Monolithic Power Systems Inc. EV158-J-00A

Overview

EV158-J-00A from Monolithic Power Systems is a compact, single-sided evaluation board for the MP158 primary-side constant voltage regulator IC, configured in buck topology to deliver 5 V / 50 mA from 85–145 VAC input at 50/60 Hz, featuring integrated 500 V / 20 Ω MOSFET, <100 mW no-load power consumption, and compliance with EN55022 conducted EMI and IEC61000-4-5 Class 1 (0.5 kV) surge immunity.

For engineers reviewing the EV158-J-00A datasheet, EV158-J-00A pinout, EV158-J-00A application, or EV158-J-00A equivalent, this board enables rapid validation of MP158-based offline CV regulation in space-constrained consumer and home automation power supplies where optocoupler-free design, low standby loss, and robust EMI/surge performance are critical selection criteria.

Technical Context

The EV158-J-00A implements a non-isolated buck converter using the MP158GJ IC in TSOT23-5 package, with primary-side sensing via FB pin and internal peak-current control with frequency foldback. It uses a 1 mH SMD inductor (LPS6235_105MR), 2.2 µF/250 V X7T ceramic capacitor (C3) for LC filtering and surge energy absorption, and a 62 Ω/1 W fuse resistor (FR1) for inrush and fault protection.

Board-level design integrates discrete components including RS1J fast recovery diode (D3), three WSRGC10MH 1000 V/1 A diodes (D1/D2/D4), and precision resistor dividers (R1 = 5.1 kΩ, R2 = 4.99 kΩ) for output voltage sampling - all optimized to demonstrate MP158's optocouplerless CV regulation accuracy and thermal shutdown, OLP, SCP, and VCC UVLO protections.

Key Specifications

Availability

EV158-J-00A is available at Aetrix Electronics and suitable for home appliance power supplies, smart home automation modules, and low-power standby converters requiring stable component supply, rapid prototyping capability, and pre-validated EMI/surge performance.

Supply support for EV158-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 analog and power ICs, with core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MP158 product line delivers primary-side constant voltage regulation for offline AC/DC converters, targeting cost-sensitive, space-constrained consumer and home electronics where optocoupler elimination and low no-load loss are essential.

FAQ

What topology does the EV158-J-00A implement, and why is it significant?

The EV158-J-00A implements a non-isolated buck topology using the MP158 primary-side controller. This configuration eliminates the need for an optocoupler and secondary-side feedback circuitry, reducing BOM count and board area while maintaining tight 5 V output regulation across 85–145 VAC input. It demonstrates how MP158 achieves CV accuracy through internal peak-current sensing and FB pin voltage sampling.

Does the EV158-J-00A include safety isolation, and what precautions are required during testing?

No, the EV158-J-00A is a non-isolated evaluation board - its output shares ground with the AC input line. Per MPS documentation, all testing must be performed using an isolation transformer for the AC input to prevent shock hazard and ensure safe operation. The board is not agency-certified and is intended solely for engineering evaluation under controlled lab conditions.

Which protection features of the MP158 are demonstrated on this board?

The EV158-J-00A validates MP158's thermal shutdown (OTP), over-load protection (OLP), short-circuit protection (SCP), VCC under-voltage lockout (UVLO), and open-loop protection. These are implemented via internal circuitry and verified through load-step, short-circuit, and brown-out tests per the Quick Start Guide - no external components are needed to enable these protections.

Can the EV158-J-00A be modified to support boost or flyback topologies?

No - the EV158-J-00A is fixed as a buck application with specific component values (e.g., L2 = 1 mH buck inductor, D3 = freewheeling diode). While the MP158 IC itself supports boost, buck-boost, and flyback, implementing those requires different magnetics, snubbers, and layout changes not present on this board. Refer to MP158 datasheet Section 8 for alternate topology schematics.

What is the role of FR1 and C3 in surge and EMI performance?

FR1 (62 Ω/1 W fuse resistor) limits inrush current and provides overcurrent protection during faults, while C3 (2.2 µF/250 V X7T ceramic) forms an LC filter with L1 to suppress conducted EMI per EN55022. Together, they absorb and clamp surge energy per IEC61000-4-5 Class 1 (0.5 kV), eliminating need for external MOVs or TVS diodes in this design.

Is RoHS compliance confirmed for all components on the EV158-J-00A?

Yes - all listed BOM components, including MP158GJ (TSOT23-5), muRata/GRM capacitors, Yageo resistors, Wurth/Coilcraft inductors, and ZOWIE diodes, are RoHS-compliant and lead-free per MPS documentation and manufacturer part number cross-references. MPS confirms full RoHS adherence for the complete evaluation board assembly.