Monolithic Power Systems Inc. MPQ4425MGQB-P

Overview

MPQ4425MGQB-P from Monolithic Power Systems is a synchronous step-down LED driver IC with integrated 85mΩ/50mΩ MOSFETs, delivering 1.5A continuous output current across a 4V–36V input range, operating at a fixed 2.2MHz switching frequency, and qualified to AEC-Q100 Grade-1 for automotive front/rear lighting systems.

For engineers reviewing the MPQ4425MGQB-P datasheet, MPQ4425MGQB-P pinout, MPQ4425MGQB-P application, or MPQ4425MGQB-P equivalent, key selection criteria include its forced CCM mode, 0.2V feedback reference, PWM dimming support (100Hz–2kHz), fault indication (/FAULT open-drain), and CISPR25 Class 5 EMI compliance in QFN-13 wettable flank packaging.

Technical Context

The MPQ4425MGQB-P employs peak-current-mode control with internal 0.2V reference and error amplifier driving COMP voltage to regulate LED current via valley-current detection OCP. Its fixed-frequency architecture supports forced CCM operation across full load range, eliminating audible noise and enabling predictable EMI filtering.

Bootstrap gate drive enables high-side MOSFET operation with internal UVLO (2.2V rising) on BST; thermal shutdown activates at 170°C with 30°C hysteresis; /FAULT pin signals LED short/open or TSD via open-drain output requiring external pull-up.

Key Specifications

Pinout & Package

MPQ4425MGQB-P is housed in a space-saving QFN-13 package (2.5mm × 3mm) with wettable flanks for automated optical inspection (AOI) and enhanced solder joint reliability in automotive reflow processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3409QMYX/NOPB and TPS92692QPWPRQ1, MPQ4425MGQB-P delivers optimal integration density and automotive qualification at 1.5A/36V, trading off maximum input voltage and spread-spectrum capability for smaller footprint, lower component count, and direct fault signaling - making it ideal for space-constrained front/rear lighting modules.

Availability

MPQ4425MGQB-P is available at Aetrix Electronics and suitable for automotive LED lighting, daytime running lights (DRL), adaptive front lighting systems (AFS), and interior ambient lighting requiring stable component supply, AEC-Q100 compliance, and production-ready EMI performance.

Supply support for MPQ4425MGQB-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 MPQ4425M product line targets automotive-grade LED drivers, emphasizing AEC-Q100 qualification, CISPR25 compliance, and integration of power switches, protection, and dimming interfaces to simplify lighting module design.

FAQ

What is the recommended input capacitor configuration for MPQ4425MGQB-P?

Use a parallel combination: a 4.7µF–10µF X5R/X7R ceramic capacitor for bulk energy storage and a 0.1µF 0603 ceramic capacitor placed directly between IN and PGND pins. The small capacitor must be located within 2mm of the IC to suppress high-frequency switching noise; total RMS current rating should exceed 0.75A based on worst-case 1.5A load.

How does the /FAULT pin indicate specific fault conditions?

The /FAULT pin is an open-drain output pulled low for ≥10µs during LED short, LED open, or thermal shutdown events. It does not distinguish between fault types - external MCU must correlate /FAULT assertion with EN/DIM state, temperature monitoring, and LED voltage sensing to identify root cause. No internal debouncing is applied.

Can MPQ4425MGQB-P operate below 4V input?

No - the absolute minimum operating input voltage is 4V per datasheet specifications. Below this, the internal bias regulator cannot sustain VCC at 4.9V, causing undefined behavior and potential failure to start. The UVLO rising threshold is 3.5V, but functional operation requires ≥4V to ensure stable gate drive and regulation.

What is the purpose of the 20Ω resistor between SW and BST pins?

The 20Ω resistor dampens ringing on the bootstrap node during high dv/dt transitions, reducing SW voltage spikes that could trigger false overvoltage protection or degrade BST capacitor lifetime. It trades ~0.3% efficiency loss for improved reliability - omitting it risks premature BST capacitor failure under high-temperature, high-duty-cycle conditions.

Is external compensation required for stable loop operation?

No - MPQ4425MGQB-P features an optimized internal compensation network designed for typical 2.2µH inductors and 133mΩ R_FB. External RT resistor (100kΩ recommended) may be added to adjust loop bandwidth if using non-standard inductance or output capacitance, but is not required for baseline operation with datasheet-recommended components.

Does MPQ4425MGQB-P support analog dimming?

No - the device only supports PWM dimming via the EN/DIM pin. Analog dimming (current adjustment via FB voltage scaling) is not implemented; the 0.2V reference is fixed and unmodulated. Attempting analog control by injecting current into FB will disrupt regulation and may trigger OCP due to erroneous error amplifier output.

What is the thermal resistance (θ_JA) of the QFN-13 package under standard JEDEC conditions?

The specified θ_JA is 60°C/W when measured on a 4-layer JEDEC JESD51-7 test board with 2oz copper, 1in² exposed pad area, and 10 thermal vias. In actual automotive PCB layouts with enhanced thermal pads and multiple inner-layer ground planes, measured θ_JA typically improves to 42–48°C/W, enabling 1.5A operation at +105°C ambient without derating.