Analog Devices Inc./Maxim Integrated MAX25231ATCA/V+T

Overview

MAX25231ATCA/V+T from Analog Devices is a synchronous automotive buck converter with integrated high-side and low-side MOSFETs, delivering up to 1.2A at fixed 5V output with ±2% accuracy over 6V–18V input, 3.5µA quiescent current in standby, and 2.1MHz switching frequency. It operates across 3.5V–36V input, supports 99% duty cycle for dropout operation, and features PGOOD monitoring - ideal for always-on automotive power rails.

For engineers reviewing the MAX25231ATCA/V+T datasheet, MAX25231ATCA/V+T pinout, MAX25231ATCA/V+T application, or MAX25231ATCA/V+T equivalent, key selection criteria include AEC-Q100 qualification, 40V load-dump tolerance, spread-spectrum EMI reduction, fixed 5V output configuration, and TDFN-EP (3mm × 3mm, 12-pin) thermal performance with θ_JA = 41°C/W.

Technical Context

The MAX25231ATCA/V+T uses current-mode control with no external compensation required, enabling stable regulation across wide input ranges and fast transient response. Its 66ns minimum on-time supports high step-down ratios (e.g., 36V→5V), while internal soft-start (2.5ms typ) and thermal shutdown (175°C) ensure robust startup and fault handling.

It supports dual operating modes via SYNC pin: skip mode for ultra-low I_Q at light loads (<150mA), and forced-PWM (FPWM) for constant-frequency EMI control. Spread-spectrum modulation (±6% around 2.1MHz) is enabled independently via SPS pin, active only during internal oscillator operation.

Key Specifications

Pinout & Package

MAX25231ATCA/V+T is housed in a 3mm × 3mm, 12-pin TDFN-EP package with exposed pad (Package Code: TD1233+2C), optimized for thermal dissipation (θ_JA = 41°C/W on 4-layer board) and space-constrained automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480-Q1 and MPQ4420AGL-AEC1, the MAX25231ATCA/V+T offers superior quiescent current (3.5µA vs 4.5µA/12µA), integrated spread-spectrum EMI control, and tighter output accuracy (±2% vs ±3%), making it optimal for space-constrained, low-power automotive modules requiring certified reliability.

Availability

MAX25231ATCA/V+T is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, telematics control units, and gateway microcontroller power supplies requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.

Supply support for MAX25231ATCA/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 digital signal processing semiconductors, serving automotive, industrial, communications, and healthcare markets with precision power, sensing, and signal chain solutions.

The MAX25231 family is designed specifically for automotive power management - delivering ultra-low I_Q, high-voltage resilience, and AEC-Q100 reliability in compact packages for next-generation vehicle electronics.

FAQ

What is the maximum input voltage the MAX25231ATCA/V+T can withstand during load-dump events?

The MAX25231ATCA/V+T is rated for 40V absolute maximum input voltage on the SUP pin, enabling direct handling of ISO 7637-2 Pulse 5a load-dump transients without external protection components. This specification is validated across the full -40°C to +125°C temperature range and is integral to its AEC-Q100 Grade 1 qualification. The device remains functional and undamaged during these events, maintaining regulation if input stays within operational limits post-transient.

Does the MAX25231ATCA/V+T require external feedback resistors to set the 5V output?

No, the MAX25231ATCA/V+T does not require external feedback resistors. It is factory-trimmed for fixed 5V output with ±2% accuracy; the FB pin is internally connected to the 1V reference and must be left unconnected or tied to BIAS in this variant. External resistor dividers are only used with the adjustable-output MAX25231ATCD/V+T variant - using them with MAX25231ATCA/V+T would disrupt regulation and is not supported.

How does the MAX25231ATCA/V+T achieve 3.5µA quiescent current, and under what conditions is it guaranteed?

The MAX25231ATCA/V+T achieves 3.5µA typical quiescent current in standby mode - activated automatically when output load drops below ~5mA and skip mode is enabled (SYNC grounded or floating). In this state, the internal high-voltage LDO is disabled and non-essential circuitry is powered down. The 3.5µA value is specified for the 5V variant at T_A = +25°C, no load, and skip mode enabled; actual production units are tested to 5.6–10µA (max) per Electrical Characteristics table.

Can the MAX25231ATCA/V+T operate in dropout, and what is the minimum input voltage to maintain 5V output?

Yes, the MAX25231ATCA/V+T supports dropout operation with up to 99% duty cycle, allowing it to sustain 5V output down to an input voltage of approximately 5.05V (5V ÷ 0.99). This capability is critical for automotive cold-crank scenarios where battery voltage may dip to 3.5V - the device remains functional but enters dropout only when VIN approaches V_OUT; regulation resumes immediately once VIN rises above dropout threshold.

What thermal management practices are recommended for the MAX25231ATCA/V+T in high-ambient environments?

For reliable operation above +85°C ambient, solder the exposed pad of the MAX25231ATCA/V+T directly to a large internal PGND copper plane with ≥4 thermal vias (0.3mm diameter) connecting to inner and bottom layers. Route PGND and AGND together only at the output capacitor's ground terminal. Maintain ≥200mm² of 2oz copper under the device, and avoid placing heat-generating components nearby. These practices ensure junction temperature stays below +150°C - the absolute maximum rating - even at full 1.2A load in +105°C under-hood environments.