Analog Devices Inc./Maxim Integrated MAX25231ATCB/V+T

Overview

MAX25231ATCB/V+T from Analog Devices is a synchronous automotive buck converter with integrated high-side and low-side MOSFETs, delivering 1.2A at fixed 3.3V output with ±2% accuracy over 6V–18V input, 3.5µA quiescent current in standby, and 2.1MHz switching frequency - deployed in always-on vehicle infotainment power rails.

For engineers reviewing the MAX25231ATCB/V+T datasheet, MAX25231ATCB/V+T pinout, MAX25231ATCB/V+T application, or MAX25231ATCB/V+T equivalent, key selection criteria include AEC-Q100 qualification, 3.5V–36V input range with 40V load-dump tolerance, 99% dropout duty cycle, spread-spectrum EMI reduction, and TDFN-EP thermal performance.

Technical Context

The MAX25231ATCB/V+T implements current-mode control with internal compensation, enabling stable regulation without external loop components. Its 66ns minimum on-time supports high step-down ratios (e.g., 24V→3.3V), while the 2.1MHz fixed-frequency operation ensures minimal AM-band interference and compact passive sizing.

It features dual operating modes: skip mode for ultra-low IQ (<3.5µA no-load) and forced-PWM (via SYNC pin) for deterministic EMI. The PGOOD open-drain output provides accurate voltage monitoring with 93.5% rising threshold and 65µs debounce, and thermal shutdown activates at 175°C with 15°C hysteresis.

Key Specifications

Pinout & Package

MAX25231ATCB/V+T is housed in a 3mm × 3mm, 12-pin TDFN package with exposed pad (TD1233+2C), optimized for automotive thermal dissipation (θ_JA = 41°C/W on 4-layer board). The exposed pad must be soldered to PGND for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480QRTWRQ1 and TPS62933QPWRRQ1, the MAX25231ATCB/V+T uniquely balances AEC-Q100 Grade 1 compliance, 3.5µA IQ, 2.1MHz EMI control, and production-proven 3.3V fixed-output stability - making it optimal for space-constrained, battery-sensitive automotive modules where qualification and low-noise operation are non-negotiable.

Availability

MAX25231ATCB/V+T is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and industrial CAN node power supplies requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant sourcing.

Supply support for MAX25231ATCB/V+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 power management semiconductors, serving automotive, industrial, and communications markets with precision, reliability, and longevity.

The MAX25231 family targets automotive power conversion needs - specifically compact, low-IQ, AEC-Q100-compliant buck regulators for always-on subsystems where thermal density, EMI, and battery preservation are critical design constraints.

FAQ

What is the maximum input voltage the MAX25231ATCB/V+T can withstand during load-dump events?

The MAX25231ATCB/V+T is rated for 40V absolute maximum input voltage per its Absolute Maximum Ratings table. This allows it to survive ISO 7637-2 Load Dump Pulse 5a (35V peak, 400ms) without external protection, making it suitable for direct connection to automotive battery rails without additional TVS diodes in most implementations.

Does the MAX25231ATCB/V+T require external feedback resistors to set the 3.3V output?

No, the MAX25231ATCB/V+T is factory-trimmed for fixed 3.3V output. The FB pin is internally connected to the BIAS rail, eliminating the need for external resistor dividers. External feedback is only required for the adjustable variant MAX25231ATCD/V+, not for MAX25231ATCB/V+T.

How does the MAX25231ATCB/V+T achieve 3.5µA quiescent current?

The MAX25231ATCB/V+T achieves 3.5µA IQ by entering standby mode at ultra-light loads: the internal BIAS LDO is disabled, analog blocks are powered down, and only essential regulation circuitry remains active. This state is automatically entered when output current falls below ~5mA, and is confirmed in Electrical Characteristics for MAX25231ATCB/V+ with no load and no switching.

Can the MAX25231ATCB/V+T operate in dropout, and what is its minimum input voltage for 3.3V output?

Yes, the MAX25231ATCB/V+T supports dropout operation with up to 99% duty cycle. For 3.3V output, it maintains regulation down to approximately 3.5V input (per VSUP min spec), and can sustain output during cranking events as low as 5.5V input due to its extended dropout capability and internal timing adjustments.

Is the MAX25231ATCB/V+T pin-compatible with other variants in the MAX25231 family?

Yes, all MAX25231 variants - including MAX25231ATCA/V+, MAX25231ATCB/V+, and MAX25231ATCD/V+ - share identical 12-pin TDFN package (TD1233+2C), pinout, and footprint. This allows drop-in replacement between 3.3V, 5V, and adjustable versions without PCB redesign, provided external components match the selected output configuration.