Infineon Technologies IR3800MTR1PBF

Overview

IR3800MTR1PBF from Infineon Technologies is a highly integrated synchronous buck regulator with on-die high- and low-side MOSFETs, 600 kHz fixed-frequency PWM control, 0.6 V reference accuracy (±2%), 12 A continuous output current capability, and wide 2.5–21 V input range-designed for point-of-load regulation in graphics cards and embedded computing systems.

For engineers reviewing the IR3800MTR1PBF datasheet, IR3800MTR1PBF pinout, IR3800MTR1PBF application, or IR3800MTR1PBF equivalent, key selection considerations include its programmable hiccup over-current protection, pre-bias start-up support, thermal shutdown with 20°C hysteresis, and dual-supply UVLO thresholds for VCC (4.4 V turn-on) and VC (3.5 V turn-on).

Technical Context

The IR3800MTR1PBF implements voltage-mode PWM control using an internal 600 kHz oscillator and linear sawtooth ramp generator, eliminating external timing components. Its error amplifier compares FB voltage against a precision 0.6 V internal reference and drives COMP to modulate duty cycle via trailing-edge PWM.

Current limiting is achieved by sensing R_DS(on) of the integrated low-side MOSFET (6.9–8.7 mΩ), enabling resistor-programmable OCSET threshold without external sense resistors. Dual independent UVLO circuits monitor VCC and VC supplies, with separate rising/falling thresholds and hysteresis to prevent chatter during brown-out conditions.

Key Specifications

Pinout & Package

15-pin thermally enhanced Power QFN package (5 mm × 6 mm), exposed thermal pad on underside for direct PCB copper connection and efficient heat dissipation.

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 TPS54620RGYR, the IR3800MTR1PBF delivers full 12 A integration in a single 5×6 mm QFN, eliminates external sense resistors via R_DS(on) current sensing, and provides dual-supply UVLO and pre-bias start-up-making it optimal for space-constrained, high-reliability computing PoL applications.

Availability

IR3800MTR1PBF is available at Aetrix Electronics and suitable for graphics card VRMs, desktop PC CPU core supplies, and embedded SoC power delivery requiring stable component supply, RoHS-compliant packaging, and production-ready thermal performance.

Supply support for IR3800MTR1PBF 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 GaN-based power stages.

The IR3800 belongs to Infineon's SupIRBuck™ family-designed specifically for high-current, space-constrained point-of-load regulation in computing, gaming, and consumer electronics where integration, thermal efficiency, and reliability are critical.

FAQ

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

The IR3800MTR1PBF requires ≥100 µF total ceramic output capacitance (X5R/X7R, 6.3 V rating) placed near the SW and PGnd pins. Layout must minimize loop inductance; typical designs use four 22 µF or six 10 µF 0805/1206 devices with low-ESR construction to meet transient response and ripple targets under full load.

How does the OCSet pin implement hiccup-mode current limiting?

The OCSet pin draws a fixed current (15–28 µA) that develops a voltage across an external resistor tied to SW. When sensed current exceeds the threshold, the device enters hiccup mode: it shuts down for ~10 ms, then attempts restart. This cycle repeats until fault clears, preventing thermal runaway during sustained overloads or shorts.

Can the IR3800MTR1PBF operate with a 3.3 V input supply?

No-the absolute minimum VIN is 2.5 V, but the recommended operating range starts at 4.5 V per datasheet Section 5. At 3.3 V, VCC UVLO (4.0 V turn-on) and VC UVLO (3.1 V turn-on) prevent functional operation; the device remains latched off even if VIN rises above 3.3 V until both supplies exceed their respective thresholds.

Is the AGnd–PGnd separation mandatory, and what happens if they are shorted?

Yes-AGnd (pins 4, 5, 15) and PGnd (pin 10) must be separated on the PCB and joined only at a single point near the IC's thermal pad. Shorting them directly introduces high di/dt switching noise into analog reference and error amplifier paths, causing output voltage instability, increased ripple (>50 mV), and potential false over-current triggering.