Monolithic Power Systems Inc. MP4571GQB-P

Overview

MP4571GQB-P from Monolithic Power Systems is a fully integrated, synchronous step-down DC-DC converter with 4.5V–60V input range, 1A continuous output current, and internal 250mΩ/45mΩ high-side/low-side MOSFETs. It delivers automotive-grade reliability with cold-crank low-dropout mode, hiccup short-circuit protection, and ±1% FB reference accuracy at room temperature-deployed in infotainment power rails and LED lamp drivers.

For engineers reviewing the MP4571GQB-P datasheet, MP4571GQB-P pinout, MP4571GQB-P application, or MP4571GQB-P equivalent, key selection criteria include VIN UVLO threshold (4.0V typ), 2μA shutdown quiescent current, AAM/CCM light-load mode selection, and QFN-12 (2.5mm×3mm) wettable flank package compatibility with automated optical inspection.

Technical Context

The MP4571GQB-P employs peak-current-mode control with valley-current overcurrent detection and asynchronous modulation (AAM) for light-load efficiency scaling. Its internal compensation network eliminates external loop components, while the 180° out-of-phase SYNCO clock enables multi-phase synchronization without external timing ICs.

It integrates a 0.45ms internal soft-start, power-good indicator with 90–108% VREF window, and dual protection logic: thermal shutdown at 170°C with 25°C hysteresis and hiccup-mode SCP triggered by valley-current limit violation. The BST bootstrap circuit supports high-duty-cycle operation down to 4.5V input during cold-crank events.

Key Specifications

Pinout & Package

MP4571GQB-P is housed in a wettable flank QFN-12 package (2.5mm × 3mm, 0.5mm pitch), optimized for solder joint inspection and thermal performance. Exposed thermal pad must be connected to PCB ground plane for θJA = 45°C/W on standard 4-layer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4571GQB-A, the MP4571GQB-P omits AEC-Q100 documentation but matches all electrical, thermal, and mechanical specs-ideal for non-safety automotive subsystems. Versus LM61480QRTWRQ1, it trades current capacity for smaller footprint, lower quiescent current, and superior cold-crank behavior.

Availability

MP4571GQB-P is available at Aetrix Electronics and suitable for automotive infotainment, LED lighting, and industrial power systems requiring stable component supply with extended temperature support and wettable flank inspection capability.

Supply support for MP4571GQB-P 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs, with design centers in the US, China, and Taiwan.

The MP4571 product line targets automotive and industrial DC-DC conversion where wide input range, low IQ, and robust protection are essential-designed specifically for harsh environments with rapid transients and extended temperature operation.

FAQ

What is the minimum input voltage for reliable startup?

The MP4571GQB-P starts reliably at 4.5V due to its 4.0V typical UVLO rising threshold with 500mV hysteresis. Below 4.5V, the device enters low-dropout mode to maintain regulation until VIN drops below 3.5V (UVLO falling threshold), enabling operation during automotive cold-crank events.

Can the MP4571GQB-P synchronize to an external clock?

No-the CCM/SYNCO pin functions only as an output providing a 180° out-of-phase clock signal for synchronizing other MP4571 devices. It does not accept external clock inputs; frequency is set solely by the FREQ resistor or internal default.

How is thermal performance affected by NC pins 9 and 10?

Pins 9 and 10 are no-connect but thermally tied to the die paddle. Connecting them to GND improves heat conduction from the package to the PCB, reducing θJA by up to 5°C/W in standard layouts-recommended for continuous 1A operation at ambient >85°C.

Does the internal soft-start time change with input voltage?

No-the 0.45ms soft-start duration is fixed and internally generated, independent of VIN, temperature, or load. It controls the FB reference ramp rate, ensuring consistent inrush current limiting across all operating conditions.

What is the recommended layout practice for the BST capacitor?

Use a 0.1µF X7R 0603 ceramic capacitor placed directly between BST and SW pins with minimal trace length (<1mm). Avoid routing near noisy signals-BST node voltage swings from SW to SW+5V and is sensitive to parasitic inductance.

Is the PG pin compatible with 3.3V logic systems?

Yes-the PG pin is open-drain and requires an external pull-up. Select a pull-up resistor to 3.3V (e.g., 10kΩ) to ensure valid logic levels; sink current capability is 4mA at 300mV drop, sufficient to drive standard microcontroller GPIO inputs.

How does AAM mode affect conducted EMI performance?

AAM reduces switching frequency under light load, lowering fundamental EMI energy and shifting harmonics away from sensitive bands like AM radio (530–1710kHz). Measured CISPR25 Class 5 emissions show >10dB improvement in 150kHz–30MHz range versus forced CCM at 10mA load.