Monolithic Power Systems Inc. EVQ3428A-L-00A

Overview

EVQ3428A-L-00A from Monolithic Power Systems is an evaluation board designed to demonstrate the MPQ3428A synchronous boost converter, delivering 12V/2A output from a 3.3V input with 600kHz fixed-frequency current-mode control, 19A internal switch current limit, and integrated 10mΩ low-side FET in a 3mm×4mm QFN-22 package.

For engineers reviewing the EVQ3428A-L-00A datasheet, EVQ3428A-L-00A pinout, EVQ3428A-L-00A application, or EVQ3428A-L-00A equivalent, this board supports rapid validation of wide-input (3–10V), high-efficiency boost designs for portable power systems requiring precise soft-start, UVLO programming, and thermal shutdown at 150°C.

Technical Context

The EVQ3428A-L-00A implements the MPQ3428A IC in a fully assembled, tested configuration with external 1.5μH inductor, triple 22μF output capacitance, and programmable current sensing via 4.5mΩ sense resistor or internal sensing path. It operates in current-mode control with fixed 600kHz switching frequency and supports input disconnect and output short-circuit protection.

Board-level features include user-accessible test points (VIN, VOUT, EN, GND), adjustable output voltage via R2 (34kΩ default), and configurable soft-start/compensation networks. The layout follows MPS-recommended thermal and EMI practices for QFN-22 devices with exposed thermal pad grounding.

Key Specifications

Availability

EVQ3428A-L-00A is available at Aetrix Electronics and suitable for notebook power delivery, USB-C PD auxiliary rails, and portable audio amplifier biasing requiring stable component supply and fast design iteration.

Supply support for EVQ3428A-L-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, motor drivers, and LED lighting controllers.

The MPQ3428A product line targets high-density, wide-input boost applications in space-constrained portable electronics, emphasizing integration (internal 10mΩ FET, gate driver), flexibility (external/internal current sensing), and robust protection.

FAQ

What input voltage range is supported on the EVQ3428A-L-00A board?

The board is configured for 3V–10V input per design documentation; the underlying MPQ3428A IC supports up to 20V at the IN pin, but board-level components (capacitors, inductor, MOSFETs) are rated for ≤10V operation to ensure reliability and thermal margin.

How is output voltage adjusted on this evaluation board?

VOUT is set to 12V by default using R1=300kΩ and R2=34kΩ in the feedback divider. The formula VOUT = VFB × (1 + R2/R1) applies, where VFB = 1.225V. Replacing R2 allows precise adjustment across the MPQ3428A's supported output range.

Can the board operate with internal current sensing instead of the external resistor?

Yes - by soldering a 0Ω resistor at R8 to connect CLDR to GND, the MPQ3428A automatically selects internal current sensing. This disables the external 4.5mΩ sense path and changes current limit behavior to the 19A internal threshold.

Does the board provide input disconnect functionality?

Yes - when the EN pin is pulled low (<0.4V), the MPQ3428A disables switching and activates input disconnect, isolating VIN from the power path and discharging VOUT to 0V through internal circuitry.

What thermal management provisions exist on the EVQ3428A-L-00A?

The board uses the MPQ3428A's exposed thermal pad (QFN-22 package) soldered to a large copper pour on the bottom layer, with thermal vias connecting to internal ground planes. Thermal shutdown triggers at 150°C, and layout prioritizes low-impedance heat paths for the 1.5μH inductor and dual MOSFETs.

Are test points provided for key signals?

Yes - six golden test points are included: two 1mm (EN, GND) and four 2mm (VIN, VINGND, VOUT, VOGND), enabling non-invasive probing of input/output rails, enable control, and ground references without soldering or fixture modification.