Monolithic Power Systems Inc. MP2489DJ-LF-P

Overview

MP2489DJ-LF-P from Monolithic Power Systems is a 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 high-brightness LED strings in automotive lighting, emergency signage, and low-voltage halogen replacement systems using high-side current sensing.

For engineers reviewing the MP2489DJ-LF-P datasheet, MP2489DJ-LF-P pinout, MP2489DJ-LF-P application, or MP2489DJ-LF-P equivalent, key selection criteria include its 1000:1 PWM dimming resolution, thermal shutdown protection, open/short LED fault tolerance, and TSOT23-5 package compatibility with space-constrained LED driver designs.

Technical Context

The MP2489DJ-LF-P implements a fixed-frequency hysteretic control scheme that eliminates loop compensation while delivering fast transient response and stable LED current regulation via external high-side sense resistor. Its internal 1.275V reference sets both enable threshold and current-sense comparator trip point.

It supports dual dimming modes: analog dimming (0.3V–2.5V DC on EN/DIM pin linearly scales LED current from 25% to 200%) and PWM dimming (100Hz–2kHz square wave with 1000:1 resolution). The 202mV ±30mV feedback voltage minimizes power loss across the sense resistor.

Key Specifications

Pinout & Package

MP2489DJ-LF-P is housed in a TSOT23-5 package (3.0mm × 1.7mm × 0.9mm), featuring an exposed pad thermally connected to GND for enhanced heat dissipation in compact LED driver layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ2489DJ-AEC1, the MP2489DJ-LF-P offers identical performance at lower cost and qualification overhead for non-automotive applications; versus LT3476EFE#PBF, it delivers simpler implementation and higher integration for single-string designs but lacks multi-channel flexibility.

Availability

MP2489DJ-LF-P is available at Aetrix Electronics and suitable for automotive exterior lighting, emergency exit signage, low-voltage halogen replacement, and architectural accent lighting requiring stable component supply and RoHS-compliant packaging.

Supply support for MP2489DJ-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 core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MP2489 belongs to MPS's high-voltage step-down LED driver product line, engineered specifically for robust, high-efficiency white LED current regulation in industrial and transportation lighting where input voltage variation and fault resilience are critical.

FAQ

What is the maximum LED string voltage the MP2489DJ-LF-P can drive?

The MP2489DJ-LF-P does not directly limit LED string voltage; instead, it regulates current through the string. With a 60V max input and typical forward voltage of ~3.2V per white LED, it supports up to 18 LEDs in series (57.6V) while maintaining sufficient headroom for the internal MOSFET dropout and inductor DCR losses.

Can the MP2489DJ-LF-P operate without an external current-sense resistor?

No. The device requires an external high-side current-sense resistor (R_SENSE) between IN and RS pins to set and regulate LED current. The 202mV feedback reference voltage is measured across this resistor; omitting it disables current regulation and risks device damage due to uncontrolled current.

How does the EN/DIM pin function in analog versus PWM dimming modes?

In analog mode, a 0.3–2.5V DC voltage on EN/DIM linearly adjusts LED current from 25% to 200% of nominal. In PWM mode, a 100Hz–2kHz square wave applied to EN/DIM modulates average LED current proportionally to duty cycle, with internal 1.25V pull-up enabling clean switching between on/off states.

Is the TSOT23-5 package thermally adequate for 1A continuous operation?

Yes, but with PCB thermal design constraints. The TSOT23-5 package has θ_JA = 100°C/W; at 1A output and 24V input, typical power dissipation is ~0.5W, resulting in ~50°C junction rise above ambient. A 2-layer board with 1-in² copper pour under the exposed pad is recommended to maintain T_J < 125°C.

Does the MP2489DJ-LF-P require external compensation components?

No. Its hysteretic control architecture eliminates the need for external compensation networks such as type-II or type-III error amplifiers, RC filters, or phase-lead capacitors. This simplifies layout, reduces component count, and ensures inherent stability across all input/output conditions.

What protection features are built into the MP2489DJ-LF-P?

The device integrates thermal shutdown (150°C), open LED protection (disables switching if RS senses no current), short LED protection (shuts down if RS voltage exceeds VIN–5V), and input overvoltage clamp (65V absolute max on SW and IN pins).

Can the MP2489DJ-LF-P be used with AC input sources?

Not directly. It requires a DC input between 6V and 60V. For AC-powered applications (e.g., 12VAC halogen replacement), a bridge rectifier and bulk capacitor must first convert AC to regulated DC before connecting to the IN pin.