Monolithic Power Systems Inc. MPQ4420HGJ-P

Overview

MPQ4420HGJ-P from Monolithic Power Systems is a high-efficiency, AEC-Q100 Grade 1 qualified synchronous step-down DC/DC converter delivering up to 2A continuous output current. It operates from 4V to 36V input, regulates output down to 0.8V with ±1.5% feedback reference accuracy, and integrates 90mΩ/55mΩ MOSFETs in an 8-pin TSOT23 package-designed for automotive power rails including cold-crank conditions.

For engineers reviewing the MPQ4420HGJ-P datasheet, MPQ4420HGJ-P pinout, MPQ4420HGJ-P application, or MPQ4420HGJ-P equivalent, key selection criteria include its 410kHz default switching frequency, EN/SYNC dual-function pin, Power Good open-drain output, thermal shutdown at 170°C, and support for external clock synchronization from 200kHz to 2.2MHz.

Technical Context

The MPQ4420HGJ-P uses peak-current-mode control with internal compensation, enabling stable regulation across wide load and line variations without external loop components. Its integrated high-side and low-side MOSFETs operate in synchronous rectification mode, eliminating external diode losses and improving light-load efficiency via Power-Save Mode.

It features a dedicated bootstrap driver with internal 5V regulator for high-side gate drive, programmable UVLO thresholds (3.5V rising / 3.3V falling), and hiccup-mode over-current protection triggered when FB falls below 84% of reference-critical for automotive short-circuit resilience.

Key Specifications

Pinout & Package

MPQ4420HGJ-P is housed in an 8-pin TSOT23 package (3.0mm × 3.0mm × 0.9mm), optimized for space-constrained automotive and industrial PCB layouts. The exposed pad is not electrically connected and serves only thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM61480RQWR and TPS54240DGQR, MPQ4420HGJ-P uniquely combines AEC-Q100 Grade 1 qualification, integrated 2A MOSFETs in TSOT23-8, Power Good signaling, and cold-crank-ready 95% duty cycle-making it optimal for space- and reliability-critical automotive body electronics.

Availability

MPQ4420HGJ-P is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC I/O power supplies, distributed ADAS camera systems, and ruggedized telematics units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MPQ4420HGJ-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 analog and power ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ4420H product line delivers compact, AEC-Q100-qualified DC/DC converters targeting automotive infotainment, ADAS, and body electronics where high input voltage range, thermal robustness, and small footprint are critical.

FAQ

What is the maximum allowable input voltage for MPQ4420HGJ-P, and what happens beyond that?

The absolute maximum input voltage is 40V. Exceeding this risks permanent damage to the internal MOSFETs and control circuitry. The device includes built-in over-voltage protection on the IN pin only through external clamping-no internal crowbar or foldback above 40V. Operation above 36V is outside recommended conditions and degrades reliability, especially at high ambient temperatures.

Can MPQ4420HGJ-P operate with an input voltage below 4V, and what is the minimum functional VIN?

No-it will not regulate below 4V due to internal UVLO (rising threshold 3.5V). Below 4V, the device remains in shutdown regardless of EN state. For cold-crank scenarios where battery dips to 4.2V, the 95% max duty cycle ensures regulation down to VOUT = 0.9 × VIN, enabling 3.3V output from 3.67V input-meeting automotive ISO 16750-2 pulse 4 requirement.

How does the EN/SYNC pin function in both enable and synchronization modes?

When held above 1.4V (typical), EN/SYNC enables the converter. When driven with a 200kHz–2.2MHz square wave after startup (≥2ms post-VOUT regulation), it overrides the internal oscillator and locks phase to the external clock edge. The pin has internal 500kΩ pull-down and 6.5V Zener clamp-direct connection to >6V sources requires current limiting per datasheet Figure 2.

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

The 20Ω resistor between BST and SW damps ringing and reduces voltage spikes on the switch node during high dv/dt transitions. This protects the bootstrap capacitor dielectric and improves EMI performance. Higher resistance further suppresses spikes but increases power loss in the bootstrap path-20Ω balances spike suppression, efficiency, and reliability across temperature and load conditions.

Does MPQ4420HGJ-P support adjustable soft-start time, and how is it controlled?

No-the soft-start period is fixed at 1.5ms (typical) and internally generated. The SS voltage ramps from 0V to 1.2V, overriding the 0.792V reference until regulation is established. No external capacitor or resistor adjusts this timing. This simplifies design but means startup behavior is invariant across applications.

What thermal derating applies to the 2A output current rating in the TSOT23-8 package?

At TA = +25°C, full 2A is achievable with θJA = 100°C/W. At +85°C ambient, maximum continuous current drops to ~1.5A assuming no PCB copper area enhancement. Derating follows PD = (TJmax − TA)/θJA; with TJmax = 125°C (recommended max operating), 1.25W max dissipation limits current based on efficiency-e.g., at 85% efficiency and 12V→3.3V, 1.25W corresponds to ~1.7A.

Is the PG pin actively driven high, or is it open-drain only?

PG is strictly open-drain: an NMOS transistor pulls low when VFB < 90% × VFB or during fault conditions (thermal shutdown, EN low). It floats high otherwise and requires an external pull-up resistor (typically 10kΩ–100kΩ) to VCC or another bias rail. No internal pull-up exists-leaving PG unconnected results in undefined logic level.