Monolithic Power Systems Inc. MP4054AGJ-Z

Overview

MP4054AGJ-Z from Monolithic Power Systems is a primary-side-control, offline LED controller in TSOT23-8 package, integrating active PFC, valley switching, NTC thermal fold-back, and PWM dimming. It delivers ±2% LED current regulation across universal AC input (90–264VAC), achieves ≥0.9 power factor, and enables isolated flyback or non-isolated buck-boost LED drivers for residential and commercial lighting.

For engineers reviewing the MP4054AGJ-Z datasheet, MP4054AGJ-Z pinout, MP4054AGJ-Z application, or MP4054AGJ-Z equivalent, this IC supports real-current control without optocoupler or secondary feedback, provides 5.5µs minimum off-time for EMI control, and includes auto-restart, OVP, SCP, OTP, and cycle-by-cycle OCP for robust operation in cost-sensitive LED driver designs.

Technical Context

The MP4054AGJ-Z implements proprietary real-current control using primary-side sensing via CS/ZCD, eliminating secondary feedback while maintaining ≤2% line/load regulation. Its multiplier circuit accepts a half-wave sinusoidal signal from MULT to shape input current for ≥0.9 PF, with internal clamping at 2.0V to enforce cycle-by-cycle current limit.

Valley switching is triggered by dual zero-crossing detection on CS/ZCD-after blanking times of 1.2–2.1µs-reducing MOSFET turn-on loss and diode reverse-recovery noise. The NTC pin serves dual function: analog thermal fold-back (with VH_NTC = 1.23V, VL_NTC = 0.77V) and direct PWM dimming (>200Hz) by modulating VREF between full scale and minimum output.

Key Specifications

Pinout & Package

TSOT23-8 package with exposed pad for thermal dissipation; 0.65mm pitch, JEDEC MO-253 compliant. Pin 1 marked with dot; pin numbering counterclockwise from mark.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4054AGJ-Z, MP4056GJ-Z improves grid resilience but increases system cost, while BP57728E reduces component count at the expense of PFC compliance and integrated thermal safety-making MP4054AGJ-Z the balanced choice for globally certified, thermally robust LED drivers.

Availability

MP4054AGJ-Z is available at Aetrix Electronics and suitable for residential LED bulbs, commercial downlights, industrial high-bay fixtures, and smart streetlight drivers requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for MP4054AGJ-Z 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 MP4054A belongs to MPS's offline LED controller product line, engineered specifically for cost-sensitive, high-efficiency, and safety-certified AC/DC LED drivers that eliminate optocouplers while maintaining tight current regulation and PFC compliance.

FAQ

What is the minimum recommended bulk capacitor value for VCC in MP4054AGJ-Z?

The datasheet specifies a typical 4.7µF electrolytic capacitor on VCC, bypassed to GND. This value ensures reliable startup within the 190µs auto-start timer window and maintains stable operation during brown-out events. Smaller values risk insufficient hold-up time, causing erratic restarts under low-line conditions.

Can MP4054AGJ-Z operate 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 enables direct LED current sensing for superior regulation accuracy, though operation is limited to VIN > VOUT. Layout must minimize noise coupling to GND and FB traces.

How does the NTC pin support both thermal protection and PWM dimming?

The NTC pin uses the same analog input path: an internal 54µA pull-up generates voltage across an external NTC thermistor for thermal fold-back, while externally applied PWM signals >200Hz modulate VREF proportionally. A ceramic capacitor (2.2–4.7nF) is required for thermal mode but omitted for PWM dimming.

What is the purpose of the 1.2–2.1µs blanking time on CS/ZCD?

This blanking time suppresses false zero-crossing detection caused by parasitic ringing at MOSFET turn-off. It ensures accurate valley switching by delaying ZCD sampling until after transient decay-critical for maintaining high efficiency and low EMI in flyback converters.

Does MP4054AGJ-Z require an external compensation network?

Yes-the COMP pin requires an external RC network (typically 10kΩ + 10nF) to stabilize the current control loop. Incorrect compensation causes LED current ripple or instability; the datasheet provides design equations and layout guidelines for optimal phase margin.

How is output over-voltage protection implemented without direct output sensing?

OVP uses the auxiliary winding voltage, which scales with output voltage via turns ratio. When ZCD voltage exceeds 5.1V after blanking, the latch disables switching until VCC drops below UVLO. This eliminates need for optocoupler-based OVP while maintaining isolation integrity.

What is the maximum MOSFET voltage rating supported in MP4054AGJ-Z designs?

The IC itself does not limit MOSFET voltage; however, in 264VAC applications with 20% surge, peak bus voltage reaches ~450V. Designers typically select 600V or 650V MOSFETs-verified in MPS reference designs-to ensure margin against voltage spikes and ringing.