Analog Devices Inc./Maxim Integrated MAX25232ATCF/V+

Overview

The MAX25232ATCF/V+ from Maxim Integrated is a 36V, 3A synchronous buck converter with integrated high-side and low-side MOSFETs, designed for automotive and industrial DC-DC conversion. It delivers ±2% output voltage accuracy in FPWM mode (6–18V input), features 65ns minimum on-time, 3.5µA quiescent current at no load, and operates at fixed 400kHz switching frequency-enabling compact designs in harsh environments such as engine control units.

For engineers reviewing the MAX25232ATCF/V+ datasheet, MAX25232ATCF/V+ pinout, MAX25232ATCF/V+ application, or MAX25232ATCF/V+ equivalent, key selection considerations include its AEC-Q100 qualification, 3.5V–36V input range, adjustable 3V–10V output via external resistor divider, 40V load-dump protection, and 99% dropout duty cycle capability.

Technical Context

The MAX25232ATCF/V+ implements current-mode control with internal compensation, eliminating external loop components. Its 400kHz fixed-frequency operation minimizes switching losses and maximizes efficiency across wide load ranges, while the 65ns minimum on-time supports high input-to-output voltage ratios (e.g., 24V→3.3V).

It integrates a 5V bias LDO, PGOOD monitoring, spread-spectrum modulation (enabled via SPS pin), and thermal shutdown at 175°C. The device enters skip mode automatically under light loads and transitions to forced-PWM when SYNC is tied to BIAS-providing deterministic EMI behavior during critical timing phases.

Key Specifications

Pinout & Package

The MAX25232ATCF/V+ is housed in a thermally enhanced 12-pin TDFN package (3mm × 3mm, exposed pad), optimized for high-power density and automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480QRTWRQ1 and TPS543B20RJNR, the MAX25232ATCF/V+ uniquely combines AEC-Q100 qualification, 36V input support, 3.5µA IQ, and 3V–10V adjustability in a 3mm×3mm TDFN-making it optimal for space-constrained, battery-sensitive automotive subsystems where analog flexibility outweighs digital control.

Availability

The MAX25232ATCF/V+ is available at Aetrix Electronics and suitable for automotive ECU, ADAS camera modules, industrial PLC I/O, and infotainment head units requiring stable component supply across extended temperature and voltage ranges.

Supply support for MAX25232ATCF/V+ 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

Maxim Integrated, now part of Analog Devices, designs precision analog, mixed-signal, and power management ICs for automotive, industrial, and communications markets.

The MAX25232 product line targets high-reliability automotive DC-DC conversion, emphasizing ultra-low IQ, wide input range, AEC-Q100 compliance, and minimal external component count for ECU and ADAS subsystems.

FAQ

What is the maximum input voltage the MAX25232ATCF/V+ can withstand during load-dump events?

The MAX25232ATCF/V+ is rated for 40V transient input during load-dump events per ISO 7637-2 Pulse 5a, enabling direct connection to automotive battery rails without external TVS diodes. This rating applies to the SUP pin, and the device remains functional after the transient if junction temperature stays within limits. The absolute maximum rating for SUP is +40V, and operation above 36V is limited to short-duration transients only. Designers should verify board-level clamping and thermal dissipation for repeated 40V exposure.

Can the MAX25232ATCF/V+ be configured for a 3.3V output, and how does its accuracy compare to fixed-output variants?

Yes, the MAX25232ATCF/V+ can be configured for 3.3V output using an external resistor divider on the FB pin, with typical accuracy of ±1.5% (based on FB reference tolerance of ±1.5% and resistor ratio error). Fixed-output variants like MAX25232ATCB offer ±2% total output accuracy in FPWM mode but lack adjustability. For 3.3V applications requiring highest precision, the fixed variant is preferred; for multi-voltage designs needing flexibility, MAX25232ATCF/V+ provides validated 3.3V capability with identical thermal and EMI performance.

Does the MAX25232ATCF/V+ support forced PWM (FPWM) mode, and how is it enabled?

Yes, the MAX25232ATCF/V+ supports forced PWM mode, which is enabled by connecting the SYNC pin to the internal BIAS supply (5V). In FPWM mode, the device operates continuously at its fixed 400kHz switching frequency regardless of load, eliminating low-frequency beat notes and improving EMI predictability. This mode is essential for noise-sensitive applications like radar or audio subsystems. When SYNC is left floating or grounded, the device defaults to skip mode for highest light-load efficiency.

What is the purpose of the SPS pin on the MAX25232ATCF/V+, and does it affect SYNC functionality?

The SPS (Spread-Spectrum) pin on the MAX25232ATCF/V+ enables ±3% frequency dithering of the internal oscillator to reduce radiated EMI peaks. It operates independently of the SYNC pin: spread spectrum is active only when the device uses its internal clock (i.e., SYNC is unconnected or grounded), and is disabled when an external clock is applied to SYNC. Pulling SPS high activates dithering; leaving it unconnected or low disables it. This allows simultaneous optimization of both EMI and timing determinism.

How does the MAX25232ATCF/V+ handle thermal overload, and what happens after shutdown?

The MAX25232ATCF/V+ features thermal shutdown at +175°C (typical junction temperature), with 15°C hysteresis. Upon reaching this threshold, the device disables switching, turns off both FETs, and holds PGOOD low. Once the die cools to +160°C (175°C − 15°C), it automatically initiates a full soft-start sequence (5.5ms ramp) before resuming regulation. This behavior prevents thermal cycling damage and ensures safe restart only after adequate cooling-critical for enclosed automotive enclosures where airflow is limited.