Monolithic Power Systems Inc. MP2489DQ-LF-P

Overview

MP2489DQ-LF-P from Monolithic Power Systems is a high-efficiency step-down white LED driver IC with 6V–60V input range, integrated 65V MOSFET, ≥1A output current capability, 202mV feedback reference voltage, and hysteretic control architecture. It regulates LED current via external high-side sense resistor and supports both PWM (1000:1 resolution) and analog dimming for automotive lighting, signage, and emergency illumination systems.

For engineers reviewing the MP2489DQ-LF-P datasheet, MP2489DQ-LF-P pinout, MP2489DQ-LF-P application, or MP2489DQ-LF-P equivalent, key selection criteria include input voltage range compatibility, thermal performance in QFN6 package, dimming interface flexibility (EN/DIM pin), and inherent open/short LED protection - all critical for robust LED system design.

Technical Context

The MP2489DQ-LF-P implements a fixed-frequency hysteretic control scheme that eliminates loop compensation while delivering fast transient response and stable current regulation across wide input voltages. Its internal 1.275V reference sets both enable threshold and current-sense reference scaling, enabling direct analog dimming via EN/DIM pin voltage (0.3V–2.5V).

Current regulation is achieved by maintaining the RS pin voltage at 202mV ±30mV relative to VIN, measured across an external high-side sense resistor. The device integrates thermal shutdown, open-LED detection, and short-LED protection - all implemented without external components.

Key Specifications

Pinout & Package

MP2489DQ-LF-P is housed in a thermally enhanced QFN6 (3mm × 3mm) package with exposed pad connected to GND. Pin numbering follows standard JEDEC MO-229 VEEA-2 outline; pin 1 marked by top-side dot or index area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2489DQ-LF-Z, the MP2489DQ-LF-P offers identical electrical performance at lower cost and qualification level, while the LT3476EFE#PBF trades single-string simplicity for multi-channel flexibility and higher dimming resolution - making it unsuitable as a direct replacement in high-input-voltage, single-output applications.

Availability

MP2489DQ-LF-P is available at Aetrix Electronics and suitable for automotive exterior lighting, emergency exit signage, industrial decorative lighting, and low-voltage halogen replacement requiring stable component supply across production lifecycles.

Supply support for MP2489DQ-LF-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 distribution through authorized partners.

The MP2489 belongs to MPS's high-voltage LED driver product line, engineered specifically for efficient, compact, and robust constant-current LED solutions in industrial, automotive, and architectural lighting applications.

FAQ

What is the maximum LED string voltage supported by MP2489DQ-LF-P?

The MP2489DQ-LF-P does not regulate output voltage directly - it regulates LED current. The maximum LED string voltage equals VIN minus the forward voltage drop across the internal MOSFET and external Schottky diode. With 60V input and typical 0.5V MOSFET drop + 0.4V diode drop, up to ~59V LED string voltage is achievable, limited only by input supply and component ratings.

Can MP2489DQ-LF-P operate with 12V AC input after rectification?

Yes - after full-wave rectification and bulk capacitance, 12V AC yields ~17V DC, well within the 6V–60V operating range. The device tolerates input ripple and transient spikes common in transformer-based supplies, and its hysteretic control maintains stable current regulation even with significant input voltage variation.

How is LED current set, and what resistor value gives 700mA output?

LED current is set by the external high-side sense resistor between IN and RS pins using R_SET = 202mV / I_LED. For 700mA, R_SET = 0.202V / 0.7A = 288.6 mΩ - a standard 287 mΩ (1% tolerance) resistor yields 703mA, within typical ±5% regulation accuracy.

Does MP2489DQ-LF-P require external compensation components?

No - the hysteretic control architecture eliminates the need for external compensation networks such as type-II or type-III error amplifier feedback loops. Stability is inherent across all operating conditions, simplifying design and reducing component count.

What thermal derating applies when operating above +25°C ambient?

Using θ_JA = 50°C/W for QFN6 on 4-layer PCB, maximum allowable power dissipation decreases linearly: P_D(MAX) = (150°C − T_A) / 50°C/W. At +85°C ambient, max dissipation drops to 1.3W - limiting continuous output current to ~1.1A assuming 0.5Ω R_DS(on) and typical losses.

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

Yes - the EN/DIM pin accepts logic-high signals up to 2.56V (max) and has an internal 45kΩ pull-up to 1.25V. A 3.3V GPIO can drive it directly for PWM dimming (with series resistor if needed to limit current), and analog dimming works with DAC outputs or resistive dividers scaled to 0.3–2.5V range.