Monolithic Power Systems Inc. MPQ7231GLE-D50-AEC1-Z

Overview

MPQ7231GLE-D50-AEC1-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified, synchronous infrared LED driver configurable as a buck (3A peak) or buck-boost (2.4A peak) converter with factory-trimmed 5ms dimming on-time limit, integrated 44mΩ/40mΩ MOSFETs, and 6V–42V input range-designed for automotive driver monitoring systems (DMS) requiring eye-safe IR illumination.

For engineers reviewing the MPQ7231GLE-D50-AEC1-Z datasheet, MPQ7231GLE-D50-AEC1-Z pinout, MPQ7231GLE-D50-AEC1-Z application, or MPQ7231GLE-D50-AEC1-Z equivalent, this device delivers deterministic PWM dimming (10Hz–2kHz), ultra-fast hysteretic control, ASIL-aligned eye-safety features, and QFN-19 wettable flank packaging for automotive-grade thermal and EMC robustness.

Technical Context

The MPQ7231 operates in constant-frequency hysteretic control mode-eliminating loop compensation while enabling sub-100ns transient response to LED current steps. Its dual-mode topology selection (buck vs. buck-boost) is determined by external resistor value at IREF (≥14.7kΩ or ≤9.09kΩ), directly configuring switching frequency (2.4MHz or 1.25MHz) and FSS modulation bandwidth.

Eye safety is enforced via three factory-trimmed dimming on-time limits (1ms/3ms/5ms); the -D50 variant fixes this at 5ms. Thermal derating uses NTC-based remote sensing with programmable current scaling (5× or 50× IREF), and fault detection includes open/short LED, over-current latch, and thermal shutdown at 155°C–185°C.

Key Specifications

Pinout & Package

MPQ7231GLE-D50-AEC1-Z is housed in a thermally enhanced QFN-19 (3mm × 4mm) package with wettable flanks and exposed thermal pad (PGND-connected). Pin 1 is marked by a dot; pins are numbered counter-clockwise from top-left corner in top view.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar infrared LED driver applications.

Compared with MPQ7231GLE-D30-AEC1-Z and MPQ7231GLE-D10-AEC1-Z, the MPQ7231GLE-D50-AEC1-Z provides the longest factory-set dimming on-time-maximizing usable photon flux per frame while retaining ASIL-B alignment, making it optimal for DMS systems prioritizing image SNR over minimal exposure duration.

Availability

MPQ7231GLE-D50-AEC1-Z is available at Aetrix Electronics and suitable for automotive driver monitoring systems (DMS), IR illumination for automotive cameras, and surveillance systems requiring stable component supply, AEC-Q100 qualification, and long-term production continuity.

Supply support for MPQ7231GLE-D50-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 power management ICs, with core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MPQ7231 belongs to MPS's MPSafe™ automotive-grade LED driver product line-engineered specifically for functional safety-critical infrared illumination in driver monitoring, ADAS, and in-cabin sensing applications.

FAQ

What is the purpose of the IREF pin, and how does it affect topology selection?

The IREF pin sets both the operating topology (buck or buck-boost) and NTC current scaling factor. A resistor ≥14.7kΩ selects buck mode (2.4MHz, 3A peak) with 50× IREF NTC current; ≤9.09kΩ selects buck-boost (1.25MHz, 2.4A peak) with 5× IREF current. Open or short faults on IREF cause latch-off and FAULT assertion.

How does the 5ms dimming on-time limit function, and is it adjustable?

The 5ms limit is factory-trimmed and non-adjustable-it is hard-coded into the MPQ7231GLE-D50-AEC1-Z die. The DIM pin accepts external PWM, but internal circuitry clamps active high duration to exactly 5ms (typical 4–6ms range per datasheet), ensuring repeatable eye safety compliance without software or external components.

Can the MPQ7231 operate in buck-boost mode with input voltage below the LED forward voltage?

Yes. In buck-boost mode, the device regulates LED current even when VIN is lower than total V_f (e.g., 6.6V input driving three 3V IR LEDs = 9V total). The topology inherently supports step-up functionality, with peak current capability of 2.4A and continuous current up to 1.2A at nominal conditions.

What thermal derating behavior occurs when the NTC voltage drops below 0.53V?

When V_NTC falls to 0.53V (corresponding to 50% of nominal LED current setting), the device initiates thermal derating-reducing I_LED proportionally to maintain safe junction temperature. Derating continues down to zero current at V_NTC = 0.37V, which triggers full thermal shutdown.

Does the FAULT pin indicate all fault conditions simultaneously, or can individual faults be distinguished?

The FAULT pin is a single-wire open-drain indicator that asserts low for any detected fault-LED open/short, over-current, thermal shutdown, or false mode-but does not encode fault type. External logic or MCU polling of status flags (if implemented) is required for root-cause identification; no internal register interface exists.

How does frequency spread spectrum (FSS) improve EMC performance in automotive environments?

FSS modulates the switching frequency by ±10% around the nominal value (2.4MHz or 1.25MHz), spreading energy across a wider bandwidth and reducing peak amplitudes in conducted/radiated EMI spectra. This enables compliance with stringent CISPR25 Class 5 limits without adding bulky EMI filters or shielding.

Is the QFN-19 package with wettable flanks compatible with standard automotive SMT reflow profiles?

Yes. The QFN-19 (3mm × 4mm) with wettable flanks is qualified for J-STD-020 moisture sensitivity level 1 and supports standard lead-free reflow profiles (peak 260°C). Wettable flanks enable reliable AOI inspection of solder joints-critical for automotive process validation and field reliability.