Monolithic Power Systems Inc. MP4056GS-Z

Overview

MP4056GS-Z from Monolithic Power Systems is a non-isolated, TRIAC-dimmable offline LED controller with integrated active PFC, designed for single-stage buck-boost LED drivers up to 50W. It operates in boundary-conduction mode, delivers accurate LED current regulation (±3% typical), supports adaptive leading/trailing-edge dimmer detection, and features an internal low-side MOSFET (30V BVDSS, 250 mΩ RDS(ON)). It enables warm sunset dimming via dedicated DIM pin control in residential lighting systems.

For engineers reviewing the MP4056GS-Z datasheet, MP4056GS-Z pinout, MP4056GS-Z application, or MP4056GS-Z equivalent, key selection criteria include TRIAC compatibility depth (down to 5% conduction angle), programmable NTC-based thermal fold-back, ZCD-based zero-current switching timing, and VCC auto-restart behavior under fault conditions.

Technical Context

The MP4056GS-Z implements real-current control using a multiplier-driven current reference derived from rectified AC line voltage on the MULT pin, enabling high power factor (>0.9 at full load) and sinusoidal input current. Its boundary-conduction mode operation minimizes switching losses by triggering MOSFET turn-on precisely at inductor current zero-crossing, detected via the ZCD pin with 1.9–3.36 µs blanking.

Dimming functionality combines phase-cut detection (VMULT_ON/VMULT_OFF thresholds: 0.26–0.30 V / 0.08–0.12 V) with adaptive pull-down current sourcing (133–167 mA for trailing-edge, 27–43 mA for leading-edge) on the D pin, while the DIM pin provides complementary PWM-controlled brightness/temperature modulation synchronized to TRIAC phase angle.

Key Specifications

Pinout & Package

MP4056GS-Z is packaged in SOIC-8, with pin functions validated per MPS Rev.1.01 datasheet (Nov. 2016). All pins are electrically defined and functionally distinct; no NC pins are assigned in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCL30000 and AL1676, MP4056GS-Z uniquely integrates a low-side MOSFET, adaptive dimmer detection, and dedicated DIM pin for warm sunset-enabling higher integration, deeper dimming, and tunable white control in a single SOIC-8 package.

Availability

MP4056GS-Z is available at Aetrix Electronics and suitable for residential LED retrofit lamps, commercial downlights, and industrial task lighting requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for MP4056GS-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 core expertise in DC/DC conversion, LED drivers, and motor control.

The MP4056 belongs to MPS's offline LED controller product line, engineered specifically for cost-sensitive, high-efficiency, TRIAC-dimmable lighting applications demanding single-stage integration, PFC compliance, and robust fault protection.

FAQ

What dimmer types does MP4056GS-Z support?

MP4056GS-Z supports both leading-edge (TRIAC) and trailing-edge (electronic low-voltage) dimmers through adaptive detection based on MULT pin voltage thresholds and timing windows (tLEADING = 86–134 µs, tTRAILING = 388–602 µs). It achieves deep dimming down to 5% conduction angle with minimal pop-on/pop-off and no audible noise across major dimmer brands including Lutron and Leviton.

How does the internal MOSFET affect PCB layout and thermal design?

The integrated 30V, 250 mΩ low-side MOSFET eliminates external switch placement but requires careful thermal pad design on the SOIC-8 package: a minimum 12 mm² copper pour with 4+ thermal vias to inner ground layers is recommended to maintain TJ < 125°C at 50W output. The device's θJA of 96°C/W assumes JEDEC-standard 4-layer board; derating is required for 2-layer layouts.

Can MP4056GS-Z be used without an NTC thermistor?

Yes-NTC connection is optional. When left unconnected, the NTC pin floats and thermal fold-back is disabled; the IC operates at full rated current. If connected, a 10 kΩ NTC thermistor is recommended, with fold-back initiating at VL_NTC (0.7–0.9 V) and fully active at VH_NTC (1.14–1.36 V); shutdown occurs below VSD_NTC (0.32–0.44 V).

What is the role of the DAMP pin, and how is it implemented?

The DAMP pin drives an external MOSFET to suppress voltage spikes during TRIAC commutation, reducing EMI and preventing false triggering. It sources up to 450 µA with 13–16.5 V clamp; typical implementation uses a 2N7002-level-shifter FET with 10 kΩ gate resistor. No damping is required for trailing-edge dimmers, and the pin may be left unconnected in those cases.

How does the DIM pin enable warm sunset dimming?

The DIM pin outputs a PWM signal whose duty cycle is inversely proportional to TRIAC conduction angle: as dimming reduces LED current, DIM duty increases to drive a warm-white LED string or dummy load. This enables correlated color temperature shift from cool to warm white without external MCU, using only passive RC filtering and standard optocoupler feedback.

Is MP4056GS-Z compliant with IEC 61000-3-2 Class C?

Yes-when configured per MPS EV4056-K-00B reference design (230 VAC/50 Hz input, 36 V/167 mA output), MP4056GS-Z achieves >0.9 power factor and meets IEC 61000-3-2 Class C harmonic current limits for lighting equipment. Compliance requires proper MULT divider ratio, ZCD auxiliary winding turns, and input EMI filter design per Section 4 of the datasheet.