Infineon Technologies IR3840WMTR1PBF

Overview

IR3840WMTR1PBF from Infineon Technologies is a highly integrated 12A synchronous buck regulator with on-die high- and low-side MOSFETs, programmable switching frequency up to 1.5 MHz, precision 0.7 V ±1% reference voltage, and integrated bootstrap diode. It delivers >96% peak efficiency at 12 V_IN/1.8 V_OUT/12 A in server point-of-load applications.

For engineers reviewing the IR3840WMTR1PBF datasheet, IR3840WMTR1PBF pinout, IR3840WMTR1PBF application, or IR3840WMTR1PBF equivalent, key selection criteria include its wide 1.5–16 V input range, 0.7–0.9×V_IN output adjustability, hiccup-mode overcurrent protection, thermal shutdown, and support for pre-bias start-up in distributed power architectures.

Technical Context

The IR3840WMTR1PBF implements a current-mode PWM control architecture with a high-bandwidth error amplifier (GBWP: 20–40 MHz, slew rate: 7–20 V/μs) and programmable fixed-off-time ramp generator (1.8 V_p-p, 0.6 V offset). Its dual-ground architecture separates signal ground (GND pins 4 & 15) from power ground (PGND pin 10) to minimize noise coupling in high-di/dt switching paths.

It supports multi-rail sequencing via the SEQ pin, soft-start timing via external capacitor on SS/SD (pin 6), and precise current limiting via resistor-connected OCSet (pin 7) referenced to SW. The PGood open-drain output (pin 8) provides regulated output validation with 256-cycle delay and hysteresis of ±35 mV around 0.7 V feedback threshold.

Key Specifications

Pinout & Package

IR3840WMTR1PBF uses a thermally enhanced 5 mm × 6 mm Power QFN package with 0.9 mm height and exposed thermal pad (pin 10 = PGND). Pin count: 15. RoHS-compliant, lead-free, halogen-free construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP8765GQ-Z and TPS544B20, the IR3840WMTR1PBF offers optimal balance of analog programmability (frequency, soft-start, OC limit), thermal robustness (−40°C to +125°C), and compact 5 × 6 mm footprint-making it ideal for cost-sensitive, high-reliability analog POL designs without digital overhead.

Availability

IR3840WMTR1PBF is available at Aetrix Electronics and suitable for server power delivery, storage controller regulation, and embedded telecom baseband cards requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for IR3840WMTR1PBF 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 control ICs, with global manufacturing and quality certification to ISO/TS 16949 and IECQ QC 080000.

The IR3840W SupIRBuck™ product line targets high-density, high-efficiency point-of-load conversion in datacenter and communications infrastructure, integrating power stages and control logic to reduce design cycle time and improve thermal performance.

FAQ

What is the minimum recommended output capacitance for stable operation at 12 A load?

The IR3840WMTR1PBF datasheet specifies stability with ≥220 μF total ceramic output capacitance (e.g., ten 22 μF/6.3 V X5R 0805 devices) and ESR ≤0.5 mΩ. Lower ESR improves transient response but requires careful attention to control loop compensation via the COMP pin network to avoid ringing or oscillation.

Can the IR3840WMTR1PBF operate with an input voltage below 1.5 V?

No. The absolute minimum input voltage is 1.5 V per the Recommended Operating Conditions table. Operation below this level risks failure to initiate switching, inaccurate regulation, or violation of internal bias requirements. The device will not function reliably at 1.2 V or lower, even if VCC is externally supplied.

How does the OCSet pin determine overcurrent threshold?

The OCSet pin senses voltage drop across a sense resistor connected between OCSet and SW. Threshold current I_OC = V_{REF_OC} / R_SENSE, where V_{REF_OC} is internally trimmed to 136–172 μA at 1.5 MHz (scaling inversely with f_SW). For example, a 10 mΩ resistor yields ~15 A trip at 500 kHz.

Is the thermal pad (pin 10, PGND) electrically connected to internal MOSFET sources?

Yes. The exposed thermal pad is internally bonded to the power ground (PGND) node and serves as the common source connection for both high-side and low-side MOSFETs. It must be soldered to a dedicated copper pour tied to the system's main power ground plane to ensure low-impedance thermal and electrical return.