Monolithic Power Systems Inc. MPQ2489DQ-LF-Z

Overview

MPQ2489DQ-LF-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified step-down white LED driver IC with 6V–55V input range, integrated 60V/1.41A MOSFET, 202mV ±30mV feedback reference voltage, and hysteretic control architecture enabling >95% efficiency and sub-100ns minimum on/off times. It drives high-brightness LEDs in automotive lighting systems requiring robust thermal protection and dual dimming.

For engineers reviewing the MPQ2489DQ-LF-Z datasheet, MPQ2489DQ-LF-Z pinout, MPQ2489DQ-LF-Z application, or MPQ2489DQ-LF-Z equivalent, key selection criteria include its wide-input capability, AEC-Q100 qualification, QFN6 package thermal resistance (θJA = 50°C/W), 1000:1 PWM dimming resolution, and open/short LED fault protection - all critical for automotive-grade LED lighting design.

Technical Context

The MPQ2489DQ-LF-Z implements a fixed-frequency hysteretic control loop that regulates LED current via high-side sensing across an external resistor, eliminating need for loop compensation while delivering fast transient response. Its internal 1.275V reference sets both enable threshold and current sense reference, with EN/DIM pin serving dual analog dimming (0.3V–2.5V) and PWM dimming (100Hz–2kHz) functions.

Thermal shutdown activates at 150°C junction temperature, and inherent open-LED and short-LED protection operate without external circuitry. The device sustains ≥1A continuous output current in QFN6 package under industrial/automotive temperature range (–40°C to +125°C TJ), with RDS(ON) = 0.5Ω and minimum switching time of 100ns per edge.

Key Specifications

Pinout & Package

MPQ2489DQ-LF-Z uses a thermally enhanced QFN6 (3mm × 3mm) package with exposed thermal pad, rated for 2.5W continuous power dissipation at TA = +25°C and θJC = 14°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT3965EFE#PBF and TLC59284PWR, the MPQ2489DQ-LF-Z offers a single-chip, AEC-Q100-qualified solution for high-current single-string automotive LED lighting - delivering superior thermal performance in QFN6, lower BOM count, and native 6V–55V operation without external FETs or pre-regulators.

Availability

MPQ2489DQ-LF-Z is available at Aetrix Electronics and suitable for automotive headlamps, commercial vehicle interior lighting, emergency exit signs, and industrial machine vision lighting requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MPQ2489DQ-LF-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 over 20 years of expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MPQ2489 belongs to MPS's automotive-grade LED driver product line, engineered specifically for AEC-Q100-compliant, high-reliability lighting in vehicles - emphasizing wide-input operation, integrated protection, and minimal external component count.

FAQ

What is the maximum LED string voltage supported by MPQ2489DQ-LF-Z?

The MPQ2489DQ-LF-Z does not regulate output voltage directly but maintains constant current through the LED string. Its maximum supported string voltage equals VIN minus the forward drop across the internal MOSFET and sense resistor - typically up to 52V at 55V input, assuming ≤3V total dropout. This supports up to 16 white LEDs (3.2V each) in series at full brightness.

Can MPQ2489DQ-LF-Z be used without a soft-start capacitor?

Yes - the MPQ2489DQ-LF-Z starts automatically when EN/DIM is left floating due to its internal 1.275V pull-up. However, omitting the recommended 1nF–10nF capacitor on EN/DIM may cause inrush current spikes and audible coil whine during startup. For production automotive designs, a 4.7nF capacitor is specified to achieve 0.3–0.5ms controlled soft-start.

How does the 202mV feedback reference improve efficiency compared to standard 1V references?

A 202mV reference reduces power dissipated in the current-sense resistor by ~96% versus a 1V reference (P = I²R). For a 550mA LED current, this cuts sense resistor loss from 550mW to 61mW - directly contributing to the >95% peak efficiency and enabling smaller, lower-cost 0.36Ω/1% resistors without thermal derating.

Is the EN/DIM pin compatible with 3.3V or 5V microcontroller GPIO outputs?

No - the EN/DIM pin must not exceed 2.56V (absolute max) and is designed for 0.3V–2.5V analog control or 1.5V–2.5V PWM signals. Direct connection to 3.3V/5V GPIO will damage the pin. Use a resistive divider or level-shifter; MPS recommends NPN transistor buffering for PWM signals, as shown in Figure 3 of the datasheet.

Does MPQ2489DQ-LF-Z require an output capacitor for stable operation?

No - the MPQ2489DQ-LF-Z operates stably without an output capacitor due to its hysteretic control architecture and current-mode regulation. An output capacitor (e.g., 2.2µF) is optional and only needed if peak-to-peak LED current ripple must be reduced below 30% of average current - typical in high-precision machine vision or flicker-sensitive applications.

What thermal pad soldering guidelines apply to the QFN6 package?

The QFN6 package requires a 3mm × 3mm thermal pad on the PCB with ≥80% solder paste coverage and 6–8 reflow solder joints connecting the pad to inner-layer copper planes. MPS specifies 1oz copper on Layer 2 and thermal vias (≥6 × 0.3mm) to internal ground planes to achieve θJA = 50°C/W - insufficient thermal relief causes premature thermal shutdown above 850mA at 85°C ambient.

How is open-LED protection implemented without external components?

Open-LED protection is inherent: when no current flows through RS, the feedback voltage collapses below 187mV (min spec), triggering the internal comparator to disable the MOSFET gate drive within 2µs. This halts switching and places the device in low-current shutdown mode - verified per AEC-Q100 stress testing with zero false trips across –40°C to +125°C.