Infineon Technologies IR3623MPBF

Overview

IR3623MPBF from Infineon Technologies is a high-frequency, 2-phase synchronous buck PWM controller configurable for dual independent outputs or current-sharing single output. It supports ratiometric/simultaneous voltage tracking and sequencing, operates with 180° phase shift to reduce input/output capacitance, features ±1% reference accuracy, and enables MOSFET R_DS(on)-based hiccup current limiting. It targets multi-rail point-of-load systems in graphics cards and telecom infrastructure.

For engineers reviewing the IR3623MPBF datasheet, IR3623MPBF pinout, IR3623MPBF application, or IR3623MPBF equivalent, key selection criteria include programmable 200–1200 kHz switching frequency per phase, dual independent soft-start and power-good outputs, precision enable/UVLO thresholds, VSEN-based overvoltage protection with 5 µs fault propagation delay, and thermal shutdown at 135°C with 20°C hysteresis.

Technical Context

The IR3623MPBF implements a two-phase oscillator with 180° phase separation to minimize input ripple and capacitor stress. Its error amplifiers (gm = 2.8–4.4 mS) drive PWM comparators referenced to a 0.8 V internal bandgap, with dedicated VP/FB pins per channel enabling flexible feedback configurations including remote sensing and DCR current sensing.

Sequencing is controlled via Track1/Track2 and Seq pins, supporting both simultaneous and ratiometric ramp-up/down modes. Overcurrent protection uses external OCSet resistors to set trip thresholds (17–27 µA), triggering hiccup mode with 15% duty cycle and 3 µA restart current-enabling robust, self-recovering fault handling without external circuitry.

Key Specifications

Pinout & Package

The IR3623MPBF is housed in a thermally enhanced 32-lead MLPQ package with exposed thermal pad connected to PCB ground plane via vias for Θ_JA = 36°C/W (4-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL6322IRZ and TPS51220ARGER, the IR3623MPBF uniquely supports dual independent outputs with full tracking/sequencing, external frequency programming, and MOSFET R_DS(on) current sensing-making it optimal for complex, multi-rail, high-performance power systems where flexibility and fault resilience are critical.

Availability

IR3623MPBF is available at Aetrix Electronics and suitable for embedded telecom systems, graphics card VRMs, and distributed point-of-load power architectures requiring stable component supply and long-term design-in support.

Supply support for IR3623MPBF 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 global semiconductor leader specializing in power management, automotive, and industrial control solutions, with deep expertise in high-efficiency power conversion ICs.

The IR3623MPBF belongs to Infineon's high-frequency synchronous buck controller product line, designed specifically for multi-phase, multi-rail point-of-load applications demanding precise sequencing, robust fault protection, and thermal resilience in space-constrained environments.

FAQ

What is the purpose of the OCGnd pin?

The OCGnd pin (Pin 20) serves as the dedicated ground reference for the overcurrent protection circuitry. It must be connected to the low-side MOSFET source node or a clean local ground to ensure accurate R_DS(on) current sensing. Separating this ground from the main signal ground minimizes noise coupling into the OCSet comparator, improving current limit accuracy and stability under high dv/dt conditions.

Can IR3623MPBF operate without an external clock or Rt resistor?

No-the IR3623MPBF requires either an external Rt resistor connected to Pin 30 (GND) or an external clock signal applied to Pin 23 (Sync) to establish switching frequency. Without either, the oscillator remains inactive and no PWM outputs are generated. The device has no internal default frequency; operation is fully dependent on external timing configuration.

How does the IR3623MPBF handle pre-biased outputs during startup?

The IR3623MPBF supports pre-bias start-up by disabling high-side MOSFET turn-on until the feedback voltage rises above the reference threshold. This prevents reverse current flow into a pre-charged output capacitor. The feature is enabled automatically and requires no external configuration-ensuring safe startup into existing bus voltages without damaging downstream components or causing inrush transients.

What is the function of the Seq pin, and how is it used in sequencing?

The Seq pin (Pin 24) acts as the master enable for tracking and sequencing functions. When pulled high, it activates the Track1/Track2-controlled sequencing behavior (ratiometric or simultaneous). When held low, sequencing is disabled and both outputs operate independently. Its logic threshold is 2.0 V (on) / 0.3 V (off), allowing direct interface with standard GPIO or supervisor IC outputs.