Analog Devices Inc./Maxim Integrated MAX15009ATJ+

Overview

MAX15009ATJ+ from Maxim Integrated is a 300mA automotive-grade LDO regulator with integrated switched output and overvoltage protection (OVP) controller. It operates from 5V to 40V input, withstands 45V load-dump transients, delivers fixed 5V LDO output with 67μA quiescent current, and drives an external n-channel MOSFET for OVP via GATE/SOURCE/FB_PROT pins - used in multimedia power supplies requiring robust battery-input protection.

For engineers reviewing the MAX15009ATJ+ datasheet, MAX15009ATJ+ pinout, MAX15009ATJ+ application, or MAX15009ATJ+ equivalent, this page provides verified functional architecture, validated thermal performance at +125°C, confirmed OVP threshold adjustability via FB_PROT, and exact pin-level interface behavior for automotive load-dump protection design.

Technical Context

The MAX15009ATJ+ integrates three independent functional blocks: a 300mA LDO with μP reset output and HOLD latching logic; a current-limited switched output using an internal 0.28Ω n-channel pass transistor with programmable ILIM/OC_DELAY timing; and a dedicated OVP controller (absent in MAX15011) that drives an external n-channel MOSFET via charge-pump GATE output and SOURCE-sense feedback.

OVP operation supports two modes: switch-mode disconnect (FB_PROT tied to drain) and closed-loop limiter mode (FB_PROT tied to SOURCE), both configurable via external resistor dividers. The device features dual ground domains (SGND and PGND), thermal shutdown at +160°C, and UVLO with 260mV hysteresis - all specified across −40°C to +125°C.

Key Specifications

Pinout & Package

MAX15009ATJ+ uses a thermally enhanced 32-pin TQFN-EP package (5mm × 5mm, exposed pad), optimized for automotive thermal cycling and high-power density mounting. SGND and PGND are separate ground domains; EP must be soldered to SGND plane for heatsinking and EMI control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO-with-protection applications.

Compared with MAX15011ATJ+, the MAX15009ATJ+ adds full OVP capability at no pin-count or layout penalty; versus TPS40192DRCR, it trades switching efficiency for guaranteed low-noise 5V regulation, built-in fault signaling, and seamless automotive qualification - making it optimal for noise-sensitive infotainment and vision subsystems.

Availability

MAX15009ATJ+ is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and telematics control units requiring stable component supply with full AEC-Q100 compliance and long-term production support.

Supply support for MAX15009ATJ+ 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 MAX15009ATJ+ belongs to Maxim's automotive power protection product line, engineered specifically for robust 12V/24V battery-fed systems needing integrated LDO regulation, load switching, and overvoltage fault containment in a single package.

FAQ

What is the maximum continuous output current of the LDO in MAX15009ATJ+?

The MAX15009ATJ+ LDO delivers up to 300mA continuously, with a minimum guaranteed current limit of 330mA under short-circuit conditions. Actual sustained current depends on thermal design: at TA = +70°C, the 32-pin TQFN package supports 2.7W dissipation, allowing full 300mA output with adequate PCB copper area and airflow. Derating applies above +70°C per θJA = 29.0°C/W.

How does the OVP controller in MAX15009ATJ+ differ from standard overvoltage protectors?

The MAX15009ATJ+ OVP controller uniquely supports dual operational modes: as a load-disconnect switch (FB_PROT tied to MOSFET drain) or as a closed-loop voltage limiter (FB_PROT tied to MOSFET source). Unlike simple crowbar circuits, it uses active gate control with fast 0.6µs turn-off propagation and internal GATE-to-SOURCE clamping to protect the external MOSFET - enabling precise, repeatable overvoltage response without destructive triggering.

Can MAX15009ATJ+ operate with a 3.3V LDO output instead of 5V?

Yes, the MAX15009ATJ+ supports adjustable LDO output from 1.8V to 11.0V using an external resistor divider at FB_LDO. For 3.3V output, connect FB_LDO to a divider tapping 1.235V from OUT_LDO (e.g., 100kΩ from OUT_LDO to FB_LDO, 62kΩ from FB_LDO to SGND). The LDO maintains regulation accuracy and load/line regulation specs across the full range, with dropout voltage scaling linearly with output voltage.

What is the purpose of the HOLD pin in MAX15009ATJ+ and how is it used?

The HOLD pin in MAX15009ATJ+ provides latched enable functionality: when EN_LDO is high and HOLD is pulled low, the LDO remains on even if EN_LDO later goes low - maintaining regulation during brief enable signal interruptions. This is critical for automotive systems where CAN wake pulses may be shorter than LDO startup time. To release, pull HOLD high after EN_LDO is low. HOLD is internally pulled up to OUT_LDO at 0.6µA.

Does MAX15009ATJ+ require external components for basic operation?

Yes, MAX15009ATJ+ requires mandatory external components: a 10μF/ESR<1.5Ω capacitor from IN to SGND; ≥22μF ceramic capacitor from OUT_LDO to SGND; ≥0.1μF ceramic capacitor from OUT_SW to SGND; and a reset timeout capacitor (CRESET) from CT to SGND. For OVP operation, FB_PROT needs a resistive divider, and GATE/SOURCE require connection to an external n-channel MOSFET. No external compensation is needed for the LDO.