Monolithic Power Systems Inc. MPQ4425MGQBE-AEC1-Z

Overview

MPQ4425MGQBE-AEC1-Z from Monolithic Power Systems is a synchronous step-down white LED driver IC with integrated 85mΩ/50mΩ MOSFETs, delivering 1.5A continuous output current across 4V–36V input range, operating at 2.2MHz fixed frequency, and qualified to AEC-Q100 Grade-1 for automotive lighting systems.

For engineers reviewing the MPQ4425MGQBE-AEC1-Z datasheet, MPQ4425MGQBE-AEC1-Z pinout, MPQ4425MGQBE-AEC1-Z application, or MPQ4425MGQBE-AEC1-Z equivalent, key selection criteria include its wettable-flank QFN-13 package, PWM dimming support (100Hz–2kHz), fault-indicating open-drain /FAULT pin, and CISPR25 Class 5 EMI compliance for automotive front/rear lighting designs.

Technical Context

The MPQ4425MGQBE-AEC1-Z uses peak-current-mode control with internal 0.2V reference and valley-current detection for over-current protection. It operates in forced continuous conduction mode (CCM) across full load range, ensuring stable 2.2MHz switching up to 1.5A output.

Its bootstrap circuit supports high-side gate drive with internal UVLO (2.2V rising), and thermal shutdown activates at 170°C with 30°C hysteresis. Fault reporting via /FAULT pin covers LED short, open, and thermal events with 10μs response delay.

Key Specifications

Pinout & Package

MPQ4425MGQBE-AEC1-Z is housed in a wettable-flank QFN-13 package (2.5mm × 3mm, 0.5mm pitch), optimized for automated optical inspection (AOI) and solder joint reliability in automotive PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4425MGQBE-AEC1-Z, MPQ4425MGQB-AEC1-Z offers identical performance but lacks wettable flanks for AOI, while LM3409QMYX/NOPB trades integration for design adaptability - making the MPQ4425MGQBE-AEC1-Z optimal for space-constrained, high-reliability automotive LED modules.

Availability

MPQ4425MGQBE-AEC1-Z is available at Aetrix Electronics and suitable for automotive front lighting, rear lighting, daytime running lights, and interior ambient lighting requiring stable component supply with AEC-Q100 compliance and long-term production support.

Supply support for MPQ4425MGQBE-AEC1-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, LED drivers, and motor control solutions.

The MPQ4425M product line delivers highly integrated, AEC-Q100-qualified LED drivers targeting automotive exterior lighting applications where efficiency, EMI performance, and thermal robustness are critical.

FAQ

What is the purpose of the /FAULT pin, and how should it be interfaced?

The /FAULT pin is an open-drain output that pulls low during LED short, LED open, or thermal shutdown events. It must be externally pulled up to VCC (or another logic-compatible voltage) using a resistor (typically 100kΩ). Its 10μs response time enables rapid system-level fault detection, and it remains high during normal operation - providing simple status monitoring without additional circuitry.

Can MPQ4425MGQBE-AEC1-Z operate below 4V input?

No - the absolute minimum operating input voltage is 4V per datasheet specifications. Below this threshold, the internal UVLO circuit disables operation to prevent unstable regulation. The rising UVLO threshold is 3.5V (±0.3V), and falling threshold is 3.1V, with 400mV hysteresis. Operation below 4V risks undefined behavior and is outside AEC-Q100 qualification limits.

How does the BST pin function, and why is a 20Ω resistor recommended?

The BST pin supplies gate drive voltage to the internal high-side MOSFET via a bootstrap capacitor connected between BST and SW. A 20Ω resistor in series with the BST capacitor dampens ringing and reduces SW node voltage spikes during switching transitions - improving EMI performance and gate drive stability without significantly impacting efficiency.

Is PWM dimming supported, and what are the timing constraints?

Yes - PWM dimming is implemented via the EN/DIM pin, accepting external signals from 100Hz to 2kHz. Minimum amplitude is 1.8V. If applied before soft-start completion, the high pulse must exceed 2ms to ensure stable current ramp-up; no such constraint applies after startup. Dimming duty cycle directly controls average LED current.

What distinguishes the "E" suffix in MPQ4425MGQBE-AEC1-Z?

"E" denotes the wettable flank variant of the QFN-13 package - featuring solderable side walls that enable automated optical inspection (AOI) of solder joints. This is critical for automotive Tier-1 suppliers requiring zero-defect assembly verification, unlike the standard MPQ4425MGQB-AEC1-Z which lacks this feature despite identical electrical performance.

Does the device support adjustable UVLO, and how is it implemented?

Yes - although internal UVLO thresholds are fixed (3.5V rising / 3.1V falling), an external resistor divider between IN and EN/DIM can raise the effective enable threshold. Using equations from the datasheet (R_UP and R_DOWN), designers can set custom rising/falling points while ensuring EN input current stays below 100μA to avoid overstressing the internal Zener clamp.

What is the maximum achievable LED string voltage with this driver?

The MPQ4425MGQBE-AEC1-Z regulates current, not voltage - so maximum string voltage depends on input headroom and inductor saturation. With 36V max input and typical 0.4V dropout across internal FETs and sense resistor, practical string voltage is ≤35.6V. For two 3V white LEDs (6V total), it supports up to five strings in parallel at 1.5A each, provided thermal design accommodates total power dissipation.