Analog Devices Inc./Maxim Integrated MAX25232ATCB/V+

Overview

The MAX25232ATCB/V+ from Maxim Integrated is a 3.3V fixed-output, 3A synchronous buck converter with integrated high-side and low-side MOSFETs, operating from 3.5V to 36V input and delivering ±2% output accuracy in FPWM mode. It features 3.5µA quiescent current at no load, 65ns minimum on-time, and AEC-Q100 qualification for automotive power rails.

For engineers reviewing the MAX25232ATCB/V+ datasheet, MAX25232ATCB/V+ pinout, MAX25232ATCB/V+ application, or MAX25232ATCB/V+ equivalent, key selection criteria include its 3.3V fixed output, 2.1MHz switching frequency, 99% dropout capability, PGOOD monitoring, and spread-spectrum EMI reduction - all in a 3mm × 3mm TDFN-EP package.

Technical Context

This device implements current-mode control with internal compensation, enabling stable regulation without external loop components. Its 65ns minimum on-time supports high step-down ratios (e.g., 24V-to-3.3V), while the 2.1MHz fixed-frequency operation minimizes external inductor and capacitor size.

Operation includes dual modes: forced-PWM (FPWM) when SYNC is tied to BIAS, ensuring constant frequency and predictable EMI; and skip mode under light loads, where the IC enters ultra-low-power standby (3.5µA IQ) by disabling nonessential circuitry and turning off the internal LDO.

Key Specifications

Pinout & Package

Package: 12-pin TDFN-EP (3mm × 3mm), exposed pad soldered to PCB ground plane for thermal dissipation (θ_JA = 41°C/W, θ_JC = 9°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480QRTWRQ1 and TPS543320RPYR, the MAX25232ATCB/V+ delivers superior ultra-low-quiescent performance (3.5µA), integrated spread spectrum, and AEC-Q100 qualification in a smaller 3mm × 3mm package - making it optimal for space-constrained, battery-sensitive automotive modules where EMI and qualification are critical.

Availability

MAX25232ATCB/V+ is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, ADAS camera ECUs, and high-voltage DC-DC auxiliary rails requiring stable component supply across extended temperature and lifecycle demands.

Supply support for MAX25232ATCB/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 automotive power conversion with AEC-Q100 qualification, ultra-low IQ, and robust transient handling - specifically engineered for body electronics, ADAS, and infotainment systems demanding high reliability in harsh environments.

FAQ

What is the output voltage of the MAX25232ATCB/V+ and how is it set?

The MAX25232ATCB/V+ delivers a factory-trimmed fixed 3.3V output with ±2% accuracy in forced-PWM mode. Unlike adjustable variants (e.g., MAX25232ATCF), it does not require external resistors - FB is internally shorted to BIAS. This eliminates feedback divider errors and simplifies layout for automotive applications where long-term stability and reduced BOM count are critical. The MAX25232ATCB/V+ achieves this via laser-trimmed internal reference and error amplifier.

Does the MAX25232ATCB/V+ support spread-spectrum frequency modulation, and how is it enabled?

Yes, the MAX25232ATCB/V+ supports spread-spectrum modulation to reduce EMI peaks. It is enabled by driving the SPS pin high (≥1.4V); the internal oscillator then dithers ±3% around its nominal 2.1MHz frequency. When SPS is low or floating (default via 1MΩ pulldown), spread spectrum is disabled. This feature operates only when the internal oscillator is active - it does not affect externally synchronized operation via the SYNC pin.

What is the maximum duty cycle and dropout behavior of the MAX25232ATCB/V+?

The MAX25232ATCB/V+ supports up to 99% duty cycle, enabling operation in dropout - for example, regulating 3.3V output from a 5.5V input. In dropout, the high-side FET remains on continuously except for brief (~200ns) low-side pulses every 20µs to recharge the BST capacitor. This maintains gate drive while sustaining regulation, making the MAX25232ATCB/V+ ideal for automotive start-stop systems where input voltage dips below nominal.

How does the PGOOD signal function on the MAX25232ATCB/V+?

The PGOOD pin on the MAX25232ATCB/V+ is an open-drain output that goes high-impedance when V_OUT ≥ 93% of nominal (3.07V) and pulls low when V_OUT ≤ 92% (3.04V), with 60µs debounce in PWM mode. It requires an external 20kΩ pullup to BIAS or another supply. This precise threshold and fast response allow reliable power sequencing for downstream FPGAs or microcontrollers, and fault detection during load transients or overtemperature shutdown.

Is the MAX25232ATCB/V+ qualified for automotive applications, and what standards does it meet?

Yes, the MAX25232ATCB/V+ is AEC-Q100 qualified (Grade 1: –40°C to +125°C ambient), with tested performance across temperature, voltage, and lifetime. It withstands 40V load-dump transients per ISO 7637-2 and operates over 3.5V–36V input - covering cold-crank, normal, and surge conditions in 12V automotive systems. Its thermal shutdown (175°C) and hysteresis (15°C) ensure robustness in under-hood environments without derating.