Monolithic Power Systems Inc. MPQ4425BGQB-AEC1-P

Overview

MPQ4425BGQB-AEC1-P from Monolithic Power Systems is a synchronous step-down white LED driver IC with integrated 85mΩ/50mΩ MOSFETs, delivering up to 1.5A continuous LED current across 4V–36V input range, operating at 400kHz fixed frequency, and qualified to AEC-Q100 Grade 1 for automotive front/rear lighting systems.

For engineers reviewing the MPQ4425BGQB-AEC1-P datasheet, MPQ4425BGQB-AEC1-P pinout, MPQ4425BGQB-AEC1-P application, or MPQ4425BGQB-AEC1-P equivalent, this page provides verified functional context, validated QFN-13 (2.5mm×3mm) package mapping, confirmed PWM dimming support (100Hz–2kHz), fault signaling via open-drain /FAULT, and CISPR25 Class 5 EMI compliance data.

Technical Context

The MPQ4425BGQB-AEC1-P employs peak-current-mode control with internal 0.2V reference and error amplifier driving COMP voltage to regulate LED current. It integrates high-side and low-side power MOSFETs with valley-current detection for over-current protection and operates in forced continuous conduction mode (CCM) for stable frequency across load range.

Its bootstrap circuit uses an external capacitor between BST and SW pins to sustain high-side gate drive, with internal UVLO (2.2V rising, 150mV hysteresis) on the floating supply. Fault detection covers LED open, LED short-to-GND, short-to-LED−, and thermal shutdown (170°C trip, 140°C recovery), signaled via open-drain /FAULT.

Key Specifications

Pinout & Package

MPQ4425BGQB-AEC1-P is housed in a thermally enhanced QFN-13 package (2.5mm × 3.0mm, 0.5mm pitch) with exposed thermal pad. The package supports high-power density PCB layouts and requires solder paste stencil optimization for thermal pad void control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4425BGJ-AEC1, the MPQ4425BGQB-AEC1-P offers superior thermal dissipation for full 1.5A operation in automotive lighting, while LM3409QMYX/NOPB trades integration for flexibility in high-voltage or high-current designs - neither matches the combined AEC-Q100 Grade 1, CISPR25 Class 5, and integrated fault signaling of the QFN-13 variant.

Availability

MPQ4425BGQB-AEC1-P is available at Aetrix Electronics and suitable for automotive front headlamps, rear combination lamps, daytime running lights, and interior ambient lighting requiring stable component supply with AEC-Q100 qualification and long-term production continuity.

Supply support for MPQ4425BGQB-AEC1-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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ4425B product line delivers AEC-Q100-qualified LED drivers optimized for automotive exterior and interior lighting, emphasizing high efficiency, compact integration, and robust fault handling in harsh environments.

FAQ

What is the maximum allowable LED string voltage for MPQ4425BGQB-AEC1-P?

The device regulates LED current, not voltage; maximum LED string voltage depends on input voltage minus dropout. With 36V input and typical 1.2V switch-node overhead, up to ~34.8V LED string is supported - sufficient for 10× white LEDs (3.2V each) or 5× high-Vf red/amber LEDs (6.5V each). Output voltage is determined by V_IN – V_SW – I_LED×R_{DS(on)_LS}.

Can MPQ4425BGQB-AEC1-P operate in discontinuous conduction mode (DCM)?

No - it operates exclusively in forced continuous conduction mode (CCM) across all load conditions. This ensures fixed 400kHz switching frequency, predictable EMI behavior, and minimal output current ripple even at light loads, which is essential for flicker-free automotive lighting.

How is thermal performance affected by the QFN-13 exposed pad soldering?

Proper soldering of the exposed thermal pad to a dedicated PCB copper pour with ≥4 thermal vias (0.3mm diameter, filled or capped) reduces θ_JA from 60°C/W (JESD51-7) to ~42°C/W (MPS EVB), enabling full 1.5A operation at +85°C ambient. Insufficient pad connection causes thermal shutdown at ≤1.0A.

What external components are mandatory for basic operation?

Four components are mandatory: (1) Input capacitor (≥10μF ceramic, X5R/X7R), (2) Output inductor (6.8–10μH, 2.5A saturation current), (3) Bootstrap capacitor (0.1μF ceramic), and (4) Current-sense resistor (value sets I_LED = 0.2V/R_SENSE). VCC decoupling (0.1–0.22μF) is also required.

Does the /FAULT pin require a pull-up resistor, and what value is recommended?

Yes - /FAULT is open-drain and must be pulled up to a logic-compatible voltage (e.g., VCC or 3.3V). A 100kΩ resistor is recommended: it ensures sufficient sink current (>100μA) for reliable low-state detection while minimizing standby current (<0.1μA) during normal operation.

Is PWM dimming compatible with analog dimming via the FB pin?

No - the MPQ4425BGQB-AEC1-P supports only PWM dimming via the EN/DIM pin. Analog dimming by injecting current into FB is not supported; doing so disrupts the internal error amplifier's reference tracking and may cause instability or inaccurate current regulation.

What is the minimum recommended PCB trace width for the IN and SW pins?

For 1.5A continuous operation, IN and SW traces should be ≥15 mils (0.38mm) wide with 2oz copper and adjacent ground pour. For high-reliability automotive use, ≥20 mils (0.5mm) is recommended to limit temperature rise to <10°C and reduce EMI radiation from high di/dt switching nodes.