Monolithic Power Systems Inc. EV4078-S-00A

Overview

EV4078-S-00A from Monolithic Power Systems is a 30W single-stage flyback evaluation board implementing active PFC and primary-side regulation (PSR) for constant-voltage LED lighting and front-end pre-regulator applications. It accepts universal AC input (90–265VAC/50–60Hz), delivers 50V/600mA output, achieves >0.95 power factor at 230VAC full load, meets IEC61000-3-2 Class C and EN55022 conducted emission standards, and features integrated OCP, OVP, SCP, OTP, and brownout protection.

For engineers reviewing the EV4078-S-00A datasheet, EV4078-S-00A pinout, EV4078-S-00A application, or EV4078-S-00A equivalent, this board enables rapid validation of MP4078GS-based PSR-PFC converter designs-especially for smart LED drivers requiring ultra-low no-load consumption (40mW typical at 230VAC), high efficiency across load range, and compact 98mm × 38.5mm × 25mm form factor.

Technical Context

The EV4078-S-00A implements a single-stage offline flyback topology with integrated active PFC and PSR control via the MP4078GS SOIC-8 controller. It eliminates optocouplers and secondary feedback by sensing output voltage through an auxiliary winding, using cycle-by-cycle peak current limiting and maximum 65kHz switching frequency to regulate output under varying line and load conditions.

Input EMI filtering includes X-capacitor CX1, common-mode choke LCM1, and differential-mode LC filter (L1, C1, C2); surge protection uses MOV VAR1; and safety isolation is reinforced by Y-capacitor CY1 and transformer insulation rated to 3500VAC between primary and secondary sides.

Key Specifications

Availability

EV4078-S-00A is available at Aetrix Electronics and suitable for smart LED lighting design validation, front-end AC/DC pre-regulator prototyping, and PFC+PSR topology benchmarking requiring stable component supply and documented reference performance.

Supply support for EV4078-S-00A 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 power management ICs, with expertise in DC/DC converters, LED drivers, and AC/DC controllers for consumer, industrial, and automotive markets.

The EV4078-S-00A belongs to MPS's evaluation board product line targeting PSR-PFC AC/DC converter development, designed to accelerate time-to-test for engineers implementing cost-sensitive, space-constrained, and energy-efficient constant-voltage LED driver solutions.

FAQ

What is the role of the MP4078GS on the EV4078-S-00A board?

The MP4078GS is the core PSR-PFC controller in SOIC-8 package, providing primary-side regulation without optocoupler, active power factor correction, cycle-by-cycle current limiting, and integrated protections including OVP, OCP, SCP, OTP, and brownout detection-all coordinated through internal analog control loops and gate driver circuitry.

Can the EV4078-S-00A be used for constant-current LED applications?

No-the EV4078-S-00A is configured as a constant-voltage (50V) source per its schematic, bill of materials, and test reports; it lacks current-sense feedback path or CC regulation loop. For constant-current operation, a separate secondary-side CC controller or redesign of feedback network would be required.

What safety precautions are required when operating this evaluation board?

Per MPS documentation, the board is an engineering prototype without agency certification; all testing must use an isolation transformer for AC input. Exposed high-voltage nodes (L/N inputs, primary-side components) require insulated tools and proper grounding, and users must avoid contact during operation due to hazardous voltages exceeding 400VDC.

How is output voltage regulated without an optocoupler?

Regulation uses primary-side sensing via the transformer's auxiliary winding: R11 and R14 form a resistor divider that feeds the plateau voltage of the auxiliary winding into the FB pin of MP4078GS; the controller interprets this voltage as proportional to output voltage and adjusts duty cycle accordingly-enabling accurate ±1% CV regulation without secondary feedback.

Does the board include EMI filtering components for compliance testing?

Yes-the board integrates a full EMI filter: X-capacitor CX1, common-mode choke LCM1, differential-mode inductor L1 with capacitors C1/C2, and Y-capacitor CY1. Test data confirms compliance with EN55022 Class B conducted emissions using standard two-wire LISN measurement setup.

What is the thermal management approach for the main MOSFET Q1?

Q1 (SMK0870F, 700V/0.9Ω) is mounted on a dedicated TO-220 heatsink (HS1) attached to the PCB; thermal resistor RT1 monitors board temperature near the power stage, feeding into the MP4078GS's OTP circuit to throttle switching or shut down if temperature exceeds safe threshold.