Monolithic Power Systems Inc. EVHFC0310-S-00A

Overview

EVHFC0310-S-00A from Monolithic Power Systems is an evaluation board for the HFC0310 fixed-frequency flyback controller IC, configured to deliver regulated 12V/0.6A and 6V/0.1A outputs from 85–420VAC input. It implements peak current-mode control with programmable switching frequency up to 600kHz, active-burst mode for low standby power, and internal slope compensation. Used in AC/DC adapter and power meter reference designs.

For engineers reviewing the EVHFC0310-S-00A datasheet, EVHFC0310-S-00A pinout, EVHFC0310-S-00A application, or EVHFC0310-S-00A equivalent, this page provides verified board-level specifications, functional context, real-world test conditions (230VAC input, 25°C ambient), transformer winding ratios (N1:N2:N3:N4:N5 = 46:12:12:6:46), and component-level BOM traceability per MPS Rev.1.1 documentation.

Technical Context

The EVHFC0310-S-00A implements a fixed-frequency flyback topology using the HFC0310GS SOIC-8 controller, which employs peak current-mode control with 350ns leading-edge blanking and built-in 3ms soft-start. The board uses an EF20 core transformer with primary inductance of 2.5mH ±5% and five windings supporting dual-output regulation via opto-coupled feedback (PC817A + TL431K).

Input rectification uses four 1N4007 diodes in a bridge configuration; output rectification employs MURS320T3 (200V/3A) for the 12V rail and B1100 (100V/1A) for the 6V rail. Standby power is minimized via active-burst mode triggered below threshold output power, and EMI is reduced by frequency shaping (±3.5%) instead of fixed-frequency operation.

Key Specifications

Availability

EVHFC0310-S-00A is available at Aetrix Electronics and suitable for AC/DC adapter development, smart power meter design, and industrial switching charger prototyping requiring stable component supply, full BOM transparency, and validated reference performance.

Supply support for EVHFC0310-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 analog and power ICs, with expertise in DC/DC converters, LED drivers, motor drivers, and AC/DC controllers.

The HFC0310 product line targets high-voltage flyback applications in energy metering and universal-input AC/DC power supplies, emphasizing low standby power, robust EMI performance, and simplified loop compensation via current-mode architecture.

FAQ

What input voltage range does the EVHFC0310-S-00A support?

The board accepts 85–420VAC input, enabling testing across global mains voltages (e.g., 100VAC Japan, 230VAC EU, 277VAC North American lighting). Input rectification uses discrete 1N4007 diodes in bridge configuration, rated for 1000V PIV and 1A average current.

How are the two output rails regulated?

VOUT1 (12V) is regulated via opto-coupled feedback using PC817A and TL431K on the secondary side, referenced to the 12V winding (N2). VOUT2 (6V) derives from a separate secondary winding (N3) with local RC filtering but no dedicated regulation-its stability relies on coupled winding behavior and load sharing.

Does the board include EMI mitigation features?

Yes. The HFC0310 controller uses frequency shaping (±3.5%) instead of fixed-frequency operation, spreading spectral energy to reduce peak EMI. Additional suppression includes X1/Y1 safety capacitors (CX1, CY1), common-mode choke (LX1), and optimized PCB layout per MPS Rev.1.1 guidelines.

What is the role of the PRO pin on the HFC0310GS?

The PRO pin provides auto-restart protection: when pulled above 3.25V (internally pulled up), it triggers latch-off during overvoltage or overtemperature fault. Recovery requires power cycle or external reset-ensuring safe shutdown without manual intervention during abnormal operation.

Can the switching frequency be adjusted?

Yes. An external capacitor between the FSET pin and GND sets the operating frequency up to 600kHz. Omitting the capacitor enables the HFC0310's internal frequency-shaping function, which modulates switching frequency to lower conducted EMI and simplify filter design.

Is the transformer custom-wound, and what are its key parameters?

Yes. The EF20-core transformer has 2.5mH ±5% primary inductance and five isolated windings with exact turn ratio N1:N2:N3:N4:N5 = 46:12:12:6:46. Windings use insulated wire (T.I.W.) with margin tapes and TEFLON tubing for reinforced insulation-critical for 420VAC input safety compliance.