Analog Devices Inc./Maxim Integrated MAX25240AFFA/VY+

Overview

MAX25240AFFA/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 and supporting fixed (5V/11.5V) or adjustable (3V–20V) output voltages. It operates in buck, boost, or buck-boost mode automatically based on VIN/VOUT ratio and features 2.1MHz/400kHz/200kHz selectable switching frequency, 95μA standby quiescent current, and AEC-Q100 Grade 1 qualification for ADAS ECU and start-stop systems.

For engineers reviewing the MAX25240AFFA/VY+ datasheet, MAX25240AFFA/VY+ pinout, MAX25240AFFA/VY+ application, or MAX25240AFFA/VY+ equivalent, key selection criteria include its 22-pin FC2QFN package, ±6% spread-spectrum EMI reduction, PGOOD monitoring, EN pin tolerance up to 42V, and thermal shutdown at 175°C - all critical for automotive power integrity and cold-crank reliability.

Technical Context

The MAX25240AFFA/VY+ implements peak-current-mode control with automatic transition between buck, boost, and buck-boost modes based on real-time VIN/VOUT ratio and internally preset 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 across input voltages below, above, or equal to the regulated output.

It integrates a 1.8V internal LDO (VCC) with 1.6V UVLO hysteresis, programmable soft-start (2.5ms), cycle-by-cycle current limiting (10A typical), and open-drain PGOOD with 93%/94% rising/falling thresholds referenced to VOUT. The SYNC pin supports skip mode, forced PWM, or external clock synchronization with ±20% frequency tolerance and two-cycle lock time.

Key Specifications

Pinout & Package

MAX25240AFFA/VY+ is housed in a thermally enhanced 4.25mm × 4.25mm × 0.75mm, 22-pin FC2QFN package with exposed thermal pad (pin 22 = AGND) and dual PGND planes (pins 5/6 and 9/10) for low-inductance high-current return paths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX25239AFFA/VY+ and LM61480-Q1, the MAX25240AFFA/VY+ uniquely combines 2.1MHz operation, ±6% spread spectrum, 42V-tolerant EN, and identical pinout to MAX25239 - enabling drop-in frequency upgrade without layout change while adding EMI mitigation for sensitive ADAS sensor rails.

Availability

MAX25240AFFA/VY+ is available at Aetrix Electronics and suitable for ADAS ECU, infotainment systems, and start-stop systems requiring stable component supply, automotive-grade traceability, and long-term lifecycle support.

Supply support for MAX25240AFFA/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 precision power, sensing, and connectivity solutions.

The MAX25240AFFA/VY+ belongs to Analog Devices' automotive power management portfolio, designed specifically for demanding vehicle subsystems requiring wide-input buck-boost regulation, AEC-Q100 compliance, and robust EMI performance in space-constrained ECUs.

FAQ

What is the maximum continuous output current supported by the MAX25240AFFA/VY+?

The MAX25240AFFA/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, it sustains 6A with proper heatsinking; derating applies above 125°C junction temperature per the thermal resistance specs (θJA = 33.3°C/W on JEDEC board).

Does the MAX25240AFFA/VY+ support both fixed and adjustable output voltages?

Yes, the MAX25240AFFA/VY+ supports fixed 5V or 11.5V outputs (by connecting FB to VCC) and externally adjustable outputs from 3V to 20V (using a resistor divider from OUT to AGND). The feedback reference voltage is tightly regulated at 0.800V ±1.75%, ensuring ±2% total output accuracy across line, load, and temperature.

How does the MAX25240AFFA/VY+ handle input voltage transients common in automotive environments?

The MAX25240AFFA/VY+ tolerates input transients up to 42V on both SUP and EN pins per ISO 7637-2 Pulse 5a, eliminating need for external TVS diodes in most 12V/24V systems. Its undervoltage lockout (4.2V rise, 1.9V fall) ensures clean startup during cold-crank events down to 2V, and the 175°C thermal shutdown protects against sustained overloads.

Can the MAX25240AFFA/VY+ be synchronized to an external clock, and what is the acceptable frequency range?

Yes, the MAX25240AFFA/VY+ accepts external clock signals on the SYNC pin with ±20% tolerance relative to its internal frequency (e.g., 1.68–2.52MHz for 2.1MHz variant). It achieves lock within two cycles and reverts to internal oscillator if external clock is absent for more than two periods - ensuring robust timing in multi-rail automotive systems.

What package type and thermal characteristics does the MAX25240AFFA/VY+ use?

The MAX25240AFFA/VY+ uses a 4.25mm × 4.25mm × 0.75mm, 22-pin FC2QFN package with exposed thermal pad (AGND). On a 4-layer JEDEC board, its junction-to-ambient thermal resistance is 33.3°C/W, and junction-to-board is 7.6°C/W - enabling efficient heat transfer to inner copper layers for high-power automotive applications.