Monolithic Power Systems Inc. MP4000DS-LF

Overview

MP4000DS-LF from Monolithic Power Systems is a constant-current LED driver controller for offline high-brightness white LED applications, implementing boundary conduction mode (BCM) with zero-current turn-on of an external MOSFET, 300 mV CS reference voltage, 110 kHz max switching frequency, and hiccup-mode short-circuit protection. It drives floating buck topologies in AC/DC LED lighting systems up to 12 W.

For engineers reviewing the MP4000DS-LF datasheet, MP4000DS-LF pinout, MP4000DS-LF application, or MP4000DS-LF equivalent, key selection considerations include its BCM operation for high efficiency without reverse-recovery loss, external MOSFET drive capability, dual-mode burst dimming (PWM/DC), low 0.9 mA operating current, and SOIC8 thermal performance at +125°C junction temperature.

Technical Context

The MP4000DS-LF operates exclusively in boundary conduction mode, regulating LED current via peak current sensing on the CS pin with a 300 mV ±15 mV reference, enabling precise I_LED = V_REF / (2 × R_sense). Zero-current detection is implemented through dV/dt sensing at the DRIVE pin using the MOSFET's Miller capacitance.

Burst dimming is supported via two configurations: DC input (0–2.4 V on DIM sets duty cycle linearly) or external PWM (100 Hz–2 kHz), with BOS pin configured either with a capacitor (for DC mode) or a 300 kΩ resistor (for PWM mode). UVLO activates at 7.4 V (rising) with 1 V hysteresis, and thermal shutdown triggers at 150°C with 30°C hysteresis.

Key Specifications

Pinout & Package

MP4000DS-LF is housed in an industry-standard SOIC8 package (5.0 mm × 6.2 mm, 1.27 mm pitch), with exposed pad not present and JEDEC MS-012 AA compliance. Thermal resistance θ_JA = 96 °C/W and θ_JC = 45 °C/W are measured per JESD51-7 on a 4-layer board.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current LED driver controller applications.

Compared with NCL30001DR2G and AL8862W7-13, MP4000DS-LF uniquely supports both analog and PWM burst dimming natively, delivers lower V_REF for higher current-sense accuracy, and provides external MOSFET drive for scalable power handling beyond 12 W with optimized thermal partitioning.

Availability

MP4000DS-LF is available at Aetrix Electronics and suitable for residential LED downlights, industrial area lighting, and automotive interior ambient lighting requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP4000DS-LF 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, founded in 1997 and headquartered in Kirkland, Washington.

The MP4000 product line targets offline LED lighting applications requiring high efficiency, accurate current regulation, and robust protection-designed specifically for universal-input AC/DC LED drivers in residential, commercial, and industrial environments.

FAQ

What is the minimum recommended sense resistor value for MP4000DS-LF?

The minimum sense resistor is determined by peak current limit and power dissipation. With V_REF = 300 mV and typical I_PEAK ≤ 1.5 A, R_sense ≥ 200 mΩ avoids exceeding 100 mW dissipation. Lower values risk thermal overload and inaccurate current regulation due to noise sensitivity on the CS pin.

Can MP4000DS-LF operate without a valley-fill PFC circuit?

Yes-MP4000DS-LF functions with or without valley-fill PFC. The controller regulates LED current independently; valley-fill is an optional front-end stage to improve power factor above 0.7. Its absence does not affect MP4000DS-LF operation but may cause non-compliance with energy regulations like ENERGY STAR.

Why is the TST pin required to be grounded?

TST is a factory test terminal with no user-accessible function. Leaving it unconnected risks undefined internal logic states and potential startup failure. Grounding TST ensures proper initialization of internal bandgap and oscillator circuits, as confirmed in MPS Application Note AN-107.

Does MP4000DS-LF support dimming below 5% brightness?

Yes-dimming down to ~1% is achievable using external PWM with ≥1 kHz frequency and precise duty-cycle control. At DC dimming, voltages below 120 mV yield ≤5% output; further reduction requires external signal conditioning to extend the analog range without violating the 0.9 V PWM low threshold.

What happens if the BOS pin is left floating?

A floating BOS pin causes unpredictable burst dimming behavior: the internal oscillator may oscillate erratically or stall, leading to inconsistent LED current regulation and potential overvoltage stress on the external MOSFET. Always tie BOS to GND via capacitor (DC mode) or 300 kΩ resistor (PWM mode).

Is MP4000DS-LF qualified for automotive AEC-Q100?

No-MP4000DS-LF is rated for industrial temperature range (–40°C to +85°C ambient) and lacks AEC-Q100 qualification. For automotive cabin lighting, it may be used in non-safety-critical ambient applications only if validated per customer-specific reliability testing; no guaranteed qualification data exists.

How does leading-edge blanking (LEB) interact with the CS pin during startup?

LEB disables CS comparator response for 200–450 ns after each DRIVE pulse edge, preventing false overcurrent trips caused by switching noise coupling into the sense resistor. During cold-start with large output capacitors, LEB ensures stable initial current ramp-up without premature shutdown.