Monolithic Power Systems Inc. MP4423HGQ-Z

Overview

MP4423HGQ-Z from Monolithic Power Systems is a high-frequency, synchronous step-down DC/DC converter with integrated 85mΩ/55mΩ MOSFETs, delivering up to 3A continuous output current across a 4V–36V input range. It features fixed 410kHz switching, internal soft-start, power-good signaling, and thermal shutdown-designed for automotive cold-crank and industrial distributed power systems.

For engineers reviewing the MP4423HGQ-Z datasheet, MP4423HGQ-Z pinout, MP4423HGQ-Z application, or MP4423HGQ-Z equivalent, key selection criteria include its wide VIN range, synchronous efficiency, EN/SYNC dual-function pin, PG open-drain output, and QFN-8 (3mm×3mm) thermal performance in space-constrained designs.

Technical Context

The MP4423HGQ-Z employs peak-current-mode control with an internal 0.8V reference and optimized compensation, enabling stable regulation without external loop components. Its current-mode architecture delivers fast transient response and inherent cycle-by-cycle overcurrent protection.

It integrates a bootstrap charging circuit with dedicated UVLO (2.2V rising), supports external clock synchronization from 200kHz to 2.2MHz, and implements hiccup-mode fault recovery during sustained short-circuit conditions-ensuring robust operation in automotive and industrial environments.

Key Specifications

Pinout & Package

MP4423HGQ-Z is housed in a thermally enhanced QFN-8 (3mm × 3mm) package with exposed thermal pad, supporting ≤2.27W continuous power dissipation at +25°C ambient (θ_JA = 55°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4423HGQ-Z, the MP4423HGQ-Z trades automotive qualification for lower cost and faster availability, while LM61480RGER offers higher max frequency but demands more layout effort for BST and cold-crank resilience-making MP4423HGQ-Z optimal for cost-sensitive industrial and medical designs requiring guaranteed 4V operation.

Availability

MP4423HGQ-Z is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, and distributed telecom equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP4423HGQ-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 analog and power ICs, with core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP4423H product line targets high-reliability, wide-input industrial and automotive power conversion-designed to replace discrete buck solutions with integrated MOSFETs, protection, and thermal optimization in minimal footprint.

FAQ

What is the minimum input voltage required for MP4423HGQ-Z to start switching?

The MP4423HGQ-Z has a guaranteed 4V minimum operating input voltage and initiates switching when VIN exceeds the UVLO rising threshold of 3.5V. It sustains regulation down to 4V even at full 3A load, making it suitable for automotive cold-crank events where battery voltage dips below 6V.

Can MP4423HGQ-Z be synchronized to an external clock, and what is the valid frequency range?

Yes-the EN/SYNC pin accepts an external clock signal from 200kHz to 2.2MHz. The device synchronizes its internal oscillator to the rising edge of the external clock within 2ms of output regulation, enabling EMI reduction and multi-rail phase alignment in complex power systems.

How does the power-good (PG) pin behave during startup and fault conditions?

The PG pin is an open-drain output that remains low until VOUT reaches 90% of the target (e.g., 2.97V for 3.3V output), then asserts high after a 40–160μs delay. It pulls low again if VOUT drops below 84% of target, or immediately upon EN deactivation, thermal shutdown, or overcurrent hiccup entry.

What is the purpose of the BST pin, and why is a 20Ω resistor recommended?

The BST pin supplies gate drive voltage to the high-side MOSFET via a bootstrap capacitor between BST and SW. A 20Ω resistor in series limits inrush current into the BST capacitor, reducing SW node voltage spikes and EMI-especially critical at high duty cycles and fast switching edges.

Does MP4423HGQ-Z require external compensation components for stability?

No-MP4423HGQ-Z features an internally compensated current-mode controller optimized for standard output capacitor types (ceramic, tantalum, electrolytic). Stability is maintained across 10μF–1000μF output capacitance with ESR from 1mΩ to 100mΩ, eliminating the need for external compensation networks.

What thermal derating applies to the QFN-8 package at elevated ambient temperatures?

With θ_JA = 55°C/W on a 4-layer PCB, the MP4423HGQ-Z delivers full 3A output up to +85°C ambient. Above that, output current must be linearly reduced: at +100°C ambient, max continuous current is ~2.2A; at +125°C, it drops to ~1.4A-per the thermal shutdown activation at 170°C junction temperature.

Is there a recommended layout practice for minimizing EMI in MP4423HGQ-Z designs?

Yes-place the 22μF input capacitor and 1μF high-frequency bypass capacitor as close as possible to IN and GND pins with short, wide traces; use a solid ground plane beneath the IC; route SW and BST away from FB and analog traces; and connect the thermal pad to ground with ≥4 thermal vias to maximize heat dissipation and reduce radiated emissions.