Monolithic Power Systems Inc. MP4050AGS-P

Overview

MP4050AGS-P from Monolithic Power Systems is a non-isolated, constant-current LED driver IC with an integrated 500V/8Ω MOSFET, designed for AC/DC and DC/DC high-brightness LED bulb replacement. It delivers precise 115mA output current from universal AC input (85–265VAC) or DC input, operates at >22kHz to suppress audible noise, and features thermal current foldback starting at 145°C and shutdown at 160°C. It targets cost-sensitive, space-constrained general illumination applications.

For engineers reviewing the MP4050AGS-P datasheet, MP4050AGS-P pinout, MP4050AGS-P application, or MP4050AGS-P equivalent, key selection criteria include its integrated HV MOSFET breakdown rating, VCC UVLO thresholds (4.1–4.75V), PRO over-voltage protection (2.0V typ), thermal foldback behavior, and SOIC-8 package thermal resistance (θJA = 96°C/W).

Technical Context

The MP4050AGS-P implements a high-side buck topology with internal averaging current feedback, using SOURCE pin voltage sensing across an external resistor to regulate average LED current. Its control loop enforces minimum off-time (4.7μs) and maximum on-time (25μs) to maintain DCM operation above 22kHz under normal conditions.

Startup is managed by an internal high-voltage current source drawing from DRAIN, enabling direct connection to rectified AC line without auxiliary winding. Protection logic integrates open LED detection via PRO pin (2.0V OVP threshold), short-circuit response via frequency reduction, and thermal shutdown with 50°C hysteresis (160°C trip, 110°C recovery).

Key Specifications

Pinout & Package

MP4050AGS-P is housed in an SOIC-8 package with exposed pad for thermal enhancement. Pin 1 (VCC) supplies control circuitry; Pin 2 (PRO) monitors open LED faults; Pin 3 (GND) serves as signal and gate-drive reference; Pin 4 (SOURCE) connects to current-sense resistor and MOSFET source; Pin 5 and Pin 7 (DRAIN) connect to HV input and internal MOSFET drain; Pins 5, 6, and 8 are no-connect terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4050AGS-P, MP4050AGJ-P trades thermal performance for size, while MPQ4050AGS-P adds automotive qualification without altering core functionality-enabling direct substitution only where environmental rigor or footprint dictates.

Availability

MP4050AGS-P is available at Aetrix Electronics and suitable for smart LED bulbs, industrial panel lighting, and architectural accent lighting requiring stable component supply, consistent parametric performance, and long-lifecycle availability.

Supply support for MP4050AGS-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, headquartered in Kirkland, Washington, with global design and support centers.

The MP4050A product line delivers highly integrated, non-isolated LED drivers targeting cost-sensitive, space-constrained retrofit lighting solutions-emphasizing single-chip simplicity, thermal resilience, and universal AC input compatibility.

FAQ

What is the maximum recommended LED string voltage for MP4050AGS-P?

The MP4050AGS-P supports output voltages up to 40V in typical applications, as validated in the datasheet's 13-LED series configuration (115mA, 40V). Exceeding this requires verifying inductor saturation, freewheeling diode reverse voltage rating (>500V), and thermal margin under worst-case line and load conditions.

Can MP4050AGS-P operate from a 12V DC input?

Yes-MP4050AGS-P supports DC input operation. However, the internal HV startup current source is inactive below ~100V; VCC must be supplied externally (e.g., via bias winding or auxiliary supply) to ensure reliable startup and regulation at low DC input.

How does the thermal foldback function interact with over-temperature shutdown?

Foldback begins at 145°C, reducing LED current to limit power dissipation; shutdown occurs at 160°C, halting switching until junction cools to 110°C. This two-stage response prevents thermal runaway while allowing graceful degradation rather than abrupt failure.

What is the purpose of the PRO pin's 32μs time constraint?

The 32μs comparator delay on the PRO pin filters out transient voltage spikes during MOSFET switching, ensuring open LED detection only occurs when sustained over-voltage (>2.0V) persists-preventing false triggers from EMI or diode reverse recovery noise.

Is an external freewheeling diode required, and what specifications are critical?

Yes-an external ultrafast diode (t_rr < 75ns) rated ≥500V and ≥2× output current is mandatory. Slow diodes cause excessive current spikes during startup and reduce efficiency; WUGC10JH or EGC10GH are validated alternatives per the datasheet.

Does MP4050AGS-P support dimming, and if so, how?

The MP4050AGS-P does not include native PWM or analog dimming interfaces. Dimming must be implemented externally-e.g., by modulating the AC input with TRIAC phase-cut or using a separate DC enable signal that controls VCC supply to force on/off cycling.

What is the minimum recommended VCC bypass capacitance?

A minimum 4.7μF ceramic or low-ESR electrolytic capacitor is recommended between VCC and GND. Smaller values may cause UVLO oscillation during transients; larger values improve hold-up but increase start-up time and cost.