Monolithic Power Systems Inc. EV024-10-S-00A

Overview

EV024-10-S-00A from Monolithic Power Systems is a universal-input (85–265 VAC), 5 V/2 A USB charger evaluation board built around the MP024-10 primary-side CC/CV flyback regulator IC. It integrates a 700 V MOSFET, supports discontinuous conduction mode with variable off-time control, delivers <30 mW no-load power consumption, and includes full protection suite (OVP, OCP, OTP, OLP, UVLO). It is designed for rapid prototyping of cost-sensitive, optocoupler-free AC/DC adapters.

For engineers reviewing the EV024-10-S-00A datasheet, EV024-10-S-00A schematic, EV024-10-S-00A test results, or EV024-10-S-00A bill of materials, this board enables immediate validation of MP024-10-based 5 V/2 A USB charging designs under real-world line and load conditions - including conducted EMI compliance (EN55022), short-circuit recovery, and no-load regulation behavior.

Technical Context

The EV024-10-S-00A implements a primary-side regulated flyback topology using the MP024-10 IC in SOIC8-7B package, eliminating secondary-side feedback and optocouplers. Its transformer (EPC17 core, 1.2 mH primary inductance, 115:6 turns ratio) enables precise CV/CC regulation via auxiliary winding sensing and variable off-time peak-current control.

Board-level design incorporates a π-filter (C1/L1/C2) for EN55022-compliant conducted EMI suppression, primary snubber (R3/C3/D1), secondary snubber (C7/R7), and programmable cable compensation via FB resistor divider (R5/R6). Protection behaviors - including OLP entry/recovery, short-circuit foldback, and thermal shutdown - are fully exercised and documented in test reports.

Key Specifications

Availability

EV024-10-S-00A is available at Aetrix Electronics and suitable for USB charger development, low-power AC/DC adapter qualification, and primary-side regulation topology evaluation requiring stable component supply and pre-validated safety margins.

Supply support for EV024-10-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 emphasis on efficiency, integration, and reliability across consumer, industrial, and automotive applications.

The EV024-10-S-00A belongs to MPS's evaluation board portfolio for primary-side regulation ICs, designed specifically to accelerate development of cost-optimized, regulatory-compliant offline chargers and adapters using their MP024 series.

FAQ

What is the purpose of the dummy load (R9) on the EV024-10-S-00A board?

R9 (5.1 kΩ) serves as a mandatory dummy load to maintain stable no-load output regulation. Without it, the MP024-10's minimum switching frequency limitation causes output voltage runaway due to insufficient energy transfer during light-load conditions - a known behavior in primary-side controllers relying on auxiliary winding feedback.

Does the EV024-10-S-00A include EMI filtering components compliant with EN55022 Class B?

Yes - the board integrates a complete π-filter (C1/L1/C2) and primary/secondary snubbers (R3/C3/D1 and C7/R7) that collectively meet EN55022 Class B conducted EMI limits on both line and neutral conductors at 115 VAC and 230 VAC, as validated in the official test report (Rev. 1.1, p. 11).

Can the EV024-10-S-00A be used for constant current (CC) battery charging applications?

Yes - the MP024-10 IC implements precise primary-side CC/CV regulation with programmable cable compensation. The board demonstrates stable 2 A constant current mode down to ~4.2 V output, making it suitable for Li-ion battery charging stages where isolated, low-cost CC control is required without secondary sensing.

What protection features are implemented and tested on this evaluation board?

All MP024-10 protections are fully exercised: over-voltage protection (OVP), over-current protection (OCP), over-temperature shutdown (OTP), open-loop protection (OLP), VCC under-voltage lockout (UVLO), and short-circuit foldback. Test waveforms for OLP entry/recovery and short-circuit power-on/recovery are provided in Figures 9–11 of the reference document.

Is the transformer on the EV024-10-S-00A board agency-certified for safety isolation?

The EPC17-based transformer meets reinforced insulation requirements: 3500 VAC (60 s) between primary and secondary, and 1500 VAC (60 s) between primary and core or secondary and core - satisfying IEC/UL 60950-1 and IEC/UL 62368-1 creepage/clearance and dielectric strength requirements for Class II equipment.

How is cable voltage drop compensated on this board?

Cable compensation is implemented via the MP024-10's internal circuitry and configured by the FB resistor divider (R5 = 30.9 kΩ, R6 = 13 kΩ). This adjusts the target output voltage upward under load to offset IR drop in USB cables, ensuring ≥4.75 V reaches the device port even at full 2 A - verified in load regulation tests.