Monolithic Power Systems Inc. MPM3551CGQWE-AEC1-Z

Overview

MPM3551CGQWE-AEC1-Z from Monolithic Power Systems is a fully integrated, AEC-Q100 Grade 1 qualified synchronous step-down power module with embedded 1µH inductor and MOSFETs, delivering up to 3A continuous output current across a 3.3V–36V input range, featuring 42V load dump tolerance, 1µA shutdown quiescent current, and 2.2MHz fixed switching frequency - deployed in automotive infotainment and ADAS domain controllers.

For engineers reviewing the MPM3551CGQWE-AEC1-Z datasheet, MPM3551CGQWE-AEC1-Z pinout, MPM3551CGQWE-AEC1-Z application, or MPM3551CGQWE-AEC1-Z equivalent, key selection criteria include cold-crank support down to 3.1V VIN, CISPR25 Class 5 EMI compliance, wettable-flank QFN-20 package for automated optical inspection, and integrated PG signal with ±5.5% voltage window detection.

Technical Context

The device implements a current-mode controlled synchronous buck architecture with integrated 70mΩ HS-FET and 50mΩ LS-FET, enabling high-efficiency regulation under wide input transients. Its 65ns minimum on-time and 50ns minimum off-time support high duty-cycle operation during automotive cold-crank (VIN as low as 3.1V) while maintaining stable 2.2MHz switching.

Frequency spread spectrum (FSS) modulation ±10% around 2.2MHz, symmetric VIN pinout, and MeshConnect™ flip-chip packaging jointly suppress conducted and radiated EMI to meet CISPR25 Class 5 requirements without external filters. Thermal shutdown at 160°C–185°C and hiccup-mode over-current protection ensure fault resilience in harsh automotive environments.

Key Specifications

Pinout & Package

MPM3551CGQWE-AEC1-Z is housed in a wettable-flank QFN-20 package (4mm × 6mm), optimized for automated optical inspection (AOI) and robust solder joint reliability in automotive reflow profiles. The exposed thermal pad enhances thermal dissipation to PCB ground planes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down module applications.

Compared with MPM3551CGQWE-AEC1-Z, the MPM3695GQV-AEC1-Z offers higher current and input range but sacrifices integration and ease-of-use, while the TPS62933RQWR trades automotive qualification and surge robustness for smaller size and lower cost in benign environments.

Availability

MPM3551CGQWE-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, and digital instrument clusters requiring stable component supply across extended temperature and voltage transients.

Supply support for MPM3551CGQWE-AEC1-Z 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 and modules, with design centers in the US, China, and Taiwan.

The MPM3551C product line delivers fully integrated, AEC-Q100-qualified DC-DC modules targeting space-constrained automotive subsystems requiring high reliability, low EMI, and seamless cold-crank operation.

FAQ

What is the minimum input voltage required for startup?

The MPM3551CGQWE-AEC1-Z requires a minimum VIN of 3.9V to initiate startup, verified per its UVLO rising threshold specification. Once running, it sustains regulation down to 3.1V VIN in low-dropout mode - critical for automotive cold-crank conditions where battery voltage dips below 6V.

Does this module require an external bootstrap capacitor?

Yes - a 0.1µF ceramic capacitor must be placed between the VBOOT and SW pins to sustain high-side MOSFET gate drive. This capacitor is charged during the low-side conduction phase and is essential for proper HS-FET turn-on; omission causes immediate failure to regulate.

Can the PG pin be left unconnected if not used?

Yes - the PG pin is open-drain and may be safely floated when unused. However, if connected, it requires an external pull-up resistor (typically 10kΩ to 5V or VOUT) to generate a valid logic-high signal; no internal pull-up exists.

How does frequency spread spectrum (FSS) affect EMI performance?

FSS modulates the 2.2MHz switching frequency by ±10% at 15kHz, spreading spectral energy across a 440kHz bandwidth. This reduces peak conducted and radiated emissions by up to 10dB compared to fixed-frequency operation, enabling CISPR25 Class 5 compliance without added filter components.

What is the thermal resistance from junction to case (θJC)?

The measured θJC is 6.1°C/W on a JESD51-7 4-layer PCB. This value reflects heat transfer from die to the exposed thermal pad; actual system-level thermal performance depends on PCB copper area, layer stack-up, and airflow - typical case temperature rise is ≤30°C at 3A/12VIN/5VOUT.

Is the integrated inductor shielded?

Yes - the embedded 1µH inductor is a shielded, molded power inductor with 30mΩ DCR, designed to minimize magnetic coupling to adjacent traces and components. Its construction meets automotive-grade vibration and thermal cycling requirements per AEC-Q200.

What happens during over-current events?

Upon detecting over-current, the device enters hiccup-mode protection: it shuts down for ~3ms, then attempts restart. This limits average power dissipation and prevents thermal runaway. The LS valley current limit is 4.4A typical, and HS peak limit is 5.8A typical - both temperature-compensated.