Monolithic Power Systems Inc. MP4323CGRHE-P

Overview

MP4323CGRHE-P from Monolithic Power Systems is a 42V load-dump-tolerant, 3A synchronous step-down DC/DC converter with integrated 70mΩ high-side and 50mΩ low-side MOSFETs, configurable 350kHz–2.5MHz switching frequency, and operation across 3.3V–36V input range. It delivers regulated output in automotive aftermarket USB chargers and cold-crank battery-powered systems, featuring 1μA shutdown current and power-good monitoring.

For engineers reviewing the MP4323CGRHE-P datasheet, MP4323CGRHE-P pinout, MP4323CGRHE-P application, or MP4323CGRHE-P equivalent, key selection criteria include 42V transient survivability, QFN-14 wettable-flank package for automated optical inspection, CISPR25 Class 5 EMI compliance, and thermal performance up to +150°C junction temperature in compact 2.5mm×3.5mm footprint.

Technical Context

The MP4323CGRHE-P employs peak current mode control with frequency foldback during startup to prevent inductor current runaway. Its dual VIN pins and symmetric VIN pinout reduce PCB loop inductance and improve conducted EMI performance.

It integrates a 5V internal LDO (VCC) with 50mA current limit, supports forced continuous conduction mode (FCCM), and features low-dropout operation down to 3.1V input for automotive cold-crank conditions - enabled by high duty cycle capability and hiccup-mode over-current protection.

Key Specifications

Pinout & Package

MP4323CGRHE-P is housed in a thermally enhanced QFN-14 (2.5mm × 3.5mm) package with wettable flanks for solder joint inspection. The package features exposed thermal pad (EP) connected to PGND internally and requires PCB thermal vias for optimal junction-to-board heat transfer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480RQWR and TPS543320RTWR, MP4323CGRHE-P offers superior automotive transient resilience (42V load dump + 3.1V cold crank), smaller QFN-14 footprint, and integrated EMI mitigation - making it optimal for space-constrained, cost-sensitive aftermarket modules where analog simplicity and AOI compatibility are critical.

Availability

MP4323CGRHE-P is available at Aetrix Electronics and suitable for USB chargers, aftermarket automotive modules, and battery-powered systems requiring stable component supply with full automotive-grade qualification and long-term lifecycle support.

Supply support for MP4323CGRHE-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 core expertise in DC/DC converters, motor drivers, and LED drivers for automotive, industrial, and consumer markets.

The MP4323C product line is designed specifically for ruggedized automotive aftermarket applications - emphasizing transient survivability, compact packaging, and EMI robustness without requiring complex external circuitry or digital interfaces.

FAQ

What is the minimum input voltage required for startup and sustained operation?

The MP4323CGRHE-P requires a minimum 3.9V input to initiate startup (VIN UVLO rising threshold), but sustains regulation down to 3.1V after startup (VIN UVLO falling threshold), enabling reliable operation during automotive cold-crank events where battery voltage dips below 6V.

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

Switching frequency is set by connecting an external resistor from FREQ pin to GND. Typical values: 86.6kΩ yields 415kHz, 34.8kΩ yields 1MHz, and 15kΩ yields 2.2MHz. Frequency tolerance is ±15% over temperature and process variation, with ±10% spread-spectrum modulation applied.

Does the MP4323CGRHE-P support both adjustable and fixed-output versions?

MP4323CGRHE-P is the adjustable-output variant, using external resistive feedback on the FB pin. Fixed-output versions (e.g., MP4323CGQHE-P for 3.3V or 5V) exist but require different part numbers and have FB internally connected to the output divider - they are not pin-compatible with the GRHE-P variant.

What thermal performance can be expected in a standard 4-layer PCB layout?

On an MPS-recommended 4-layer evaluation board (8.3cm × 8.3cm, 2oz copper), θJA is 33.6°C/W and θJC is 3.6°C/W. At 3A load and 12V input, case temperature rise is typically <25°C above ambient - enabling full-rated output without forced airflow in most enclosed automotive housings.

Is the PG (power-good) signal actively driven or open-drain, and what pull-up is recommended?

The PG pin is strictly open-drain and requires an external pull-up resistor. A 10kΩ to 100kΩ resistor to VOUT or VCC is recommended; lower values improve noise immunity but increase static current. PG asserts high when VOUT is within 94.5%–105.5% of nominal and pulls low outside that window with 70µs rising / 60µs falling deglitch timing.

Can the NC pins (2 and 12) be left floating, or should they be grounded?

Pins 2 and 12 are designated NC (no connection) and are not bonded internally. They may be left floating, but grounding them improves mechanical stability and provides additional thermal conduction paths to the PGND plane - recommended practice for automotive vibration environments and thermal performance optimization.

What protection features are implemented, and how do they behave under fault conditions?

The device includes hiccup-mode over-current protection (triggered at ~4.4A LS valley current), thermal shutdown at 175°C (with 20°C hysteresis), input over-voltage protection (37.5V trip), and undervoltage lockout. Under short-circuit, it cycles on/off with ~500ms period until fault clears - preventing damage while maintaining system visibility via PG deassertion.