Monolithic Power Systems Inc. MP4322GDE-P

Overview

MP4322GDE-P from Monolithic Power Systems is a 36V input, 2A synchronous step-down DC/DC converter with integrated 70mΩ/50mΩ HS/LS MOSFETs, configurable switching frequency (350kHz–2.5MHz), 42V load dump tolerance, and 1μA shutdown current. It delivers high efficiency across load range via frequency foldback and AAM light-load mode, and supports automotive cold-crank down to 3.1V VIN. Used in USB chargers and aftermarket automotive power rails.

For engineers reviewing the MP4322GDE-P datasheet, MP4322GDE-P pinout, MP4322GDE-P application, or MP4322GDE-P equivalent, key selection criteria include 42V transient tolerance, wettable-flank QFN-12 package for solder inspection, ±1.5% PG threshold accuracy, 65ns minimum on-time for high VIN-to-VOUT ratios, and CISPR25 Class 5 EMI compliance with FSS modulation.

Technical Context

The MP4322GDE-P employs peak current mode control with frequency foldback during startup to prevent inductor current runaway. Its asymmetric VIN pinout (pins 2 & 10) and symmetric layout reduce high-frequency loop area, while MeshConnect™ flip-chip packaging improves thermal resistance (θJC = 7.3°C/W) and EMC performance.

It integrates dual protection schemes: hiccup-mode over-current protection triggered at 2.7–4.6A HS peak current and thermal shutdown at 160–185°C with 20°C hysteresis. The LDO mode enables continuous regulation when VIN drops near VOUT, critical for automotive cold-crank operation.

Key Specifications

Pinout & Package

MP4322GDE-P is housed in a wettable flank QFN-12 package (2mm × 3mm, 0.5mm pitch), enabling automated optical solder-joint inspection. Thermal pad (exposed die attach) connects to PGND for low-impedance heat path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480RQWR and TPS543B20RTWT, MP4322GDE-P uniquely combines 42V load dump tolerance, wettable flank packaging, and CISPR25 Class 5 compliance in a 2A solution-making it optimal for cost-sensitive, safety-critical automotive aftermarket designs where board-level reliability verification is mandatory.

Availability

MP4322GDE-P is available at Aetrix Electronics and suitable for USB chargers, aftermarket telematics modules, and industrial CAN bus nodes requiring stable component supply across extended temperature and transient-voltage conditions.

Supply support for MP4322GDE-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 design centers in the US, China, and Taiwan.

The MP4322 belongs to MPS's automotive-qualified DC/DC converter product line, engineered specifically for harsh-environment aftermarket applications demanding load dump resilience, ultra-low IQ, and AEC-Q100 alignment (though not certified).

FAQ

What is the minimum input voltage required to maintain regulation during cold-crank?

The MP4322GDE-P sustains regulation down to 3.1V input after startup, enabled by its low-dropout (LDO) mode. This meets automotive cold-crank specifications where battery voltage dips below 6V for extended periods. UVLO falling threshold is 2.9V typical, ensuring reliable restart once voltage recovers.

Does MP4322GDE-P require an external bootstrap capacitor?

Yes - a 0.1μF X7R ceramic capacitor must be placed directly between BOOT and SW pins. This capacitor supplies gate drive energy for the high-side MOSFET during each switching cycle. Placement must be adjacent to the IC with minimal trace length to avoid ringing and gate drive instability.

How is the switching frequency set, and what resistor values correspond to common frequencies?

Switching frequency is set by connecting a resistor from FREQ pin to AGND. Typical values: 86.6kΩ → 415kHz, 34.8kΩ → 1.0MHz, and 15kΩ → 2.2MHz. Frequency varies ±10% with FSS modulation active, reducing EMI peak amplitudes by spreading energy across a band.

Can MP4322GDE-P operate without the PG pin connected?

Yes - the PG pin is open-drain and may be left floating if power-good monitoring is not required. When used, it must be pulled up externally (e.g., to 3.3V or 5V) with a 10kΩ resistor. PG asserts high when VOUT is within 94.5–105.5% of target, providing precise rail validation for system sequencers.

What thermal performance can be expected on a standard 2-layer PCB?

On a 2-layer board (1oz copper), θJA rises to ~95°C/W. At 2A load and 12V input, junction temperature may exceed 125°C ambient limit without heatsinking. For production use, MPS recommends a 4-layer board with internal ground/power planes and thermal vias under the exposed pad to achieve rated 125°C operation.

Is the MP4322GDE-P RoHS and halogen-free compliant?

Yes - MP4322GDE-P is lead-free, halogen-free, and fully compliant with the EU RoHS Directive 2011/65/EU. All plating and molding compounds meet MPS's green materials policy, and full compliance documentation is available via the MPS Quality Assurance portal.

Does the device support adjustable output voltage, and what is the feedback reference voltage?

Yes - MP4322GDE-P supports adjustable output via external resistor divider on FB pin. The internal reference is 0.800V ±1%, specified over -40°C to +125°C. For fixed-output variants (e.g., MP4322GQD-33), FB is internally tied to VOUT and the pin is not accessible.