Monolithic Power Systems Inc. EV171A-J-00A

Overview

EV171A-J-00A from Monolithic Power Systems is an evaluation board designed to demonstrate the MP171A primary-side constant voltage regulator in a buck topology, delivering 5 V / 50 mA output from universal 85–265 VAC input, with integrated 700 V MOSFET, <100 mW no-load consumption, and EN55022-compliant conducted EMI performance.

For engineers reviewing the EV171A-J-00A datasheet, EV171A-J-00A pinout, EV171A-J-00A application, or EV171A-J-00A equivalent, this board enables rapid validation of non-isolated offline CV regulation, surge immunity (IEC61000-4-5 Class 3), thermal shutdown behavior, and load transient response under real AC line conditions.

Technical Context

The EV171A-J-00A implements a fixed-frequency, primary-side regulated buck converter using the MP171AGJ IC in TSOT23-5 package. It eliminates optocouplers and secondary-side feedback by sampling output voltage via C1 and resistor divider (R1/R2), enabling accurate CV regulation across 85–265 VAC input.

EMI suppression relies on a CLC filter (C3–L1–C4) meeting EN55022 conducted limits, while RF1 provides inrush limiting and overcurrent protection. The board achieves 2 kV surge immunity per IEC61000-4-5 Class 3 and maintains stable 5 V output across 0–50 mA load with ≤50 mV peak-to-peak ripple.

Key Specifications

Availability

EV171A-J-00A is available at Aetrix Electronics and suitable for offline power supply prototyping, consumer appliance auxiliary supply design, and industrial control standby power development requiring stable component supply and fast-turn evaluation support.

Supply support for EV171A-J-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 a focus on efficiency, integration, and reliability in DC/DC, AC/DC, and motor driver solutions.

The MP171A product line delivers primary-side constant voltage regulation for non-isolated offline converters, targeting cost-sensitive, space-constrained applications where optocoupler-free feedback and low no-load power are critical.

FAQ

What topology does the EV171A-J-00A implement?

The EV171A-J-00A implements a buck topology using the MP171AGJ IC. It is configured with external components including L1, D3, C5, and the R1/R2 feedback network to deliver regulated 5 V output from 85–265 VAC input without secondary-side sensing or optocouplers.

Does the board meet international EMI standards?

Yes - the EV171A-J-00A meets EN55022 Class B conducted emissions requirements using its integrated CLC filter (C3–L1–C4) and passes radiated emissions testing per standard test setups. Full test plots are provided in Rev. 1.0 documentation on pages 7–8.

What protections are demonstrated on this board?

The board demonstrates MP171A's built-in protections: short-circuit protection (SCP), over-load protection (OLP), open-loop detection, thermal shutdown (TSD), and VCC under-voltage lockout (UVLO). Waveforms for SCP entry/recovery and open-loop events are shown on pages 9–10.

Can the EV171A-J-00A be used with other topologies?

Yes - while configured as a buck converter, the MP171A IC supports Buck-Boost, Boost, and Flyback topologies. The EV171A-J-00A schematic and layout are specific to buck; alternate configurations require redesign of power stage and feedback network per MP171A datasheet guidelines.

Is agency safety certification available for this board?

No - the EV171A-J-00A is an engineering prototype not certified to UL, CE, or other safety standards. Per documentation warning (page 2), all testing must use an isolation transformer for AC input, and it is not intended for end-product deployment without full safety qualification.

What is the role of RF1 on the board?

RF1 is a 39 Ω, 1 W fuse resistor that limits inrush current during AC power-up and provides overcurrent protection against catastrophic failures. It works with C3 and C4 to satisfy IEC61000-4-5 Class 3 (2 kV) surge immunity requirements.