Monolithic Power Systems Inc. MP4056GK-Z

Overview

MP4056GK-Z from Monolithic Power Systems is a non-isolated, TRIAC-dimmable offline LED controller with integrated active PFC and boundary-conduction mode operation. It delivers accurate constant-current LED drive up to 50W in buck-boost topologies, supports warm-sunset color temperature control via DIM pin, and features adaptive leading/trailing-edge dimmer detection. Used in residential and commercial solid-state lighting with 230VAC/50Hz input.

For engineers reviewing the MP4056GK-Z datasheet, MP4056GK-Z pinout, MP4056GK-Z application, or MP4056GK-Z equivalent, key selection criteria include TRIAC dimmer compatibility depth, NTC-based thermal fold-back threshold (0.32–0.44 V shutdown), ZCD short-circuit protection (78–122 mV), internal 30 V/250 mΩ MOSFET, and SOIC-14/MSOP-10/SOIC-8 package options.

Technical Context

The MP4056GK-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) without secondary sensing. Its zero-current detection (ZCD) circuit triggers MOSFET turn-on at valley points to minimize switching loss and EMI.

Dimming is managed through dual-path phase-cut analysis: VMULT thresholds (0.08–0.47 V) distinguish leading/trailing-edge dimmers, while adaptive DP-mode detection (IDP_DET_LD = 140–220 µA) selects strong/weak pull-down currents (27–43 mA vs. 8–12 mA) for precise dimming curve matching.

Key Specifications

Pinout & Package

MP4056GK-Z is packaged in MSOP-10, with exposed pad for thermal performance. Pin functions are validated per MPS datasheet Rev.1.01 (2016), including dedicated NTC, DIM, DAMP, and ZCD terminals for system-level dimming, thermal management, and auxiliary winding sensing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4056GK-Z, MP4057GK-Z improves grid resilience and regulation accuracy but adds cost; BP57722D reduces integration to cut cost but sacrifices NTC protection and CCT control-making MP4056GK-Z optimal for thermally demanding, human-centric lighting designs.

Availability

MP4056GK-Z is available at Aetrix Electronics and suitable for residential LED lamps, commercial downlights, and industrial panel lighting requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP4056GK-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 over 20 years of leadership in LED driver innovation.

The MP4056 product line targets cost-sensitive, high-efficiency TRIAC-dimmable LED lighting systems requiring single-stage PFC, thermal fold-back, and warm-sunset dimming-addressing residential retrofit and commercial upgrade markets.

FAQ

What dimmer types does MP4056GK-Z support?

MP4056GK-Z supports both leading-edge (TRIAC) and trailing-edge (electronic low-voltage) dimmers. It uses adaptive detection based on MULT pin voltage thresholds and timing windows (tLEADING = 86–134 µs, tTRAILING = 388–602 µs) to auto-identify dimmer type and configure appropriate pull-down current sources (27–43 mA for leading edge, 133–167 mA for trailing edge).

How does the NTC thermal fold-back function work?

The NTC pin accepts a voltage divider formed by an NTC thermistor and pull-up resistor. When ambient temperature rises, NTC resistance drops, lowering the NTC pin voltage. At VL_NTC = 0.70–0.90 V, current fold-back begins; at VSD_NTC = 0.32–0.44 V, full shutdown occurs. Hysteresis (80–120 mV) prevents oscillation during temperature transitions.

Can MP4056GK-Z operate without an auxiliary winding?

No. The ZCD pin requires connection to an auxiliary winding to detect zero-current crossing for valley switching and OVP monitoring. The auxiliary winding also supplies VCC after startup. Without it, the IC cannot sustain operation beyond initial VCC charge and will fault due to missing ZCD signal and undervoltage.

What is the purpose of the DAMP pin?

The DAMP pin drives an external damping MOSFET to suppress voltage spikes during TRIAC commutation. This reduces EMI and prevents false triggering of the ZCD comparator. It operates synchronously with the main switching cycle and is essential for reliable dimmer compatibility in noisy AC environments.

Does MP4056GK-Z require external current sense resistors?

Yes. A sense resistor (Rs) must be placed between the S pin and GND to convert inductor current into a measurable voltage. The IC compares this voltage against internal clamps (VS_CLAMP_H = 1.97–2.17 V) and thresholds (VOCP = 2.70 V) for current limiting and OCP. Typical Rs values range from 0.2 Ω to 1 Ω depending on target LED current.

How is warm-sunset dimming implemented?

Warm-sunset dimming uses the DIM pin to output a PWM signal inverted relative to the TRIAC phase angle. As dimming level decreases (less conduction angle), DIM duty cycle increases, driving external circuitry to raise CCT (e.g., mixing warm/cool LEDs). This creates a natural "sunset" effect where light becomes warmer at lower brightness levels.

What protections are included and how do they recover?

MP4056GK-Z includes OVP, SCP, OCP, ZCD short-circuit, UVLO, and OTP. All protections trigger auto-restart: upon fault, switching halts, VCC discharges, and when VCC falls below VCCEN (6.55–7.45 V), the internal charger re-enables and the IC restarts the soft-start sequence.