Infineon Technologies IR3475MTRPBF

Overview

IR3475MTRPBF from Infineon Technologies is a fully integrated 10A synchronous buck regulator with on-die high- and low-side MOSFETs, constant-on-time (COT) control, 0.5V ±1% reference, and programmable switching frequency up to 750 kHz. It operates from 3V–27V input and delivers 0.5V–12V output, supporting pre-bias startup and forced CCM mode in notebook, graphics card, and 12V/24V POL applications.

For engineers reviewing the IR3475MTRPBF datasheet, IR3475MTRPBF pinout, IR3475MTRPBF application, or IR3475MTRPBF equivalent, key selection criteria include thermally compensated overcurrent protection, power-good open-drain output, enable input with voltage monitoring, and 4mm × 5mm QFN thermal performance under 10A continuous load.

Technical Context

The IR3475 implements a hysteretic constant-on-time control architecture that eliminates external loop compensation while maintaining stable regulation across wide load and input ranges. Its internal 25 mΩ high-side and 13 mΩ low-side MOSFETs enable high-efficiency operation even at light loads, with soft-start timing set via an external capacitor on the SS pin.

Protection features are tightly integrated: under/over-voltage fault detection on FB (±7.5 mV hysteresis), thermal shutdown at 125°C (20°C hysteresis), and ISET-based current limiting with 4400 ppm/°C temperature coefficient. The FCCM pin allows deterministic transition between DCM and forced CCM modes using simple 0V/3.3V logic levels.

Key Specifications

Pinout & Package

IR3475MTRPBF uses a thermally enhanced 20-pin 4mm × 5mm QFN package with exposed thermal pad (PGND-connected). Pin 1 is marked by a dot; pins are arranged in two rows (10 per side), with GND and PGND pins distributed for optimal thermal and noise separation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2315DJ-LF-Z and TPS546B24RVFT, IR3475MTRPBF uniquely combines 10A integration, analog COT control without compensation, and dual-mode FCCM in a compact QFN - making it optimal for analog-centric, space-constrained, and thermally demanding POL designs.

Availability

IR3475MTRPBF is available at Aetrix Electronics and suitable for notebook CPU core power, graphics card memory rails, and 12V distributed power systems requiring stable component supply and long-term industrial availability.

Supply support for IR3475MTRPBF 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

Infineon Technologies is a German semiconductor leader specializing in power management, automotive MCUs, and industrial sensors, with global manufacturing and quality certification to ISO/TS 16949 and IEC 61508.

The SupIRBuck™ product line delivers highly integrated DC/DC regulators targeting space-constrained, high-efficiency point-of-load applications in computing, consumer, and industrial equipment - emphasizing ease-of-use, thermal robustness, and analog control simplicity.

FAQ

What is the recommended layout practice for the thermal pad of IR3475MTRPBF?

The exposed thermal pad (pins 4, 11, 17) must be soldered to a solid PGND copper pour with ≥4 thermal vias (0.3mm diameter, spaced ≤1.5mm apart) connecting to inner-layer ground planes. Avoid splitting the pad or routing signals underneath it to maintain low-impedance heat transfer and minimize switching noise coupling.

Can IR3475MTRPBF operate with a 5V-only input supply?

Yes - the 3V–27V input range includes 5V operation. At VIN = 5V, the device delivers up to 10A output with VOUT ≥ 0.5V. Ensure VCC is properly decoupled (≥1 µF ceramic) and BOOT capacitor is sized for 5V–0.5V = 4.5V swing; typical 0.22 µF X5R is sufficient per datasheet Figure 4.

How is the overcurrent threshold set using the ISET pin?

Connect a resistor from ISET (pin 2) to PHASE (pin 12). The current sourced by ISET (19 µA typ.) flows through this resistor, developing a voltage sensed by the current-limit comparator. For example, a 10 kΩ resistor sets ~190 mV threshold, corresponding to ~10A with typical RDS(on) values and sensing gain.

Does IR3475MTRPBF support output voltages below 0.5V?

No - the internal reference is fixed at 0.5V ±1%, and the FB pin is designed for resistive divider networks that scale VOUT down to this reference. Output voltages below 0.5V cannot be regulated; the minimum valid VOUT is 0.5V, as confirmed in Recommended Operating Conditions (page 7) and Electrical Specifications (page 7).