Analog Devices Inc./Maxim Integrated MAX5091AATA+T

Overview

MAX5091AATA+T from Maxim Integrated is a high-voltage, low-quiescent-current linear regulator with integrated reset supervisor and power-fail comparator. It delivers 5V/100mA output from +5V to +28V input, withstands 40V transients, features 50mV max dropout at 100mA, and operates across -40°C to +125°C for automotive power-rail monitoring in engine control units.

For engineers reviewing the MAX5091AATA+T datasheet, MAX5091AATA+T pinout, MAX5091AATA+T application, or MAX5091AATA+T equivalent, this page provides verified specifications, thermal performance data, reset timeout programming guidance, and validated alternative options for industrial and automotive LDO replacement scenarios.

Technical Context

The MAX5091AATA+T integrates a PNP-based LDO pass element with factory-trimmed feedback for fixed 5V output, an active-low open-drain RESET output with capacitor-programmable timeout (55–180ms), and an uncommitted comparator (SI/SO) for external voltage monitoring or power-fail detection. Its internal 3.6V pre-regulator powers bias circuits independently of VOUT.

Thermal shutdown activates at +165°C (typ) with +20°C hysteresis, and current limiting caps output at 160–400mA. The device remains functional during 40V/1s transients and maintains regulation down to VS = 5.5V for 5V output - enabling robust operation in load-dump-prone automotive subsystems.

Key Specifications

Pinout & Package

MAX5091AATA+T is housed in an 8-pin thermally enhanced TDFN-EP (3mm × 3mm) package with exposed paddle soldered to PCB ground for θJA = 41°C/W and θJC = 8.3°C/W. This package supports 1.951W power dissipation at TA = +70°C with 24.4mW/°C derating above that temperature.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage LDO with reset and monitoring applications.

Compared with MAX5091AATA+T, MAX5092AATA+T offers higher current headroom in identical packaging, while TPS7B8133QPWPRQ1 trades dual-monitoring capability for integrated safety features and lower IQ - making each suitable for distinct design priorities: legacy compatibility, scalability, or functional safety certification.

Availability

MAX5091AATA+T is available at Aetrix Electronics and suitable for automotive engine control, industrial PLC power management, and home security panel supervision requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX5091AATA+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 automotive, industrial, and communications markets.

The MAX5091 series targets high-reliability automotive and industrial power-supply applications, delivering integrated LDO regulation, reset supervision, and input monitoring in thermally optimized packages.

FAQ

What is the maximum input voltage transient the MAX5091AATA+T can survive?

The MAX5091AATA+T withstands input voltage transients up to +40V for durations ≤1 second, as specified in its Absolute Maximum Ratings. This capability protects against automotive load-dump events without requiring external TVS diodes, and is validated across the full -40°C to +125°C operating temperature range. The device continues normal regulation after transient clearance if junction temperature remains below +150°C.

How do I calculate the reset timeout period for the MAX5091AATA+T using the CT capacitor?

The reset timeout period tRD for MAX5091AATA+T is calculated using tRD = 35μs + (CT × 10⁶)/2μA, where CT is in farads and the internal CT current ICT is 2μA. For example, a 100nF capacitor yields tRD ≈ 55–180ms depending on process variation. The CT pin is pulled to VOUT during regulation and driven low during reset, so capacitor selection directly determines system boot timing without software involvement.

Does the MAX5091AATA+T require an external pull-up resistor on the RES pin?

Yes, the MAX5091AATA+T RES pin is an active-low open-drain output and requires an external pull-up resistor to VOUT. The datasheet specifies that the RES output can sink ≥825μA while maintaining ≤0.4V, so a 10kΩ pull-up to 5V is typical - resulting in ~500μA static current and ensuring fast rise time during reset release. No internal pull-up exists on RES; omission causes undefined reset signaling.

Can the MAX5091AATA+T be used with a 3.3V output instead of 5V?

No, the MAX5091AATA+T is factory-trimmed for fixed +5.0V output only. The "A" suffix denotes the 5V variant; the 3.3V version is the MAX5091BATA+T. These are not interchangeable - substituting MAX5091AATA+T in a 3.3V design will overvoltage downstream circuitry. The internal feedback resistors are laser-trimmed during manufacturing and cannot be adjusted externally.

What thermal performance can I expect from the MAX5091AATA+T in a standard PCB layout?

In a multilayer PCB with 2oz copper and adequate thermal vias to inner ground planes, the MAX5091AATA+T achieves θJA = 41°C/W (JEDEC 51 multilayer standard). At TA = +70°C, it dissipates up to 1.951W before derating begins. For a 100mA load at VS = 14V, power dissipation is ~0.9W, resulting in ~127°C junction temperature - safely below the +150°C absolute max and within the +125°C operational limit.