Analog Devices Inc./Maxim Integrated MAX25239AFFB/VY+T

Overview

MAX25239AFFB/VY+T 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 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 power rails.

For engineers reviewing the MAX25239AFFB/VY+T datasheet, MAX25239AFFB/VY+T pinout, MAX25239AFFB/VY+T application, or MAX25239AFFB/VY+T equivalent, key selection criteria include cold-crank operation down to 2V, 42V transient tolerance, 95μA standby quiescent current, AEC-Q100 Grade 1 qualification, and thermally enhanced 22-pin FC2QFN package with 4.25mm × 4.25mm footprint.

Technical Context

The MAX25239AFFB/VY+T implements peak-current-mode control across three operating modes-buck, boost, and buck-boost-dynamically transitioning based on VIN/VOUT ratio using internally preset duty-cycle limits (DMAX = 0.73 for 2.1MHz variant). Its H-bridge architecture integrates four power MOSFETs (HS1/LS1/HS2/LS2) with 20mΩ typical RDSON, enabling seamless mode transitions without external control logic.

It features a 1.8V internal LDO (VCC) with 4.7μF bypassing, programmable soft-start (2.5ms), cycle-by-cycle current limiting (8.2A/10A options), open-drain PGOOD with 93%/94% thresholds, and dual-mode SYNC input supporting skip mode (ultra-low IQ), forced PWM, or external clock synchronization with ±20% frequency lock range.

Key Specifications

Pinout & Package

MAX25239AFFB/VY+T 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 MAX25240AFFB/VY+T and LM61480QRNXTQ1, the MAX25239AFFB/VY+T uniquely combines 2.1MHz operation, ±6% spread-spectrum, AEC-Q100 Grade 1 qualification, and 2V cold-crank capability in a single 22-pin FC2QFN package-enabling smaller, quieter, and more robust power designs for next-gen ADAS and infotainment systems.

Availability

MAX25239AFFB/VY+T is available at Aetrix Electronics and suitable for ADAS ECU, infotainment systems, and start-stop systems requiring stable component supply, long-term automotive lifecycle support, and traceable RoHS-compliant sourcing.

Supply support for MAX25239AFFB/VY+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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving automotive, industrial, communications, and consumer markets with precision power, sensing, and connectivity solutions.

The MAX25239/MAX25240 product line delivers highly integrated, AEC-Q100-qualified buck-boost converters optimized for demanding automotive power applications-including ADAS, infotainment, and body electronics-where wide input range, ultra-low IQ, and thermal resilience are mandatory.

FAQ

What is the minimum input voltage required for MAX25239AFFB/VY+T to start up and regulate?

The MAX25239AFFB/VY+T achieves initial startup at 4.5V (VSUP rising), but its operational input range extends down to 2V once running-enabling reliable regulation during cold-crank events where battery voltage drops below 6V. This 2V–36V range is sustained across the full –40°C to +125°C temperature range, and the IC tolerates 42V transients without damage or latch-up.

Does MAX25239AFFB/VY+T support both fixed and adjustable output voltages?

Yes, the MAX25239AFFB/VY+T supports two configuration modes: fixed output (5.0V or 11.5V, selected by internal trim) and externally adjustable output (3V–20V) via a resistor divider on the FB pin. The feedback reference voltage is tightly controlled at 0.800V ±1.75%, ensuring ±2% total output accuracy over line, load, and temperature conditions.

How does the SYNC pin function on MAX25239AFFB/VY+T?

The SYNC pin on MAX25239AFFB/VY+T serves three distinct roles: grounding it enables skip mode for ultra-low IQ operation; pulling it high to VCC forces fixed-frequency PWM; and applying an external clock (280kHz–2.7MHz) synchronizes the internal oscillator within ±20% frequency lock range. The device locks to the external clock in two cycles and reverts to internal timing if the external signal is absent for >2 cycles.

What thermal performance can be expected from MAX25239AFFB/VY+T in a standard 4-layer PCB?

In a JEDEC-standard 4-layer board, the MAX25239AFFB/VY+T exhibits a junction-to-ambient thermal resistance (θJA) of 33.3°C/W and junction-to-board (θJB) of 7.6°C/W. With its 22-pin FC2QFN package and exposed thermal pad, it sustains 6A continuous output at +70°C ambient without forced airflow-derating linearly above that point at 30mW/°C-making it suitable for compact, fanless automotive ECUs.

Is MAX25239AFFB/VY+T qualified for automotive applications?

Yes, the MAX25239AFFB/VY+T is fully AEC-Q100 Grade 1 qualified (–40°C to +125°C), with lifetime reliability validated for 95,000 hours at TJ = +125°C and 5,000 hours at +150°C. It meets stringent automotive requirements including ISO 7637-2 transient immunity (42V), ESD protection (±2kV HBM), and thermally enhanced packaging-making it suitable for safety-critical ADAS and powertrain-adjacent systems.