Monolithic Power Systems Inc. MPQ4323CGRHE-33-AEC1-Z

Overview

MPQ4323CGRHE-33-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous step-down DC/DC converter delivering 3A continuous output current with integrated 70mΩ high-side and 50mΩ low-side MOSFETs. It operates from 3.3V to 36V input, withstands 42V automotive load dump, supports cold-crank down to 3.1V, and features configurable switching frequency (350kHz–2.5MHz) for EMI optimization in automotive infotainment and ADAS power rails.

For engineers reviewing the MPQ4323CGRHE-33-AEC1-Z datasheet, MPQ4323CGRHE-33-AEC1-Z pinout, MPQ4323CGRHE-33-AEC1-Z application, or MPQ4323CGRHE-33-AEC1-Z equivalent, key selection criteria include its 42V load-dump tolerance, 1μA shutdown quiescent current, QFN-14 (2.5mm×3.5mm) wettable-flank package, CISPR25 Class 5 compliance, and fixed 3.3V output version with power-good monitoring.

Technical Context

The MPQ4323CGRHE-33-AEC1-Z employs peak current mode control with frequency foldback during start-up to prevent inductor current runaway. Its internal gate drivers support a minimum on-time of 65ns and off-time of 50ns, enabling high duty-cycle operation for automotive cold-crank conditions (VIN ≥ 3.1V) while maintaining regulation at VOUT = 3.3V.

It integrates a precision 0.8V reference with ±1% FB voltage accuracy over temperature, open-drain PG output with 94.5%–105.5% window detection, and hiccup-mode over-current protection triggered at 4.4A valley current limit. Thermal shutdown activates at 175°C with 20°C hysteresis for fault-tolerant operation.

Key Specifications

Pinout & Package

MPQ4323CGRHE-33-AEC1-Z uses a QFN-14 (2.5mm × 3.5mm) package with wettable flanks for automated optical inspection (AOI) and enhanced solder joint reliability in automotive production. The exposed thermal pad must be connected to a dedicated GND plane for optimal thermal performance (θJC = 3.6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4323CGDE-AEC1-Z, this QFN-14 variant offers 7% lower thermal resistance and 5% higher power handling; versus TPS62933RQWR, it delivers certified automotive robustness at the expense of wider input range flexibility.

Availability

MPQ4323CGRHE-33-AEC1-Z is available at Aetrix Electronics and suitable for automotive infotainment, instrument clusters, ADAS camera modules, and telematics systems requiring stable component supply with full AEC-Q100 Grade 1 traceability and PPAP documentation.

Supply support for MPQ4323CGRHE-33-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, with over two decades of leadership in DC/DC conversion, motor drivers, and LED lighting solutions.

The MPQ4323C product line targets automotive power systems requiring AEC-Q100 qualification, load dump resilience, and compact footprint - designed specifically for next-generation domain controllers and zonal architectures.

FAQ

What is the maximum allowable input voltage transient the MPQ4323CGRHE-33-AEC1-Z can survive?

The device is rated for 42V load dump per ISO 16750-2 Pulse 5a, with absolute maximum VIN = +42V. It sustains this transient without latch-up, parameter shift, or degradation when used with recommended input capacitance (≥47µF ceramic + bulk electrolytic) and proper PCB layout.

Does the fixed 3.3V output version support external feedback adjustment?

No. MPQ4323CGRHE-33-AEC1-Z has internal resistor divider hardwired to 3.3V; the FB pin is not accessible. For adjustable output, select MPQ4323CGRHE-AEC1-Z and use external resistors between FB, VOUT, and AGND per datasheet Figure 2.

How is the power-good (PG) signal configured for system monitoring?

PG is an open-drain output requiring an external pull-up resistor (typically 10kΩ to 3.3V or 5V). It asserts high when VOUT is within 94.5%–105.5% of 3.3V and pulls low outside that window, with 70µs rising and 60µs falling deglitch timing to reject noise.

Can the MPQ4323CGRHE-33-AEC1-Z operate in forced continuous conduction mode (FCCM)?

Yes. FCCM is enabled by pulling the MODE pin (not present on this fixed-output variant) high - however, MPQ4323CGRHE-33-AEC1-Z defaults to automatic PFM/FCCM transition. At light loads (<100mA), it enters diode-emulation mode to maintain regulation while minimizing IQ.

What thermal performance can be expected with the QFN-14 package on a 4-layer board?

On an MPS-recommended 4-layer EVB (2oz copper, 8.3cm×8.3cm), junction-to-ambient thermal resistance is 33.6°C/W. At 3A/12VIN/3.3VOUT, case temperature rise is ~24°C above ambient - enabling full-rated output without active cooling below 105°C ambient.

Is spread-spectrum frequency modulation (FSS) enabled by default?

Yes. FSS is active at all frequencies and cannot be disabled. It provides ±10% frequency deviation at 15kHz modulation rate, reducing peak EMI by up to 10dB and easing CISPR25 Class 5 compliance without additional filtering.

What is the minimum input voltage required to sustain 3.3V output at 3A load?

Under cold-crank conditions, the device maintains regulation down to VIN = 3.4V at 3A (measured at TJ = 125°C). Below this, dropout mode engages - VOUT tracks VIN minus RDS(ON) × IOUT, preserving partial functionality during engine start.