Analog Devices Inc./Maxim Integrated MAX25240AFFB/VY+

Overview

MAX25240AFFB/VY+ from Analog Devices is an automotive-grade synchronous buck-boost DC-DC converter with integrated H-bridge FETs, delivering up to 6A continuous output current across a 2V–36V input range while maintaining ±2% output regulation accuracy and operating from –40°C to +125°C. It supports fixed (5V/11.5V) or adjustable (3V–20V) output voltage, 2.1MHz/400kHz/200kHz switching frequencies, and features spread-spectrum EMI reduction for ADAS ECU and infotainment power rails.

For engineers reviewing the MAX25240AFFB/VY+ datasheet, MAX25240AFFB/VY+ pinout, MAX25240AFFB/VY+ application, or MAX25240AFFB/VY+ equivalent, key selection criteria include its AEC-Q100 Grade 1 qualification, 95μA standby quiescent current, 8.2A/10A selectable input current limit, thermally enhanced 22-pin FC2QFN package, and seamless buck/boost/buck-boost mode transitions without external control logic.

Technical Context

The MAX25240AFFB/VY+ implements peak-current-mode control with automatic transition between buck, boost, and buck-boost modes based on VIN/VOUT ratio-no external mode-select logic required. Its H-bridge architecture uses four internal DMOS switches (HS1/LS1/HS2/LS2), with minimum on-time of 100ns (2.1MHz) and programmable dead time, enabling stable operation down to 2V input during cold-crank.

It integrates a 1.8V VCC LDO regulator powered from SUP or OUT, a 2.5ms soft-start ramp, cycle-by-cycle current limiting with hiccup recovery, and open-drain PGOOD monitoring with 93%/94% rising/falling thresholds referenced to VOUT. The SYNC pin enables skip mode, forced PWM, or external clock synchronization with ±20% tolerance and two-cycle lock-in.

Key Specifications

Pinout & Package

MAX25240AFFB/VY+ is housed in a 4.25mm × 4.25mm × 0.75mm, 22-pin FC2QFN package with exposed thermal pad (F224A4FY+1 outline), optimized for high-power density and thermal performance in automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480-Q1 and TPS63802DRLR, the MAX25240AFFB/VY+ provides superior cold-crank support (2V min), higher output current (6A vs. 5A/2A), integrated H-bridge architecture eliminating external components, and AEC-Q100 Grade 1 qualification-making it the only choice for safety-critical automotive power rails requiring zero-layout compromise.

Availability

MAX25240AFFB/VY+ is available at Aetrix Electronics and suitable for ADAS ECU, infotainment systems, and start-stop systems requiring stable component supply across extended temperature and voltage ranges.

Supply support for MAX25240AFFB/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.

The MAX25239/MAX25240 product line delivers highly integrated, AEC-Q100-qualified buck-boost converters targeting next-generation automotive power architectures where cold-crank resilience, ultra-low quiescent current, and EMI-compliant operation are mandatory.

FAQ

What is the maximum continuous output current supported by the MAX25240AFFB/VY+?

The MAX25240AFFB/VY+ delivers up to 6A continuous output current depending on input-to-output voltage ratio, ambient temperature, and PCB thermal design. At 14V input and 5V output with 2.1MHz switching, full 6A is achievable with proper heatsinking; derating applies at extreme VIN/VOUT ratios or elevated temperatures per the Electrical Characteristics table.

Does the MAX25240AFFB/VY+ support both fixed and adjustable output voltages?

Yes, the MAX25240AFFB/VY+ supports fixed 5V or 11.5V outputs (by connecting FB to VCC) and adjustable outputs from 3V to 20V (by connecting FB to a resistor divider between OUT and AGND). The feedback reference voltage is tightly regulated at 0.800V ±1.75%, ensuring ±2% total output accuracy across temperature and line/load conditions.

How does the MAX25240AFFB/VY+ handle input voltage transients common in automotive systems?

The MAX25240AFFB/VY+ tolerates input transients up to 42V on SUP and EN pins, survives cold-crank down to 2V, and includes undervoltage lockout (4.2V rise, 1.9V fall) and overvoltage protection (108% of VOUT). Its integrated H-bridge and robust gate drivers ensure uninterrupted regulation during ISO 7637-2 pulse 5a/b load-dump events without external TVS clamping.

Can the MAX25240AFFB/VY+ be synchronized to an external clock, and what is the acceptable frequency range?

Yes, the MAX25240AFFB/VY+ accepts external synchronization via the SYNC pin. For the 2.1MHz variant, external clock must be 1.5MHz–2.7MHz; for the 400kHz variant, 280kHz–520kHz. The device locks to the external clock within two cycles and reverts to internal oscillator if SYNC is inactive for >2 cycles-ensuring deterministic timing in multi-rail synchronized systems.

What thermal performance can be expected from the MAX25240AFFB/VY+ in a standard 4-layer JEDEC board layout?

On a standard 4-layer JEDEC board, the MAX25240AFFB/VY+ exhibits a junction-to-ambient thermal resistance (θJA) of 33.3°C/W. With 6A output at 14V→5V conversion, typical power dissipation is ~1.8W, resulting in ~60°C junction rise above ambient-well within the +125°C Grade 1 rating. Using the EV kit's 4-layer board reduces θJA to 22.4°C/W for higher power margins.