Infineon Technologies IR3557MTRPBF

Overview

IR3557MTRPBF from Infineon Technologies (formerly International Rectifier) is a 40A integrated PowIRstage® power stage combining synchronous buck gate driver, control MOSFET, synchronous MOSFET, and Schottky diode in a single 6 mm × 6 mm PQFN package. It supports 4.5–15 V input, 0.25–5.5 V output, 1 MHz switching, and delivers precise on-chip current sensing (5 mV/A with temperature compensation) for CPU/GPU core VR applications.

For engineers reviewing the IR3557MTRPBF datasheet, IR3557MTRPBF pinout, IR3557MTRPBF application, or IR3557MTRPBF equivalent, key selection criteria include its integrated current-sense accuracy, Body-Braking™ transient support, diode emulation mode for light-load efficiency, thermal flag reporting (8 mV/°C), and compatibility with 3.3 V tri-state PWM controllers in high-density server VRMs.

Technical Context

The IR3557 implements a co-packaged synchronous buck power stage where the driver IC precisely times gate drive signals to minimize shoot-through and switch-node ringing. Its internal current-sense algorithm uses MOSFET R_DS(on) tracking with analog temperature compensation, delivering better DC accuracy than external DCR-based sensing.

It integrates cycle-by-cycle overcurrent protection with self-preservation, phase fault detection, preliminary overvoltage flag, and overtemperature protection with analog die temperature output (8 mV/°C) and digital thermal flag pulled up to 3.3 V - all operating within 4.5–7 V V_CC/V_DRV supply range.

Key Specifications

Pinout & Package

IR3557MTRPBF is housed in a thermally enhanced 32-pin PQFN (6 mm × 6 mm, 0.9 mm height) with exposed thermal pad. Pin functions are validated per Infineon's IR3557 datasheet (V3.0, May 2014).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated power stage applications.

Compared with IR3557MTRPBF, IR35203MTRPBF trades current capacity and thermal telemetry for lower cost and smaller size, while MP86957GQZ-P adds digital configurability at the expense of analog simplicity and board area - making IR3557 optimal for analog-controlled, space-constrained server CPU VRMs demanding precision thermal and current feedback.

Availability

IR3557MTRPBF is available at Aetrix Electronics and suitable for CPU core VRMs, GPU power stages, ASIC point-of-load converters, and DDR memory VDDQ supplies requiring stable component supply, high thermal reliability, and precise analog telemetry.

Supply support for IR3557MTRPBF 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 acquired International Rectifier in 2015 and continues development of its PowIRstage® family for high-efficiency power conversion.

The PowIRstage® product line targets high-frequency, high-current DC-DC conversion in server, AI accelerator, and telecom infrastructure, emphasizing integration, thermal performance, and analog sensing fidelity.

FAQ

What is the recommended PCB layout for optimal thermal performance?

Use a minimum 2 oz copper thermal pad connected to ≥4 internal ground planes via ≥12 thermal vias (0.3 mm diameter, 0.6 mm pitch). Keep AGND and PGND traces separate until star-point connection at the thermal pad. Route PWM and TEMP traces away from high-dI/dt paths to avoid noise coupling into analog sensing.

Does IR3557MTRPBF require an external bootstrap capacitor?

No. The IR3557MTRPBF integrates a charge pump for high-side gate drive, eliminating the need for an external bootstrap capacitor. This simplifies layout, reduces component count, and avoids bootstrap-related startup issues or voltage droop during sustained 100% duty cycle operation.

How does the on-chip current sensing compare to external DCR sensing?

IR3557MTRPBF achieves ±3% full-scale current measurement accuracy from –40°C to +125°C using MOSFET R_DS(on) tracking with on-die temperature compensation. This outperforms typical DCR-based methods (±5–8% error) that suffer from inductor tolerance, temperature drift, and PCB trace resistance errors.

Can IR3557MTRPBF operate with a 3.3 V-only supply?

Yes - the PWM input is compatible with 3.3 V tri-state logic, and the V_CC/V_DRV supply accepts 4.5–7 V. However, a separate 5 V or 6 V bias supply is required for V_CC/V_DRV; the device does not generate its own gate-drive bias from the 3.3 V PWM rail.