Monolithic Power Systems Inc. EV157-S-00A

Overview

EV157-S-00A from Monolithic Power Systems is an evaluation board designed to demonstrate the MP157GS primary-side constant-voltage offline regulator IC in a Buck topology, delivering 12 V at 350 mA (4.2 W) across 85–265 VAC input, with >75% average efficiency and EN55022-compliant conducted EMI performance.

For engineers reviewing the EV157-S-00A datasheet, EV157-S-00A pinout, EV157-S-00A application, or EV157-S-00A equivalent, this board enables rapid validation of primary-side regulation without optocoupler, surge resilience (1000 V L-N), and integrated protection features including open-loop, short-circuit, over-load, and thermal shutdown.

Technical Context

The EV157-S-00A implements a discontinuous conduction mode (DCM) Buck converter using the MP157GS IC, which integrates a 500 V/10 Ω MOSFET and internal high-voltage current source for self-biased operation. It supports universal AC input and achieves <100 mW no-load power consumption.

Key control functions include frequency foldback, peak current compression, 400 ns leading-edge blanking, and timer-based over-load protection with auto-restart thermal shutdown. The board's layout and component selection (e.g., 10 µF/400 V input capacitors C4/C5) are optimized to pass 1000 V surge testing per IEC 61000-4-5.

Key Specifications

Availability

EV157-S-00A is available at Aetrix Electronics and suitable for home appliance control modules, industrial sensor interface power supplies, and consumer electronics standby power designs requiring stable component supply, fast prototyping cycles, and regulatory-compliant AC/DC conversion.

Supply support for EV157-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP157 product line targets ultra-low-noise, optocoupler-free offline regulators for cost-sensitive, space-constrained AC/DC applications-emphasizing primary-side control accuracy, surge robustness, and energy efficiency compliance.

FAQ

What topology does the EV157-S-00A implement?

The EV157-S-00A implements a Buck topology using the MP157GS IC. Its schematic confirms input rectification, bulk capacitance (C4/C5), flyback diode D5 (STTH1R06), and output filter (L2, C6), configured specifically for step-down conversion from rectified AC to regulated 12 V DC.

Does the board support other topologies beyond Buck?

Yes-the underlying MP157GS IC supports Buck, Buck-Boost, Boost, and Flyback topologies. However, the EV157-S-00A board is fixed as a Buck implementation; alternate topologies require redesign of transformer/inductor, feedback network, and output rectification per MPS AN-109 application note.

What protections are implemented on the EV157-S-00A?

The board implements open-loop protection (via FB pin monitoring), short-circuit protection (current limiting + auto-restart), over-load protection (timer-based foldback), and thermal shutdown (with hysteresis). These derive directly from MP157GS internal circuitry and are validated in test reports on pages 5–7 of the reference document.

Can the EV157-S-00A meet 2 kV surge requirements?

Yes-with hardware modifications: replace F1 (10 Ω/1 W) with SS-5-2A fuse, add MOV RV1 (TVR14431), and series resistor R8 (39 Ω). This upgraded configuration passes 2000 V L-N surge per IEC 61000-4-5, as documented on page 8 of the reference design guide.

Is the MP157GS IC on this board RoHS-compliant?

Yes-MP157GS is lead-free and RoHS-compliant, as confirmed in the "All MPS parts are lead-free and adhere to the RoHS directive" statement on page 2 of the reference document. The EV157-S-00A board uses only RoHS-compliant passives and semiconductors per its BOM.

What is the physical size of the EV157-S-00A board?

The board measures 4.5 cm × 2.5 cm × 1.7 cm (L × W × H), making it suitable for compact prototyping and integration into space-constrained enclosures. Its small footprint aligns with the "Smallest Energy Efficient Off-line Regulator" branding in the title block.