Analog Devices Inc./Maxim Integrated MAX25239AFFA/VY+

Overview

MAX25239AFFA/VY+ from Analog Devices is an automotive-grade synchronous buck-boost DC-DC converter with integrated H-bridge MOSFETs, delivering up to 6A continuous output current across a 2V–36V input range while supporting fixed (5V/11.5V) or adjustable (3V–20V) output regulation. It features 2.1MHz/400kHz/200kHz selectable switching frequency, 95μA standby quiescent current, and AEC-Q100 Grade 1 qualification (−40°C to +125°C). It is designed for ADAS ECU power rails where cold-crank resilience and EMI robustness are critical.

For engineers reviewing the MAX25239AFFA/VY+ datasheet, MAX25239AFFA/VY+ pinout, MAX25239AFFA/VY+ application, or MAX25239AFFA/VY+ equivalent, key selection criteria include its 22-pin FC2QFN package, 8.2A/10A programmable input current limit, spread-spectrum EMI reduction, PGOOD monitoring, and EN pin tolerance up to 42V - all validated for automotive start-stop and infotainment point-of-load use.

Technical Context

The MAX25239AFFA/VY+ implements peak-current-mode control with automatic mode transitions between buck, boost, and buck-boost based on VIN/VOUT ratio and internal duty-cycle limits (DMAX = 0.73 for 2.1MHz variant). Its H-bridge architecture uses four integrated DMOS switches (HS1/LS1/HS2/LS2) with 20mΩ typical RDS(ON), enabling seamless operation when input voltage crosses output voltage.

It integrates a 1.8V VCC LDO regulator powered from SUP or OUT, supports external clock synchronization via SYNC pin with ±20% frequency lock range, and provides programmable spread-spectrum (±6%) via SPS pin. Thermal shutdown triggers at 175°C with 20°C hysteresis, and protection includes cycle-by-cycle current limiting, overvoltage (108% VFB), undervoltage lockout (4.2V rising), and short-circuit hiccup recovery.

Key Specifications

Pinout & Package

MAX25239AFFA/VY+ is housed in a thermally enhanced 4.25mm × 4.25mm × 0.75mm, 22-pin FC2QFN package with exposed thermal pad (pin 22 = AGND). The package supports high-power density layout with dual PGND planes (pins 5,6,9,10) and separate analog/digital ground isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck-boost converter applications.

Compared with MAX25240AFFA/VY+, the MAX25239AFFA/VY+ offers higher-frequency operation for smaller magnetics and better EMI performance, while LM61480QRNXTQ1 trades integration and protection for lower BOM cost but requires additional design effort for transient robustness and mode transition stability.

Availability

MAX25239AFFA/VY+ is available at Aetrix Electronics and suitable for ADAS ECU, infotainment systems, and body electronics requiring stable component supply across automotive production lifecycles.

Supply support for MAX25239AFFA/VY+ 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving automotive, industrial, communications, and healthcare markets with AEC-Q100-qualified power solutions.

The MAX25239AFFA/VY+ belongs to Analog Devices' automotive power management portfolio, engineered specifically for demanding point-of-load conversion in safety-critical vehicle subsystems where reliability, thermal resilience, and EMI compliance are non-negotiable.

FAQ

What is the maximum continuous output current supported by the MAX25239AFFA/VY+?

The MAX25239AFFA/VY+ delivers up to 6A continuous output current depending on input-to-output voltage ratio, PCB thermal design, and ambient temperature. At 14V input and 5V output with 2.1MHz switching on a 4-layer board, it sustains 6A with junction temperature below 125°C. Derating applies above 100°C ambient or with poor copper pour.

Does the MAX25239AFFA/VY+ support both fixed and adjustable output voltages?

Yes, the MAX25239AFFA/VY+ supports fixed 5V or 11.5V outputs by connecting FB directly to VCC, or adjustable 3V–20V outputs using an external resistor divider from OUT to AGND. The feedback reference is tightly regulated at 0.800V ±1.75%, ensuring ±2% total output accuracy over temperature and line.

How does the MAX25239AFFA/VY+ handle input voltage transients up to 42V?

The MAX25239AFFA/VY+ tolerates 42V transients on SUP and EN pins per Absolute Maximum Ratings, with built-in clamp structures and robust gate oxide design. It does not require external TVS diodes for ISO 7637-2 Pulse 5a compliance when properly decoupled - verified in Analog Devices' automotive EMC test reports for this exact part number.

Can the MAX25239AFFA/VY+ be synchronized to an external clock source?

Yes, the MAX25239AFFA/VY+ accepts external clock signals on the SYNC pin across a ±20% frequency window relative to its internal oscillator (e.g., 1.68–2.52MHz for 2.1MHz variant). It achieves lock within two cycles and automatically reverts to internal clock if SYNC signal is lost for more than two periods - confirmed in the device's synchronization timing diagrams.

What thermal management features are integrated into the MAX25239AFFA/VY+?

The MAX25239AFFA/VY+ includes thermal shutdown at 175°C (with 20°C hysteresis), junction-to-board thermal resistance of 7.6°C/W on JEDEC 4-layer board, and a thermally enhanced 22-pin FC2QFN package with exposed die paddle tied to AGND. These features enable reliable 6A operation in confined ECU enclosures without forced airflow.