Monolithic Power Systems Inc. EV9989-S-00A

Overview

EV9989-S-00A from Monolithic Power Systems is an evaluation board for the MP9989GS synchronous rectifier IC, designed to replace diode rectifiers in flyback converters. It integrates a 100V/10mΩ MOSFET, regulates forward voltage drop to 40mV, enables self-powered operation without auxiliary winding, and supports DCM, CCM, and quasi-resonant modes - validated in laptop adapter and USB PD charger designs.

For engineers reviewing the EV9989-S-00A datasheet, EV9989-S-00A pinout, EV9989-S-00A application, or EV9989-S-00A equivalent, this board provides rapid validation of MP9989GS performance in high-efficiency, low-output-voltage flyback topologies with no auxiliary winding dependency.

Technical Context

The EV9989-S-00A implements the MP9989GS IC in a functional flyback synchronous rectification configuration, with VS, VD, and VDD pins connected via 1.0mm pitch headers for direct integration into primary-side-controlled flyback circuits. Its ringing detection circuit prevents false turn-on during DCM transitions, and the internal 100V MOSFET operates with 40mV regulated forward voltage drop.

This board supports both high-side and low-side rectification setups, eliminates auxiliary winding requirements, and maintains stable regulation down to 0V output - enabling compliance with Energy Star efficiency standards in compact AC/DC adapters.

Key Specifications

Availability

EV9989-S-00A is available at Aetrix Electronics and suitable for laptop adapter development, USB PD charger qualification, and high-efficiency flyback converter prototyping requiring stable component supply and fast-turnaround evaluation support.

Supply support for EV9989-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 distribution.

The MP9989 product line targets high-efficiency AC/DC secondary-side synchronous rectification, specifically engineered to eliminate auxiliary windings and improve light-load efficiency in compact, low-output-voltage flyback power supplies.

FAQ

What is the primary function of the EV9989-S-00A evaluation board?

The EV9989-S-00A is a fully assembled, ready-to-use evaluation board for the MP9989GS synchronous rectifier IC. It allows engineers to validate the IC's performance - including 40mV forward voltage regulation, auxiliary-winding-free startup, and ringing-immune turn-off - directly in a flyback converter without custom PCB design.

Can EV9989-S-00A be used for both high-side and low-side synchronous rectification?

Yes. The board's VS, VD, and VDD header connections support either high-side or low-side placement in the flyback secondary circuit. Its self-powered architecture eliminates auxiliary winding dependency, making it equally viable for both configurations as confirmed in MPS Application Note AN-9989.

Does the board include all necessary passive components for immediate testing?

Yes. The BOM includes C1 (470nF/25V X7R), C2 (2.2nF/250V X7R), R1 (300Ω), R2/R3 (20Ω each), and the MP9989GS in SOIC-8 - all populated on the 2.2 cm × 2.2 cm PCB. No additional components are required to evaluate basic functionality.

What flyback control modes does EV9989-S-00A support out-of-the-box?

The board supports discontinuous conduction mode (DCM), continuous conduction mode (CCM), and quasi-resonant (QR) operation - verified using standard flyback controllers like MP6908 and MP6920. Ringing detection ensures reliable turn-off across all three modes without external timing adjustments.

Is EV9989-S-00A RoHS-compliant and lead-free?

Yes. All components on the board - including the MP9989GS IC, Murata and TDK capacitors, and Yageo resistors - are lead-free, halogen-free, and compliant with the EU RoHS directive, consistent with MPS's green manufacturing policy published on monolithicpower.com/quality.