

Supply support for MAX5085ATT+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, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX5084/MAX5085 product line delivers high-voltage linear regulators optimized for harsh-environment systems needing reliable, low-quiescent-current bias supplies with remote sensing and wide input range - targeting automotive infotainment, industrial automation, and telecom infrastructure.

FAQ

What output voltage does MAX5085ATT+T deliver by default?

The MAX5085ATT+T delivers a factory-trimmed 3.3V output when the SET pin is connected to ground. This fixed-output mode requires no external resistors. If the SET pin is connected to a resistive divider between OUT and GND, the device operates in adjustable mode, supporting output voltages from 2.54V to 11V. The internal reference voltage is 1.251V, and output accuracy is ±2% over temperature and load for the 3.3V setting.

Can MAX5085ATT+T operate directly from a 48V telecom supply?

Yes, MAX5085ATT+T supports input voltages from 6.5V to 65V, making it fully compatible with standard 48V telecom distribution rails. At 48V input and 3.3V output delivering 200mA, power dissipation is approximately 9W - well within the 1.905W package limit at +70°C ambient when using proper PCB copper pour on the exposed pad. Derating applies above +70°C per the 23.8mW/°C thermal coefficient.

Does MAX5085ATT+T require an external capacitor on the OUT_SENSE pin?

No, MAX5085ATT+T does not require an external capacitor on the OUT_SENSE pin. The pin is internally connected to OUT via a 15Ω resistor and is intended for direct Kelvin connection to the load's power input node. If remote sensing is not needed, OUT_SENSE may be left floating or tied directly to OUT. Adding capacitance here is unnecessary and may degrade transient response or cause instability.

How is thermal performance affected by the exposed pad (EP) connection on MAX5085ATT+T?

The exposed pad (EP) on MAX5085ATT+T must be soldered to a solid GND plane to achieve specified thermal performance: θJC = 8.5°C/W and maximum power dissipation of 1.905W at +70°C. Without proper EP grounding, junction temperature rise increases significantly - potentially triggering thermal shutdown at much lower loads. JEDEC 51-compliant multilayer board layout with ≥4 thermal vias under the pad is recommended for production designs.

Is MAX5085ATT+T compatible with ceramic output capacitors?

Yes, MAX5085ATT+T is designed for stable operation with ceramic output capacitors ≥10μF and ESR < 0.5Ω. X7R or X5R dielectrics are preferred for full –40°C to +125°C operation; Z5U or Y5V types require ≥22μF to ensure stability below –10°C. A minimum 10μF ceramic capacitor is also required between IN and GND to suppress input transients and improve PSRR above 10kHz.