Infineon Technologies IRU3037ACSTR

Overview

IRU3037ACSTR from Infineon Technologies is a fixed-frequency, voltage-mode synchronous PWM controller IC for buck DC-DC conversion in DDR memory Vtt source/sink and low-voltage on-board power supplies (e.g., 5V-to-1.8V). It features a 400 kHz internal oscillator, 500 mA peak gate drive, under-voltage lockout (UVLO) on Vcc (4.2 V threshold) and Vc (3.3 V threshold), programmable soft-start, and output undervoltage latch-off at 0.4 V - enabling robust 3+ A load regulation in graphic cards and HDDs.

For engineers reviewing the IRU3037ACSTR datasheet, IRU3037ACSTR pinout, IRU3037ACSTR application, or IRU3037ACSTR equivalent, key selection criteria include switching frequency (400 kHz), UVLO thresholds, Fb reference voltage (0.800 V), soft-start charge current (2 µA), and SOIC-8 lead-free package compatibility with high-side/lower-side N-MOSFET gate drive requirements.

Technical Context

The IRU3037ACSTR implements voltage-mode PWM control using a precision 0.800 V internal reference and error amplifier with transconductance of 64 µmho. Its 400 kHz oscillator sets fixed timing, independent of input/output conditions, and drives complementary high-side (HDrv) and low-side (LDrv) outputs with 150 ns typical dead time to prevent shoot-through.

Protection logic includes dual-rail UVLO (Vcc & Vc), output undervoltage detection (latches off below 0.4 V), and short-circuit response via Fb monitoring. The SS/SD pin enables both programmable soft-start (via external capacitor) and active shutdown (pull <0.5 V), while Comp supports loop compensation with external R-C network.

Key Specifications

Pinout & Package

IRU3037ACSTR is housed in an 8-pin SOIC NB (Small Outline Integrated Circuit, Narrow Body) package, Pb-free, with standard 1.27 mm pitch and 5.0 mm × 6.2 mm footprint. Thermal resistance θ_JA = 124°C/W enables operation up to 125°C junction temperature under typical PCB copper pour.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2307DN-LF-Z and TPS54332DR, the IRU3037ACSTR offers superior fault resilience (dual UVLO + latch-off), higher peak drive (500 mA vs ≤300 mA), and dedicated Vc rail for optimized high-side gate control - critical for >3 A DDR and graphics applications where reliability trumps integration density.

Availability

IRU3037ACSTR is available at Aetrix Electronics and suitable for DDR memory Vtt regulation, graphics card core power, and industrial FPGA I/O bank power requiring stable component supply across automotive-grade temperature ranges (0°C to 70°C operating).

Supply support for IRU3037ACSTR 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 global manufacturing and quality certification to ISO/TS 16949.

The IRU3037A product line delivers cost-optimized, discrete-gate-driver-based synchronous buck controllers targeting high-current, low-voltage DC-DC conversion in memory, storage, and computing infrastructure.

FAQ

What is the function of the Vc pin on the IRU3037ACSTR?

The Vc pin supplies power to the high-side gate driver and must be ≥4 V above the output bus voltage (e.g., 9 V for a 5 V output). It requires a minimum 1 µF high-frequency ceramic capacitor to ground to sustain peak drive current. Unlike Vcc, Vc has its own UVLO (3.3 V threshold) to prevent unsafe high-side activation during boost supply faults.

How does the IRU3037ACSTR achieve output undervoltage protection?

The IRU3037ACSTR continuously monitors the Fb pin voltage. If Fb drops below 0.4 V - indicating output collapse due to short-circuit or feedback failure - the device latches off both HDrv and LDrv outputs permanently until power-cycled. This differs from cycle-by-cycle current limiting and provides definitive fault containment.

Can the IRU3037ACSTR operate with only a 5 V input supply?

Yes. The IRU3037ACSTR operates with single 5 V or 12 V Vcc supply. For 5 V input, Vc must be derived separately (e.g., via charge pump or auxiliary rail) since it must exceed the output bus by ≥4 V. Example: For 1.8 V output, Vc ≥ 5.8 V - achievable with a 6.3 V charge-pump capacitor or dedicated 6 V LDO.

What is the significance of the 400 kHz oscillator frequency in system design?

The 400 kHz oscillator fixes the switching period at 2.5 µs, directly determining inductor ripple current (∆i ∝ 1/f_SW) and output capacitor ESR requirements. Higher frequency allows smaller magnetics and lower output ripple but increases switching losses - making 400 kHz optimal for balancing size, efficiency, and thermal performance in 3–4 A applications.