Monolithic Power Systems Inc. MPQ4321CGRHE-AEC1-P

Overview

MPQ4321CGRHE-AEC1-P from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous step-down DC/DC converter with integrated 70mΩ/50mΩ HS/LS MOSFETs, 3.3V–36V input range, 42V load dump tolerance, and configurable 350kHz–2.5MHz switching frequency. It delivers up to 1A continuous output current with 1μA shutdown current and operates across –40°C to +150°C junction temperature - deployed in automotive infotainment power rails.

For engineers reviewing the MPQ4321CGRHE-AEC1-P datasheet, MPQ4321CGRHE-AEC1-P pinout, MPQ4321CGRHE-AEC1-P application, or MPQ4321CGRHE-AEC1-P equivalent, key selection considerations include cold-crank support (3.1V min VIN), CISPR25 Class 5 EMI compliance, wettable flank QFN-14 package for automated optical inspection, and programmable frequency via external resistor.

Technical Context

The MPQ4321C employs peak current-mode control with frequency foldback during startup to prevent inductor current runaway. Its MeshConnect™ flip-chip QFN-14 package enables symmetric VIN pinout and low-inductance layout for EMI reduction.

It integrates dual protection modes: hiccup-mode over-current protection and thermal shutdown at 160°C–185°C with 20°C hysteresis. Low-dropout (LDO) mode and high duty cycle (98–99.5%) support automotive cold-crank conditions where input drops to 3.1V while maintaining regulated output.

Key Specifications

Pinout & Package

MPQ4321CGRHE-AEC1-P uses a wettable flank QFN-14 (2.5mm × 3.5mm) package with exposed thermal pad. Pin 1 is marked by a dot; pins are arranged in two rows (7 per side), with NC pins at positions 2 and 12.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4321CGDE-AEC1-P, the MPQ4321CGRHE-AEC1-P offers superior thermal performance (θJA = 48.6°C/W) and AOI-ready wettable flanks, while LM61480QRNXTQ1 trades EMI simplicity for raw current capability - making the RHE variant optimal for compact, production-ready automotive modules.

Availability

MPQ4321CGRHE-AEC1-P is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS ECUs, and instrument clusters requiring stable component supply with AEC-Q100 Grade 1 assurance and full traceability.

Supply support for MPQ4321CGRHE-AEC1-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 for automotive, industrial, and consumer markets.

The MPQ4321C product line targets automotive power conversion with emphasis on AEC-Q100 compliance, load dump resilience, and EMI robustness - designed specifically for next-generation vehicle electronics demanding small size, high reliability, and simplified certification.

FAQ

What is the minimum input voltage required to start up the MPQ4321CGRHE-AEC1-P?

The device requires a minimum input voltage of 3.9V to initiate startup due to its UVLO rising threshold of 3.4–3.9V. Once running, it sustains regulation down to 3.1V via low-dropout mode - essential for automotive cranking conditions where battery voltage collapses temporarily.

Does MPQ4321CGRHE-AEC1-P support adjustable output voltage?

Yes. The FB pin accepts an external resistive divider to set output voltage from 0.8V to 0.95×VIN. The internal reference is tightly regulated at 0.794–0.806V (25°C), with ±0.01V drift over –40°C to +150°C, enabling precise 3.3V or 5V generation without external error amplifiers.

How does the frequency spread spectrum (FSS) function reduce EMI?

FSS modulates switching frequency by ±10% at 15kHz, spreading energy across a bandwidth instead of concentrating at discrete harmonics. This lowers peak conducted and radiated emissions, allowing the device to meet CISPR25 Class 5 limits without additional ferrite beads or common-mode chokes in typical layouts.

What is the purpose of the NC pins on the QFN-14 package?

Pins 2 and 12 are not internally connected. They may be left floating or tied to PGND to improve mechanical anchoring and thermal conduction to the PCB. Neither connection affects electrical performance, but grounding them enhances solder joint reliability during reflow and thermal cycling.

Can MPQ4321CGRHE-AEC1-P operate in forced continuous conduction mode (FCCM)?

Yes. FCCM is enabled by default and prevents discontinuous conduction mode (DCM) at light loads. This ensures constant switching frequency, stable loop response, and predictable EMI behavior - critical for timing-sensitive automotive subsystems where variable-frequency operation could interfere with CAN or LIN bus signaling.

What thermal metrics define the QFN-14 package's performance?

The QFN-14 (2.5mm×3.5mm) variant has θJA = 48.6°C/W (JEDEC JESD51-7, 4-layer board) and θJC = 7.4°C/W (junction-to-case bottom). At 1A load and 12V input, typical case temperature rise is <10°C - enabling operation without heatsinks in most automotive under-hood or cabin environments.

Is the PG signal compatible with 1.8V or 3.3V logic interfaces?

Yes. The PG pin is an open-drain output rated for 5.5V max. When pulled up to any logic supply (1.8V, 3.3V, or 5V), it sinks ≤1mA at 0.3V low level - ensuring clean interfacing with modern low-voltage MCUs and FPGAs without level-shifting circuitry.