Analog Devices Inc./Maxim Integrated MAX17233ETIR+T

Overview

MAX17233ETIR+T from Maxim Integrated is a dual synchronous step-down DC-DC controller with integrated gate drivers, designed for independent 5V/3.3V or adjustable 1V–10V power rails in industrial and embedded systems. It operates from 3.5V to 36V input (42V transient tolerant), delivers up to 10A per channel, and supports 1MHz–2.2MHz PWM or PFM operation with 180° interleaving.

For engineers reviewing the MAX17233ETIR+T datasheet, MAX17233ETIR+T pinout, MAX17233ETIR+T application, or MAX17233ETIR+T equivalent, key selection considerations include its dual-buck architecture with independent enable (EN1/EN2), 20µA quiescent current in PFM mode, ±1% fixed-output accuracy, spread-spectrum EMI reduction, and TQFN-EP 28-pin package with exposed thermal pad.

Technical Context

The MAX17233ETIR+T implements current-mode control with dual PWM/PFM selectable operation: PWM maintains constant 1–2.2MHz switching frequency across load, while PFM disables negative inductor current and skips pulses at light loads to achieve 20µA quiescent current. Its 180° phase shift between buck stages reduces input ripple and enables cascaded supply designs.

It integrates high-side (DH1/DH2) and low-side (DL1/DL2) gate drivers with shoot-through protection, supports external MOSFETs via LX1/LX2, and features dual error amplifiers (COMP1/COMP2) with RC compensation for stable regulation across 1V–10V output range. The BIAS LDO (5V ±5%) powers internal circuitry and can be bypassed via EXTVCC for improved efficiency.

Key Specifications

Pinout & Package

MAX17233ETIR+T is housed in a 28-pin TQFN-EP (5mm × 5mm) package with exposed thermal pad, rated for -40°C to +85°C ambient operation. The exposed pad must be soldered to a PCB thermal plane for effective heat dissipation (θJC = 3°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX17232ETIS+ and TPS544B20RTWR, the MAX17233ETIR+T uniquely combines 2.2MHz operation, spread-spectrum EMI reduction, and true dual-rail independence in a single 28-pin package - eliminating inter-rail timing skew and simplifying layout for cost-sensitive industrial and medical designs.

Availability

MAX17233ETIR+T is available at Aetrix Electronics and suitable for industrial PLCs, automotive body controllers, medical diagnostics, networking edge devices, and portable instrumentation requiring stable component supply and long lifecycle support.

Supply support for MAX17233ETIR+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

Maxim Integrated, now part of Analog Devices, designs high-performance analog and mixed-signal ICs for power management, sensing, and communications in demanding industrial, automotive, and medical applications.

The MAX17232/MAX17233 product line delivers dual synchronous buck controllers optimized for compact, efficient, and EMI-robust point-of-load regulation - addressing the need for reliable multi-rail power in space- and thermal-constrained embedded systems.

FAQ

What is the maximum input voltage rating for MAX17233ETIR+T, and how does it handle transients?

The MAX17233ETIR+T has an absolute maximum input voltage rating of +42V for up to 1 second, with normal operation specified from 3.5V to 36V. Its internal protection circuitry clamps input transients above 42V to prevent damage, enabling reliable use in 24V industrial buses and automotive systems subject to load-dump events. This transient tolerance is built into the IN pin structure and does not require external TVS diodes for standard ISO 16750-2 compliance.

Can MAX17233ETIR+T generate non-standard output voltages like 1.2V or 2.5V?

Yes, the MAX17233ETIR+T supports adjustable output voltages from 1V to 10V using external resistive dividers on FB1 and FB2 pins. In adjustable mode, the internal reference is 1.0V (±1%), so a 1.2V output requires a 1:0.2 divider (e.g., 100kΩ top, 20kΩ bottom), and a 2.5V output uses a 1:1.5 divider (e.g., 100kΩ top, 150kΩ bottom). The device maintains ±1% regulation accuracy across temperature and load for all values in this range.

How does the 180° phase shift between Buck 1 and Buck 2 improve system performance?

The 180° phase shift in MAX17233ETIR+T reduces input capacitor RMS current by approximately 30% compared to in-phase operation, allowing smaller, lower-ESR ceramic input capacitors. It also lowers peak-to-peak input ripple voltage and spreads EMI energy across a wider frequency band - easing compliance with conducted emission limits and reducing filter component count in compact power modules.

What is the role of the EXTVCC pin, and when should it be used?

The EXTVCC pin on MAX17233ETIR+T allows bypassing the internal 5V BIAS LDO by connecting an external 3.1V–5.2V supply (e.g., one of the buck outputs). When active, EXTVCC reduces internal power dissipation and improves light-load efficiency. It is recommended when a stable 3.3V or 5V rail is already available - such as using Buck 2's 3.3V output to power EXTVCC while Buck 1 generates 5V for the system.

Does MAX17233ETIR+T support forced PWM mode, and how is it enabled?

Yes, MAX17233ETIR+T supports forced PWM mode to maintain constant switching frequency under all load conditions. It is enabled by driving the FSYNC pin high (≥1.5V), which disables skip-mode zero-crossing detection. In this mode, the inductor current reverses at light loads, improving transient response and eliminating variable-frequency harmonics - ideal for noise-sensitive applications like audio or RF subsystems.