Monolithic Power Systems Inc. MP4032-1GS-Z

Overview

MP4032-1GS-Z from Monolithic Power Systems is a TRIAC-dimmable, primary-side-controlled offline LED driver IC with an integrated 500V/1A MOSFET, operating in boundary-conduction mode to achieve >0.9 power factor and flicker-free dimming down to 5% brightness. It delivers up to 6W output power with real-current control-eliminating secondary feedback and current-sense resistors-enabling compact, cost-effective LED lighting for residential retrofit lamps.

For engineers reviewing the MP4032-1GS-Z datasheet, MP4032-1GS-Z pinout, MP4032-1GS-Z application, or MP4032-1GS-Z equivalent, this device is selected for single-stage AC/DC LED drivers requiring high PF, extended TRIAC dimming range, thermal/overvoltage/short-circuit protection, and SOIC8-7A surface-mount compatibility.

Technical Context

The MP4032-1GS-Z implements proprietary real-current control using primary-side sensing via the CS pin and multiplier-based line-voltage tracking on the MULT pin to regulate LED current without optocouplers or secondary shunt regulators. Its zero-current detection (ZCD) circuit triggers MOSFET turn-on at valley voltage, minimizing switching losses and EMI.

It integrates a 500V drain-charger startup path from the DRAIN pin to VCC, enabling fast start-up without auxiliary winding dependency during initial power-on. Protection functions include cycle-by-cycle current limiting (2.27V CS clamp), over-temperature shutdown (150°C junction), and output over-voltage detection via ZCD-based sampling with 5.3V threshold and 1.9μs blanking.

Key Specifications

Pinout & Package

MP4032-1GS-Z is housed in an SOIC8-7A package-a standard 8-pin, 3.9mm-wide surface-mount outline with exposed pad thermal enhancement and pin 7 NC (no connect).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4032-1GS-Z, MP4032-1GS offers identical performance in cut-tape format for low-volume builds, while MP4031-1GS-Z trades integration for higher power scalability-making MP4032-1GS-Z optimal for cost-sensitive, space-constrained ≤6W TRIAC-dimmable designs.

Availability

MP4032-1GS-Z is available at Aetrix Electronics and suitable for residential LED retrofits, commercial downlights, and industrial panel lighting requiring stable component supply, RoHS-compliant sourcing, and long-term lifecycle support.

Supply support for MP4032-1GS-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 expertise in DC/DC converters, LED drivers, and motor controllers.

The MP4032 product line targets cost-sensitive, single-stage AC/DC LED lighting applications-designed specifically to replace multi-chip solutions with integrated MOSFETs, real-current control, and extended TRIAC dimming capability.

FAQ

What is the maximum output power supported by MP4032-1GS-Z?

The MP4032-1GS-Z is rated for ≤6W output power under typical conditions (120VAC input, 350mA LED current, 18V output). This limit arises from its integrated 500V/1A MOSFET's R_DS(ON) and thermal dissipation capability in SOIC8-7A packaging-exceeding 6W risks thermal shutdown or reduced lifetime.

Does MP4032-1GS-Z require an external current-sense resistor?

Yes-it requires an external current-sense resistor between the CS pin and GND to set LED current. The value is calculated as R_s = (0.403V × N_p/N_s) / I_LED, where 0.403V is the internal reference voltage, and N_p/N_s is the transformer turns ratio. No secondary-side sensing is needed.

How does MP4032-1GS-Z achieve high power factor without a dedicated PFC controller?

It uses multiplier-based real-current control: the MULT pin samples rectified line voltage, generating a sinusoidal reference that shapes the primary peak current envelope to match input voltage phase-achieving >0.9 PF in single-stage flyback topology without active PFC stage.

Can MP4032-1GS-Z operate with trailing-edge (ELV) dimmers?

No-MP4032-1GS-Z is optimized for leading-edge (TRIAC) dimmers only. Its MULT pin dimming detection circuitry is calibrated for phase-cut waveforms with fast rise times; trailing-edge dimmers produce incompatible voltage profiles and will cause unstable or non-functional dimming.

What is the purpose of the NC pin (Pin 7) in the SOIC8-7A package?

Pin 7 is a no-connect terminal-internally unconnected and electrically isolated. It must remain unconnected on PCB layout to prevent parasitic coupling, noise injection, or potential latch-up. Leaving it floating is mandatory; soldering or routing to GND/VCC violates MPS layout guidelines.

How does the ZCD pin provide both zero-current detection and over-voltage protection?

ZCD monitors auxiliary winding voltage: a falling edge below 0.35V triggers MOSFET turn-on (zero-current detection), while exceeding 5.3V after 1.9μs blanking time latches OVP. Both functions share the same pin but use separate internal comparators and timing circuits-enabling dual functionality without extra pins.