Monolithic Power Systems Inc. MP4027GJ-P

Overview

MP4027GJ-P from Monolithic Power Systems is a primary-side-control, offline LED controller in TSOT23-8 package, integrating active PFC, valley switching, NTC thermal foldback, and PWM dimming. It delivers <2% line/load regulation, ≥0.9 power factor across universal AC input (90–264VAC), and real-current control without secondary feedback-enabling isolated flyback LED drivers for residential lighting with 350mA output current and 20V output voltage.

For engineers reviewing the MP4027GJ-P datasheet, MP4027GJ-P pinout, MP4027GJ-P application, or MP4027GJ-P equivalent, key selection criteria include primary-side OCP threshold (2.46V), VCC UVLO (9.5V turn-off), NTC voltage thresholds (0.39V shutdown, 1.23V high), COMP clamp range (1.5V–4.75V), and GATE drive capability (0.8A source / –1A sink).

Technical Context

The MP4027GJ-P implements proprietary real-current control using primary-side sensing via CS/ZCD, eliminating optocouplers and secondary-side components. Its multiplier-based PFC architecture accepts a half-wave sinusoidal reference at MULT to shape input current, achieving ≥0.9 PF by dynamically scaling peak primary current per line cycle.

Valley switching is triggered by dual zero-crossing detection on CS/ZCD after blanking intervals (0.8–2.1μs), reducing MOSFET turn-on loss and EMI. Protection logic integrates cycle-by-cycle OCP (2.46V threshold), output OVP (5.1V ZCD threshold with 0.8–1.6μs blanking), brown-out detection (298mV MULT peak, 42ms hold time), and thermal shutdown (150°C with 25°C hysteresis).

Key Specifications

Pinout & Package

MP4027GJ-P is housed in a thermally enhanced TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), optimized for compact LED driver PCB layouts with exposed pad for improved heat dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar primary-side LED controller applications.

Compared with MP4027GJ-P, MP4026GJ-Z omits thermal and dimming features but matches core control performance, while BP5778E sacrifices PFC and protection depth for lower BOM cost-making MP4027GJ-P the sole choice for safety-certified, thermally robust, and dimmable universal-input LED drivers.

Availability

MP4027GJ-P is available at Aetrix Electronics and suitable for residential LED lamps, commercial downlights, and industrial panel lighting requiring stable component supply, long-lifecycle assurance, and RoHS-compliant manufacturing.

Supply support for MP4027GJ-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.

The MP4027 belongs to MPS's offline LED controller product line, engineered specifically for cost-sensitive, high-efficiency, safety-certifiable primary-side regulated lighting systems with integrated PFC and comprehensive fault protection.

FAQ

What is the purpose of the MULT pin, and how is it connected?

The MULT pin receives a scaled-down half-wave rectified AC line voltage via a resistor divider, providing the internal multiplier with a sinusoidal reference for active PFC and brown-out detection. It connects between the rectified bus and GND through two resistors, with optional Zener-based THD improvement circuitry for high-line operation.

How does the MP4027GJ-P achieve real-current control without secondary feedback?

It calculates LED current from primary-side parameters: the feedback reference voltage (0.413V), transformer turns ratio (N), and primary current-sense resistor (RS), using the formula ILED ≈ (0.413 × N) / (2 × RS). This eliminates optocouplers and secondary-side components while maintaining ±2% regulation accuracy.

Can the MP4027GJ-P be used in non-isolated topologies?

Yes-it supports low-side buck-boost and high-side buck/buck-boost configurations. In high-side buck, the FB pin directly senses LED current for precise regulation; in low-side buck-boost, it leverages the same control architecture with tapped inductor or 1:1 winding for improved PF and efficiency.

What protection features are integrated, and how do they respond to faults?

Integrated protections include OVP (latched shutdown at 5.1V ZCD), SCP (auto-restart at ~5kHz), primary-side OCP (2.46V latch), brown-out (COMP forced to zero for 42ms), OTP (150°C shutdown with 25°C hysteresis), and UVLO (9.5V turn-off). All trigger auto-restart after VCC drops below UVLO threshold.

What is the recommended layout practice for the CS/ZCD pin?

A 10pF ceramic capacitor must be placed directly between CS/ZCD and GND to suppress high-frequency noise. Additionally, a 1kΩ resistor should be added between CS/ZCD and the ZCD divider node to minimize RC delay effects on current-sensing accuracy and zero-crossing timing.

Does the MP4027GJ-P support both analog and PWM dimming?

It supports PWM dimming exclusively via the NTC pin with signals >200Hz; analog dimming is not implemented. The internal circuitry maps PWM duty cycle to VREF modulation, enabling linear LED current adjustment from full scale down to minimum output set by gate minimum on-time.

What is the function of the auto-restart timer, and when is it activated?

The 190µs auto-restart timer initiates GATE turn-on if the ZCD signal fails to trigger within that window after MOSFET turn-off-preventing system lockup during transient ZCD failures or transformer saturation. It operates independently of other protections and resets on each switching cycle.