Monolithic Power Systems Inc. MPQ4425MGQB-AEC1-P

Overview

MPQ4425MGQB-AEC1-P from Monolithic Power Systems is a synchronous step-down LED driver IC designed for automotive front/rear lighting systems, delivering 1.5A continuous output current with 4V–36V input range, 2.2MHz fixed switching frequency, and AEC-Q100 Grade-1 qualification.

For engineers reviewing the MPQ4425MGQB-AEC1-P datasheet, MPQ4425MGQB-AEC1-P pinout, MPQ4425MGQB-AEC1-P application, or MPQ4425MGQB-AEC1-P equivalent, key selection criteria include its integrated 85mΩ/50mΩ MOSFETs, 0.2V feedback reference, PWM dimming support (100Hz–2kHz), fault-indicating open-drain /FAULT pin, and CISPR25 Class 5 EMI compliance for automotive environments.

Technical Context

The MPQ4425MGQB-AEC1-P operates in fixed-frequency peak-current-mode control with forced continuous conduction mode (CCM) across full load range, enabling stable regulation and low output ripple. Its internal error amplifier compares FB voltage to a 0.2V reference and drives a compensation network to generate VCOMP, which controls high-side MOSFET on-time.

It integrates dual power MOSFETs (HS R_DS(ON) = 85mΩ, LS R_DS(ON) = 50mΩ), a 4.9V internal VCC regulator, valley-current-detect OCP, thermal shutdown at 170°C (30°C hysteresis), and bootstrap circuitry with 20Ω recommended BST resistor for SW spike suppression.

Key Specifications

Pinout & Package

MPQ4425MGQB-AEC1-P is housed in a wettable-flank QFN-13 package (2.5mm × 3mm, 0.5mm pitch), optimized for automated optical inspection (AOI) and thermal performance in automotive PCB assemblies.

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 TPS92630QPWPRQ1, MPQ4425MGQB-AEC1-P delivers higher integration (dual MOSFETs, 0.2V reference, fault reporting), automotive-grade qualification out-of-box, and smaller total solution size - making it optimal for cost-sensitive, space-constrained 1.5A automotive LED applications.

Availability

MPQ4425MGQB-AEC1-P is available at Aetrix Electronics and suitable for automotive daytime running lights, rear combination lamps, front fog lamps, and license plate illumination requiring stable component supply with AEC-Q100 assurance and long-term production continuity.

Supply support for MPQ4425MGQB-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 analog and power ICs, with core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MPQ4425M product line targets automotive LED lighting applications demanding high efficiency, small form factor, and AEC-Q100 reliability - specifically engineered for headlamp, DRL, and fog lamp subsystems operating across wide input voltage ranges.

FAQ

What is the minimum recommended input capacitance for MPQ4425MGQB-AEC1-P?

The datasheet specifies a minimum 4.7µF X5R/X7R ceramic capacitor at the IN pin, plus an additional 0.1µF 0603 ceramic placed directly between IN and PGND. This dual-capacitor approach handles both bulk energy storage and high-frequency switching noise, ensuring stable operation under load-dump conditions and minimizing input voltage ripple below 50mV.

Can MPQ4425MGQB-AEC1-P drive more than two series-connected LEDs?

Yes - the device supports LED string voltages up to VIN − 2V (e.g., 34V at 36V input). With a 1.5A output and typical white LED forward voltage of 3.2V, it can drive up to 10 LEDs in series (32V) at room temperature. Thermal derating applies above 85°C ambient; maximum string voltage must stay within the 36V absolute maximum input rating minus safety margin.

How does the /FAULT pin behave during thermal shutdown?

During thermal shutdown, the /FAULT pin is actively pulled low by an internal NMOS transistor, providing unambiguous fault signaling. It remains low until die temperature drops below 140°C (30°C hysteresis), at which point the IC resumes normal operation and /FAULT returns high via external pull-up. No external debouncing is required due to built-in 10µs delay.

Is an external bootstrap diode necessary for reliable operation?

No - the internal bootstrap circuit functions reliably across all duty cycles. However, an external Schottky diode (e.g., IN4148) is recommended when duty cycle exceeds 65% to improve high-VIN efficiency by reducing BST capacitor charging losses. The diode connects from VOUT (or VCC) to BST, bypassing the internal charge path during high-side conduction.

What is the impact of using a 100kΩ pull-up on the /FAULT pin?

A 100kΩ pull-up ensures adequate noise immunity while limiting fault-reporting current to <50µA at 5V - well within the /FAULT sink capability (4mA @ 0.4V). This value balances fast rise time (<100ns) with minimal power draw, supporting direct interfacing to 3.3V or 5V microcontrollers without level-shifting.

Does MPQ4425MGQB-AEC1-P support analog dimming via the EN/DIM pin?

No - the EN/DIM pin only supports digital PWM dimming (100Hz–2kHz). Analog dimming is not implemented; attempting variable DC voltage on EN/DIM will only enable/disable the device. For analog control, an external current-sense amplifier with DAC-controlled reference is required - but defeats the purpose of the integrated 0.2V reference architecture.

How is UVLO threshold adjusted using external resistors?

UVLO can be raised by connecting a resistor divider between IN and EN/DIM pins. With R_DOWN = 500kΩ fixed, R_UP is calculated using V_{EN_RISING} = 1.45V and target V_{IN_UVLO}; e.g., for 12V UVLO, R_UP ≈ 3.7MΩ. R_UP must limit EN current to <100µA - verified by (V_IN − 6.5V)/R_UP ≤ 100µA per datasheet guidance.