Monolithic Power Systems Inc. MP4323GDE-Z

Overview

MP4323GDE-Z from Monolithic Power Systems is a 42V load-dump-tolerant, 3A synchronous step-down converter with integrated 70mΩ high-side and 50mΩ low-side MOSFETs, 3.3V–36V input range, 1μA shutdown current, and configurable 350kHz–2.5MHz switching frequency - designed for automotive USB chargers and battery-powered systems operating down to 3.1V cold-crank.

For engineers reviewing the MP4323GDE-Z datasheet, MP4323GDE-Z pinout, MP4323GDE-Z application, or MP4323GDE-Z equivalent, key selection criteria include load-dump immunity, ultra-low IQ in sleep mode (20μA), CISPR25 Class 5 EMI compliance, thermal performance up to +125°C junction temperature, and QFN-12 (2mm×3mm) wettable flank package for automated optical inspection.

Technical Context

The MP4323GDE-Z employs peak current-mode control with frequency foldback during start-up to prevent inductor current runaway. Its integrated power stage supports high duty cycle and low-dropout mode for automotive cold-crank conditions (VIN ≥ 3.1V), while asymmetric minimum on/off times (65ns/50ns) enable stable operation at high VIN/VOUT ratios.

EMI mitigation is achieved via frequency spread spectrum (±10% modulation), symmetric VIN pins (Pin 2 & Pin 10), and MeshConnect™ flip-chip packaging. The open-drain PG output monitors VOUT within ±5.5% of nominal, with 70µs rising and 60µs falling deglitch timing to reject transient noise.

Key Specifications

Pinout & Package

The MP4323GDE-Z is housed in a QFN-12 (2mm × 3mm) wettable flank package with exposed thermal pad, optimized for high-density automotive PCB layouts and automated optical solder-joint inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480QRTWRQ1 and TPS62933RTER, the MP4323GDE-Z uniquely combines wettable flank packaging for AOI, CISPR25 Class 5 compliance without filtering, and guaranteed 3.1V cold-crank operation - making it the only option qualified for direct engine-bay placement in modern ADAS platforms.

Availability

MP4323GDE-Z is available at Aetrix Electronics and suitable for automotive USB charging, ADAS camera power, telematics control units, and infotainment system core supplies requiring stable component supply across extended temperature and high-reliability environments.

Supply support for MP4323GDE-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 markets, with design centers in the US, China, and Taiwan.

The MP4323 belongs to MPS's automotive-qualified DC-DC converter product line, engineered specifically for harsh-environment applications demanding load-dump tolerance, ultra-low IQ, and certified EMI performance - targeting next-generation ADAS, body electronics, and electrified powertrain subsystems.

FAQ

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

The MP4323GDE-Z has a VIN UVLO rising threshold of 3.65V (typical), requiring ≥3.8V to initiate startup. Once running, it sustains regulation down to 3.1V - meeting automotive cold-crank specifications per ISO16750-2. This dual-threshold behavior ensures reliable ignition sequence handling without brownout resets.

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

FSS modulates switching frequency by ±10% at 15kHz, spreading energy across a bandwidth instead of concentrating at harmonics. This reduces peak conducted/radiated emissions by up to 10dB, enabling pass-fail compliance with CISPR25 Class 5 without added ferrite beads or shielding - verified on standard 4-layer EVQ4323-D-00A evaluation board.

Can the MP4323GDE-Z operate without an external feedback resistor divider?

Yes - the MP4323GDE-Z supports both adjustable and fixed-output configurations. For fixed output, connect FB directly to VOUT; the internal reference remains 0.8V, so fixed versions require factory-trimmed internal resistors (e.g., MP4323HGDE-Z for 5V). The GDE-Z variant is adjustable and requires external RFB1/RFB2.

What thermal derating applies at +105°C ambient temperature?

Using θJA = 35.5°C/W (EVQ4323-D-00A board), maximum continuous output current drops to ~2.4A at TA = +105°C to maintain TJ ≤ +125°C. Derating is linear: 3A at 25°C ambient, 2.7A at 50°C, 2.4A at 105°C. Thermal shutdown activates at 160°C with 20°C hysteresis.

Is the PG signal compatible with 1.8V logic microcontrollers?

Yes - the open-drain PG output sinks ≥1mA at 0.3V (max), allowing direct interface with 1.8V, 3.3V, or 5V logic. Use a pull-up resistor to the controller's I/O supply rail (e.g., 10kΩ to 1.8V). PG asserts high when VOUT is within 94.5–105.5% of target, with 70µs deglitch to suppress switching noise.

Does the QFN-12 wettable flank package support automated optical inspection (AOI)?

Yes - the wettable flank design exposes vertical copper sidewalls on all perimeter pins, enabling high-accuracy solder-joint inspection using standard AOI systems. This eliminates manual visual checks and improves first-pass yield in automotive SMT lines, especially critical for safety-critical ADAS assemblies.

How is over-current protection implemented during short-circuit events?

OCP uses valley-current limiting on the low-side FET and peak-current limiting on the high-side FET, triggering hiccup mode: the device shuts down for 3ms, then attempts soft-start recovery. ILIMIT_LS is 4.4A (typ) and ILIMIT_HS is 5.8A (typ), providing robust fault containment without latch-up or external circuitry.