Monolithic Power Systems Inc. MPQ4321GLE-AEC1-Z

Overview

MPQ4321GLE-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade-1 qualified, synchronous step-down DC/DC converter with integrated 70mΩ high-side and 50mΩ low-side MOSFETs, delivering 1A continuous output current. It operates from 3.3V to 36V input, withstands 42V automotive load dump transients, and features 1μA shutdown current, 350kHz–2.5MHz configurable switching frequency, and power-good monitoring. It serves as a primary power supply for automotive infotainment and ADAS domain controllers under cold-crank and wide-temp conditions.

For engineers reviewing the MPQ4321GLE-AEC1-Z datasheet, MPQ4321GLE-AEC1-Z pinout, MPQ4321GLE-AEC1-Z application, or MPQ4321GLE-AEC1-Z equivalent, key selection criteria include its 42V load dump tolerance, -40°C to +150°C junction temperature rating, QFN-12 (3mm×4mm) wettable flank package, 0.8V feedback reference, and CISPR25 Class 5 EMI compliance in automotive power rail designs.

Technical Context

The MPQ4321GLE-AEC1-Z implements peak current mode control with frequency foldback during startup to prevent inductor current runaway. Its advanced asynchronous mode (AAM) dynamically scales switching frequency under light loads to minimize gate-driving and switching losses-enabling 20μA sleep-mode quiescent current and >90% efficiency at 1mA load with 12V input.

It integrates thermal shutdown (160°C–185°C trip range), hiccup-mode over-current protection, and a dedicated low-dropout mode supporting 3.1V minimum VIN operation during automotive cold-crank. The open-drain PG signal asserts within ±5.5% of nominal VOUT and includes deglitching (70μs rising / 60μs falling).

Key Specifications

Pinout & Package

The MPQ4321GLE-AEC1-Z uses a QFN-12 (3mm × 4mm) package with wettable flanks for automated optical inspection and robust solder-joint reliability in automotive reflow processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4321GDE-AEC1-Z, the MPQ4321GLE-AEC1-Z offers superior thermal performance and AOI-ready wettable flanks; versus LM61480QRNXTQ1, it delivers lower quiescent current, cold-crank capability, and frequency configurability-critical for automotive power architecture flexibility.

Availability

MPQ4321GLE-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment, ADAS camera modules, digital instrument clusters, and industrial telematics units requiring stable component supply across extended temperature and high-reliability automotive environments.

Supply support for MPQ4321GLE-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 for automotive, industrial, and consumer applications.

The MPQ4321 product line targets automotive power conversion with AEC-Q100 qualification, load dump resilience, and ultra-low IQ-designed specifically for next-generation domain controllers and ADAS subsystems demanding compact, robust, and EMI-compliant DC/DC solutions.

FAQ

What is the maximum allowable input voltage for continuous operation?

The MPQ4321GLE-AEC1-Z supports continuous operation up to 36V input. It is rated to survive 42V automotive load dump transients per ISO16750-2 Pulse 5a, but sustained operation above 36V may trigger over-voltage protection (35.5V–40V rising threshold) and cause shutdown.

Does this device require an external bootstrap capacitor?

Yes. A 0.1µF ceramic capacitor must be placed between BOOT and SW pins to provide gate-drive voltage for the high-side MOSFET. This capacitor is charged through an internal diode during the low-side conduction phase and is essential for proper high-side switching.

How is power-good (PG) functionality implemented?

PG is an open-drain output that goes high when VOUT is within 94.5%–105.5% of nominal voltage and low when outside 93%–107%. It includes 70μs rising and 60μs falling deglitch timers to reject noise-induced false triggers, and requires an external pull-up resistor to a valid logic supply.

Can the MPQ4321GLE-AEC1-Z operate during automotive cold-crank conditions?

Yes. It supports minimum input voltage of 3.1V after startup and includes a dedicated low-dropout mode that maintains regulation during cold-crank events. The 98–99.5% maximum duty cycle enables high VIN-to-VOUT conversion ratios essential for 12V systems dropping to 3.1V.

What is the purpose of the FREQ pin, and how is frequency set?

The FREQ pin sets switching frequency by connecting an external resistor to ground. Typical values include 86.6kΩ for ~415kHz, 34.8kΩ for ~1MHz, and 15kΩ for ~2.2MHz. Frequency scaling under light load (via AAM) further optimizes efficiency without user intervention.

Is the QFN-12 (3mm×4mm) package lead-free and RoHS-compliant?

Yes. The MPQ4321GLE-AEC1-Z is fully lead-free, halogen-free, and complies with the RoHS directive. MPS confirms green status per its Quality Assurance documentation, and the wettable flank plating supports standard Pb-free reflow profiles.

How does the device handle over-current conditions?

It employs hiccup-mode over-current protection: upon detecting peak switch current exceeding 1.5A–2.6A or valley current below 1A–1.5A, the device disables switching, waits a fixed interval, then attempts restart. This prevents thermal damage during sustained shorts while enabling automatic recovery.