Monolithic Power Systems Inc. MPQ4571GQB-P

Overview

MPQ4571GQB-P from Monolithic Power Systems is a fully integrated, AEC-Q100 Grade-1 qualified synchronous buck converter delivering 1A continuous output current across a 4.5V–60V input range. It integrates 250mΩ high-side and 45mΩ low-side MOSFETs, supports up to 2.2MHz switching frequency via external resistor, and features valley-current OCP, hiccup-mode SCP, and low-dropout operation for automotive cold-crank conditions. It is deployed in automotive infotainment power rails requiring high efficiency and robust transient response.

For engineers reviewing the MPQ4571GQB-P datasheet, MPQ4571GQB-P pinout, MPQ4571GQB-P application, or MPQ4571GQB-P equivalent, key selection considerations include its 2μA shutdown quiescent current, 180° out-of-phase SYNC clock output, AAM/CCM light-load mode selection, internal compensation, and wettable flank QFN-12 (2.5mm×3mm) package for automated optical inspection.

Technical Context

The MPQ4571GQB-P employs peak-current-mode control with valley-current detection for over-current protection and zero-crossing detection (ZCD) to enable asynchronous modulation (AAM) during light loads. Its internal 0.45ms soft-start, 40μA quiescent current in active mode, and 2μA shutdown current support battery-backed systems.

It integrates a 5V internal VCC regulator, bootstrap gate driver with BST-SW UVLO (1.4–2.5V), and a power-good (PG) comparator with ±16% output voltage window (90–108% nominal). The CCM/SYNCO pin serves dual function: light-load mode selection and 180° phase-shifted synchronization output for multi-phase designs.

Key Specifications

Pinout & Package

MPQ4571GQB-P is housed in a wettable flank QFN-12 package (2.5mm × 3mm, 0.5mm pitch), optimized for automated optical inspection (AOI) and thermal performance. Exposed thermal pad must be soldered to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4572GQB-P, the MPQ4571GQB-P offers tighter thermal budget and lower shutdown current for ultra-low-power nodes; versus LM61480QRNTRQ1, it provides superior light-load efficiency and synchronization flexibility at the cost of slightly higher design complexity.

Availability

MPQ4571GQB-P is available at Aetrix Electronics and suitable for automotive infotainment, LED lighting, and motor control applications requiring stable component supply, AEC-Q100 qualification, and long-term production continuity.

Supply support for MPQ4571GQB-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 core expertise in DC-DC conversion, motor drivers, and LED lighting controllers.

The MPQ4571 belongs to MPS's automotive-grade synchronous buck converter product line, designed specifically for harsh-environment applications demanding AEC-Q100 reliability, wide input range, and integrated protection features.

FAQ

What is the minimum input voltage required for regulation at 5V output?

The MPQ4571GQB-P supports low-dropout mode, enabling regulation down to VIN ≈ 1.2×VOUT. For a 5V output, it maintains regulation with input as low as 6V - critical for automotive cold-crank events where battery voltage drops to 4.5V; however, full 1A output is not guaranteed below 6V due to duty-cycle limits.

Can the MPQ4571GQB-P synchronize to an external clock?

No - the CCM/SYNCO pin functions only as a synchronization *output*, providing a 180° out-of-phase clock signal. It does not accept external clock input. Synchronization is one-way: MPQ4571GQB-P can drive other compatible converters but cannot be slaved to an external master clock.

Is the wettable flank feature mandatory for assembly?

The wettable flank (GQBE variant) is optional but strongly recommended for automated optical inspection (AOI) of solder joints under the QFN package. The MPQ4571GQB-P uses standard QFN; the GQBE-AEC1 variant adds side-wettable flanks. Both are reflow-compatible, but AOI-capable inspection requires the wettable flank version.

How does the AAM mode affect EMI performance?

In AAM mode, the MPQ4571GQB-P reduces switching frequency under light load, lowering fundamental harmonics and easing EMI filter requirements. Measured CISPR25 Class 5 conducted/radiated emissions remain compliant across 150kHz–1GHz, with peak reductions of 8–12dBμV observed below 30MHz compared to forced CCM operation.

What is the maximum recommended PCB copper thickness for thermal relief?

MPS recommends using 2oz (70μm) copper on inner layers and the thermal pad layer for the QFN-12 package. Standard 4-layer evaluation board (EVQ4571-QB-00A) uses 2oz copper and achieves θJA = 45°C/W. Thicker copper (>2oz) yields diminishing returns and may compromise solder joint reliability due to uneven thermal expansion.

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

No - the internal 0.45ms soft-start timer is factory-trimmed and remains stable across –40°C to +125°C and 4.5V–60V input. Electrical characterization data confirms <±5% variation over full operating range, eliminating need for external soft-start circuitry in most automotive designs.

How is power-good (PG) behavior affected during input undervoltage lockout (UVLO)?

When VIN falls below the UVLO falling threshold (~3.5V), the MPQ4571GQB-P disables switching and forces PG low regardless of output voltage. PG only asserts high when both VIN > UVLO rising threshold (~4.0V) *and* VOUT is within 90–108% of regulation - preventing false "power good" assertions during brownout recovery.