Monolithic Power Systems Inc. MP4033GK-Z

Overview

MP4033GK-Z from Monolithic Power Systems is a TRIAC-dimmable, primary-side-control offline LED controller with integrated active PFC, designed for isolated flyback LED drivers up to 50W. It delivers accurate LED current regulation using real-current control, operates in boundary-conduction mode, and supports analog dimming via PWM input or warm sunset color/brightness control via the DIM pin.

For engineers reviewing the MP4033GK-Z datasheet, MP4033GK-Z pinout, MP4033GK-Z application, or MP4033GK-Z equivalent, key selection criteria include TRIAC dimmer compatibility (leading/trailing edge), programmable NTC-based thermal fold-back, ZCD-based zero-current switching, internal MOSFET integration (30V BVDSS, 250 mΩ RDS(ON)), and SOIC-14/MSOP-10/SOIC-8 package options.

Technical Context

The MP4033GK-Z implements adaptive dimmer-type detection by analyzing MULT pin waveform timing (tLEADING ≤134 µs for leading edge; tTRAILING ≤602 µs for trailing edge) and voltage thresholds (VMULT_LD_LOW = 0.10 V, VMULT_TL_HIGH = 0.45 V). Its real-current control loop uses VREF = 0.414 V and primary-side sensing to derive LED current as I_LED ≈ (V_REF × N_sec) / (2 × R_s).

Boundary-conduction mode operation is enforced via ZCD-triggered turn-on with tZCD_LEB = 2.30 µs (typ), minimizing switching losses. Power factor correction is achieved through a multiplier circuit driven by rectified line voltage on MULT, shaping primary current to match line voltage phase with PF >0.9 at full load.

Key Specifications

Pinout & Package

MP4033GK-Z is packaged in MSOP-10, with exposed pad for thermal performance. Pin functions are validated per MPS MP4033 Rev. 1.0 datasheet (p.14).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4032GK-Z, MP4033GK-Z reduces component count and layout area via integrated 30V MOSFET but trades off maximum power capability; versus BP5778E, it delivers superior dimmer interoperability and PF performance at the cost of slightly higher system complexity.

Availability

MP4033GK-Z is available at Aetrix Electronics and suitable for residential LED downlights, commercial office troffers, and industrial high-bay fixtures requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for MP4033GK-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.

The MP4033 belongs to MPS's LED lighting controller product line, engineered specifically for TRIAC-dimmable, single-stage isolated LED drivers that demand high PF, deep dimming, and thermal resilience in compact form factors.

FAQ

What dimmer types does MP4033GK-Z support natively?

MP4033GK-Z supports both leading-edge (TRIAC) and trailing-edge (ELV) dimmers through adaptive detection: tLEADING ≤134 µs and tTRAILING ≤602 µs thresholds, plus voltage-based classification (VMULT_LD_LOW = 0.10 V, VMULT_TL_HIGH = 0.45 V). No external configuration is needed - detection occurs automatically at power-up.

How does the real-current control method eliminate secondary-side feedback?

Real-current control uses primary-side parameters - VREF = 0.414 V, transformer turns ratio (N_sec/N_aux), and sense resistor (R_s) - to calculate LED current as I_LED ≈ (V_REF × N_sec) / (2 × R_s). ZCD timing and boundary-mode operation ensure consistent energy transfer per cycle, enabling ±3% current regulation without optocouplers or secondary shunt regulators.

Can MP4033GK-Z be used without an NTC thermistor?

Yes - NTC functionality is optional. If the NTC pin is left unconnected or tied to GND, thermal fold-back is disabled and the device operates at full rated current. The internal clamp (VH_NTC = 1.20 V, VL_NTC = 0.80 V) ensures no false triggering; no pull-up or biasing is required for basic operation.

What protection features auto-restart after fault clearance?

All protections - output over-voltage (OVP), output short-circuit (SCP), winding short-circuit, ZCD pin short-circuit, supply UVLO, and over-temperature - feature auto-restart. After fault condition clears, VCC drops below VCCEN = 7.0 V, triggering internal recharge and resumption of normal operation within 3–5 switching cycles.

Is the internal MOSFET sufficient for 50W LED loads?

Yes - the integrated 30V/250 mΩ MOSFET supports up to 50W in typical isolated flyback configurations (e.g., 230VAC input, 24V/420mA output) when operated in boundary-conduction mode with proper heatsinking. Thermal resistance θJA = 150 °C/W (MSOP-10) limits junction rise to <85°C at 50W with 2 cm² copper pour.

How is warm sunset dimming implemented using the DIM pin?

Warm sunset dimming uses the DIM pin's programmable sink/source current (IDIM_SINK = 2.8 mA typ, IDIM_SOURCE = 3 mA typ) to drive external dummy loads or CCT-mixing FETs. The controller modulates DIM duty ratio synchronously with the dimming phase, enabling correlated color temperature (CCT) reduction from 4000K to 2700K as brightness decreases - all with one PWM input signal.