Monolithic Power Systems Inc. EV020A-5-S-01B

Overview

EV020A-5-S-01B from Monolithic Power Systems is an evaluation board for the MP020A-5 primary-side-regulated flyback controller, enabling optocoupler-free 12V/0.65A and 5V/50mA outputs from universal AC input (85–265VAC, 50/60Hz) in small home appliance power supplies. It integrates a 700V MOSFET, achieves >80% full-load efficiency, meets EN55022 conducted EMI and IEC61000-4-5 surge immunity, and includes OVP, OCP, OTP, and VCC UVLO protections.

For engineers reviewing the EV020A-5-S-01B datasheet, EV020A-5-S-01B pinout, EV020A-5-S-01B application, or EV020A-5-S-01B equivalent, this board supports rapid validation of primary-side regulation in cost-sensitive, low-power AC/DC designs requiring compact layout, low no-load consumption (100mW), and natural spectrum shaping for EMI compliance.

Technical Context

The EV020A-5-S-01B implements a single-stage flyback topology with primary-side control, eliminating secondary feedback components and reducing BOM count. It uses variable off-time, peak-current-mode control and samples output voltage via the transformer's auxiliary winding (N_{p_au}:N_s = 15:16) to achieve precise CC/CV regulation without optocouplers.

Its circuit includes a π-filter (C1–L1–C2) for EN55022 compliance, a snubber network (R2–R3–D1–C3) to suppress drain-voltage spikes, and Y-capacitor CY1 for common-mode noise suppression. The 5V rail is generated via L78L05A LDO from the 12V output, ensuring stable auxiliary supply under load transients.

Key Specifications

Availability

EV020A-5-S-01B is available at Aetrix Electronics and suitable for home appliance power supply development, cell phone charger reference design, and handheld electronics adapter qualification requiring stable component supply, fast prototyping turnaround, and documented EMI/surge performance.

Supply support for EV020A-5-S-01B 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 a focus on energy-efficient DC/DC and AC/DC solutions for consumer, industrial, and automotive markets.

The EV020A-5-S-01B belongs to MPS's primary-side regulation evaluation platform family, designed to accelerate adoption of integrated offline controllers that reduce system cost, size, and design complexity in sub-10W universal-input power supplies.

FAQ

What is the role of the MP020A-5GS IC on this board?

The MP020A-5GS is a primary-side-regulated offline controller with integrated 700V MOSFET, used to regulate both 12V and 5V outputs without secondary feedback. It samples auxiliary winding voltage for precise constant-voltage control and implements cycle-by-cycle current limiting and thermal shutdown for safety-critical operation.

Can the EV020A-5-S-01B be used for 60Hz-only applications?

Yes - the board is explicitly rated for 50Hz/60Hz operation across its full 85–265VAC input range. Transformer T1 and controller timing parameters are designed for dual-frequency compatibility, and no configuration changes are required when switching between 50Hz and 60Hz mains inputs.

How is the 5V output generated and regulated?

The 5V output is derived from the 12V rail using the L78L05A linear regulator (U3). It is not independently regulated by the MP020A-5GS but relies on the stability of the 12V output and the LDO's dropout performance (≤1.7V typical), delivering up to 50mA with ±2% output tolerance and thermal foldback protection.

Does this board include isolation and safety certification?

No - the EV020A-5-S-01B is an engineering prototype evaluation board, not agency-certified. It incorporates reinforced insulation (3000VAC PRI–SEC, 500VAC PRI–core) per transformer specs and meets IEC61000-4-5 surge immunity, but formal UL/EN62368-1 certification requires end-product-level testing and approval.

What transformer is used, and is it replaceable?

The board uses EE16 core transformer T1 (Wurth 7508110328 or Emei FX0303) with 2.48mH primary inductance, 184:15:16 turns ratio (N_p:N_{p_au}:N_s), and triple-insulated secondary winding. It is socketed and replaceable; alternative windings must maintain leakage inductance ≤60μH and inter-winding isolation ratings to preserve EMI and safety performance.

Is there a recommended heatsink or thermal management guidance?

No external heatsink is required - the MP020A-5GS operates in discontinuous conduction mode (DCM) with low junction temperature rise (<35°C above ambient at full load, measured per Rev.1.0 test report). PCB copper area around U1 drain pad (Pin 8) and thermal vias to inner layers provide sufficient passive cooling for continuous operation.