Infineon Technologies IR3842MTRPBF

Overview

IR3842MTRPBF from Infineon Technologies is a highly integrated 4A synchronous buck regulator with co-packaged high- and low-side MOSFETs, PWM controller, and bootstrap diode in a 5mm × 6mm Power QFN package. It delivers precise 0.7V to 0.9×Vin output voltage with ±1% reference accuracy, supports 250kHz–1.5MHz programmable switching frequency, and operates across 1.5V–16V input range for point-of-load power in server and telecom systems.

For engineers reviewing the IR3842MTRPBF datasheet, IR3842MTRPBF pinout, IR3842MTRPBF application, or IR3842MTRPBF equivalent, key selection criteria include its integrated current-limit programming (OCSet), pre-bias start-up capability, PGood open-drain status output, soft-start/shutdown control via SS/SD pin, and thermal shutdown at 140°C junction temperature.

Technical Context

The IR3842MTRPBF implements a voltage-mode synchronous buck architecture with an internal error amplifier (GBWP = 20–40 MHz, slew rate = 7–20 V/μs) and programmable oscillator using an external RT resistor. Its high-bandwidth compensation node (Comp) enables stable loop response under fast load transients, while the dedicated Seq pin supports tracking-based power sequencing with external resistors.

Protection logic includes hiccup-mode overcurrent response triggered by OCSet pin voltage, thermal shutdown with 20°C hysteresis, and UVLO on both VCC (4.06–4.46 V start threshold) and Enable (1.14–1.36 V start). The integrated bootstrap diode eliminates external component need, and PGnd/Gnd separation minimizes noise coupling between power and signal grounds.

Key Specifications

Pinout & Package

IR3842MTRPBF uses a 15-pin 5mm × 6mm Power QFN package with 0.9 mm height, exposed thermal pad (PGnd-connected), and RoHS-compliant lead-free finish.

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 TPS544B20RJER, the IR3842MTRPBF uniquely balances integration (co-packaged FETs + bootstrap diode), analog programmability (Rt, OCSet, SS), and sequencing capability (Seq) in a thermally optimized 5mm × 6mm package-making it optimal for analog-controlled, medium-power PoL where layout simplicity and reliability are critical.

Availability

IR3842MTRPBF is available at Aetrix Electronics and suitable for server VRMs, telecom line cards, enterprise SSD power rails, and 5G baseband unit PoL designs requiring stable component supply, long-lifecycle support, and production-ready qualification.

Supply support for IR3842MTRPBF 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 manufacturer specializing in power management, automotive, and industrial control ICs, with leadership in silicon and silicon carbide power devices.

The IR3842 belongs to Infineon's SupIRBuck™ family-designed specifically for space-constrained, high-efficiency point-of-load DC/DC conversion in datacenter, networking, and communications infrastructure.

FAQ

What is the minimum recommended output capacitance for stable operation at 4A load?

The IR3842MTRPBF datasheet specifies a minimum 22μF ceramic output capacitor with ≤5mΩ ESR for 4A operation at 600kHz. Using two 10μF X5R 0805 capacitors in parallel achieves optimal high-frequency decoupling and reduces ripple below 10mVpp. Lower capacitance may cause instability under fast load steps due to insufficient phase margin.

Can the IR3842MTRPBF safely start into a pre-biased output voltage?

Yes-the IR3842MTRPBF features enhanced pre-bias start-up logic that actively prevents reverse current flow and output voltage collapse during startup into a pre-charged rail. This is confirmed in the datasheet's "Enhanced Pre-Bias Start-up" section and validated across −40°C to +125°C ambient, making it suitable for hot-swap and multi-rail sequencing applications.

How is overcurrent protection configured and what happens during a fault?

Overcurrent protection is set by connecting a resistor from OCSet pin to SW pin; typical values yield 23.6μA (at 500kHz) to trigger hiccup mode. During fault, the device disables switching, waits ~4.1ms (4096 cycles), then attempts restart. This cycle repeats until fault clears-preventing thermal damage while maintaining system visibility via PGood deassertion.

Is the thermal pad (PGnd) electrically connected to internal MOSFET sources?

Yes-the exposed thermal pad is internally bonded to the PGnd terminal and serves as the primary current return path for both high- and low-side MOSFETs. It must be soldered to a dedicated copper pour connected to the system's power ground plane with ≥6 thermal vias (0.3mm diameter) to achieve θJA ≈ 35°C/W and sustain 4A continuous operation at +85°C ambient.