Monolithic Power Systems Inc. EVQ4456-QT-00A

Overview

EVQ4456-QT-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MPQ4456GQT 1A, 36V input, current-mode synchronous step-down regulator. It delivers a regulated 3.3V output across 8–36V input, operates at 500kHz switching frequency, integrates a 300mΩ MOSFET, and supports programmable frequency up to 4MHz. It is used to validate high-voltage DC/DC conversion in automotive and industrial power systems.

For engineers reviewing the EVQ4456-QT-00A datasheet, EVQ4456-QT-00A pinout, EVQ4456-QT-00A application, or EVQ4456-QT-00A equivalent, this board enables rapid validation of MPQ4456GQT performance-including transient response, efficiency vs. load, UVLO threshold tuning, and output voltage adjustment via external resistor dividers-under real-world input ranges and thermal conditions.

Technical Context

The EVQ4456-QT-00A implements the MPQ4456GQT's current-mode control architecture to deliver fast load-transient response and stable loop behavior without external compensation. Its fixed 3.3V output is set by R6 (165kΩ) and R8 (124kΩ), referencing the IC's 0.8V feedback threshold.

Board-level features include an integrated soft-start function, enable-controlled startup (EN threshold: 1.23V fall / 1.55V rise), and input UVLO preset to ~3.8V using R1 (499kΩ) and R2 (165kΩ). The design uses two parallel 10µH shielded inductors (CLF7045T-100M-H and CLF10040T-100M-H) and a mix of X7R ceramic and electrolytic output capacitors for ripple suppression.

Key Specifications

Availability

EVQ4456-QT-00A is available at Aetrix Electronics and suitable for automotive power subsystem validation, industrial distributed supply design, and high-voltage battery-powered system prototyping requiring stable component supply and repeatable test conditions.

Supply support for EVQ4456-QT-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 MPQ4456 product line targets high-input-voltage, space-constrained applications such as automotive infotainment, industrial sensors, and portable test equipment where wide VIN range and integrated FETs reduce solution size and BOM count.

FAQ

What input voltage range is supported on the EVQ4456-QT-00A?

The board accepts 8V to 36V DC input, matching the MPQ4456GQT's operational range. Input under-voltage lockout is preset to ~3.8V via R1/R2 divider, but can be reconfigured. Operation below 8V is not guaranteed due to board-level component ratings and layout optimization.

Can the output voltage be adjusted, and how?

Yes. VOUT is set by resistive divider R6 and R8, referencing the MPQ4456GQT's 0.8V FB pin. With R6 = 165kΩ and R8 = 124kΩ, output is 3.3V. To change VOUT, recalculate R8 using VOUT = 0.8V × (1 + R6/R8); compensation and inductor values must also be re-evaluated per the MPQ4456 datasheet.

Does the board support programmable switching frequency?

The MPQ4456GQT supports frequency programming up to 4MHz via an external resistor on the RT pin, but the EVQ4456-QT-00A fixes frequency at 500kHz using an internal oscillator configuration. No RT resistor is populated; frequency adjustment requires hardware modification and revalidation.

What thermal performance can be expected at full 1A load?

At VIN = 12V, VOUT = 3.3V, TA = 25°C, the board achieves >88% peak efficiency and maintains junction temperature within safe limits for the MPQ4456GQT QFN3×3 package. Thermal relief is provided via exposed pad soldering and copper pours; no heatsink is required for 1A continuous operation in still air.

Is the EN pin accessible and what logic levels activate the regulator?

Yes. The EN pin is brought out to a 2.0mm golden pin header. Driving EN ≥ 1.55V enables regulation; driving EN ≤ 1.23V disables it. The threshold is internally referenced and stable over temperature. An external pull-up or microcontroller GPIO can directly control startup sequencing.

Are all components on the board populated and tested?

Yes. The EVQ4456-QT-00A is shipped fully assembled and functionally tested per MPS Rev. 1.0 specification. All passive components-including dual 10µH inductors, 22µF electrolytic (C4), and multiple X7R ceramics-are soldered and verified. "NS" (Not Stuffed) parts listed in the BOM are omitted per design intent.