Monolithic Power Systems Inc. EV9928-F-00B

Overview

EV9928-F-00B from Monolithic Power Systems is an evaluation board designed to demonstrate the MP9928 synchronous step-down controller, a 6–60V input, 5V/7A output current-mode PWM controller with programmable frequency (100–1000 kHz), dual N-MOSFET drive capability, and integrated OVP/OCP/thermal shutdown protection. It implements a TSSOP20-EP packaged MP9928GF IC for industrial PoE power supplies and USB DCP applications.

For engineers reviewing the EV9928-F-00B datasheet, EV9928-F-00B pinout, EV9928-F-00B application, or EV9928-F-00B equivalent, this board provides validated reference design, test-ready layout, and full BOM traceability for rapid prototyping of high-voltage buck controllers in noise-sensitive and thermally constrained systems.

Technical Context

The EV9928-F-00B implements the MP9928GF controller in a fixed 5V output configuration using external 4.7 µH inductor and dual SQJ850EP MOSFETs. It supports cycle-by-cycle current limiting via R7 (0.007 Ω sense resistor), programmable soft-start, and SYNCO clock synchronization for EMI reduction.

Board-level features include power-good (PG) indicator, selectable ILIM threshold, external VCC bias option, and 180° out-of-phase SYNCO output. Input voltage range is verified at 6–60V, with thermal performance validated at 24V_IN/5V_OUT/7A load per test report Rev. 1.01.

Key Specifications

Availability

EV9928-F-00B is available at Aetrix Electronics and suitable for PoE-powered devices, USB charging infrastructure, industrial control power supplies, and linear charger auxiliary rails requiring stable component supply and pre-validated thermal/mechanical design.

Supply support for EV9928-F-00B 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, motor drivers, and LED lighting solutions.

The MP9928 product line delivers high-voltage synchronous buck controllers for industrial, telecom, and automotive power systems where wide VIN range, precise current sensing, and robust fault protection are critical.

FAQ

What input voltage range is validated on the EV9928-F-00B board?

The board is validated for continuous operation from 6 V to 60 V input, with test data confirming stable 5 V/7 A output at 24 V_IN. Operation below 6 V is possible but results in reduced output voltage due to maximum duty cycle limitation.

Can the output voltage be adjusted, and how?

Yes - the output voltage is set by the FB resistor divider (R1 and R4). Replacing R1 (37.4 kΩ) and/or R4 (37.4 kΩ) with values matching the MP9928's 0.8 V feedback reference allows adjustment; recommended design procedure is in MP9928 datasheet Section 8.2.

Does the board support external clock synchronization?

Yes - the SYNCO pin (U1 Pin 15) accepts external clock signals for frequency synchronization. The board includes a 680 pF capacitor (C6) and 51 kΩ resistor (R5) to configure internal oscillator, but these can be removed to enable external clock injection.

What MOSFETs are used, and are they replaceable?

The board uses two Vishay SQJ850EP N-channel MOSFETs (60 V, 24 A, 23 mΩ) in PowerPAK SO-8L package. They are soldered and socketed for replacement; layout supports compatible 8-lead SO-8L or TSDSON packages with matching pinout and thermal pad.

Is the EN/SYNC pin accessible for control?

Yes - EN/SYNC (U1 Pin 6) is brought out to test point JP1 and labeled on silkscreen. Applying >1.3 V enables the controller; <1 V disables it. A pull-up resistor ensures default-enable behavior when unconnected.

What thermal performance is documented for this board?

Test reports (Rev. 1.01) document thermal performance at 24 V_IN/5 V_OUT/7 A with ambient temperature of 25°C. Peak MOSFET case temperature measured ≤85°C; controller junction temperature remains within safe operating limits per MP9928 datasheet specifications.