Monolithic Power Systems Inc. EVQ8623-D-00A

Overview

EVQ8623-D-00A from Monolithic Power Systems is an evaluation board for the MPQ8623GD synchronous step-down converter, delivering 6A continuous output at 1.8V from 8–16V input. It implements constant-on-time (COT) control with adaptive loop response, supports remote enable/disable via ground-referenced EN pin, and features selectable 600/1100/2000kHz switching frequency for PoL power delivery in telecom and server applications.

For engineers reviewing the EVQ8623-D-00A datasheet, EVQ8623-D-00A pinout, EVQ8623-D-00A application, or EVQ8623-D-00A equivalent, this board enables rapid validation of MPQ8623GD performance-including transient response under 1.8V/6A load, soft-start timing (1.5ms programmable), PGOOD signaling, and pre-bias start-up-across input ranges down to 8V and with zero-ESR ceramic output capacitors.

Technical Context

The EVQ8623-D-00A implements a fixed-output 1.8V configuration using the MPQ8623GD QFN-14 (2mm × 3mm) IC, which integrates high- and low-side MOSFETs with 12mΩ/7mΩ R_DS(ON). Its COT architecture eliminates external compensation and achieves ultra-fast load-step response without phase-margin tuning.

Board-level design includes six 47μF X5R 0805 output capacitors, a 1μH SPM5030T inductor, and resistor-based EN biasing (R3/R4) that sets minimum VIN to 8V; lower input operation (down to 2.85V) requires external 3.3V VCC bias or EN overdrive per the quick-start guide.

Key Specifications

Availability

EVQ8623-D-00A is available at Aetrix Electronics and suitable for telecom infrastructure, cloud server PoL development, and high-end GPU power validation requiring stable component supply, repeatable test conditions, and documented reference schematics.

Supply support for EVQ8623-D-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 power management ICs, with design focus on efficiency, integration, and ease of use in power-constrained systems.

The MPQ8623 product line targets high-current, high-density point-of-load conversion in networking, computing, and industrial equipment, emphasizing fast transient response, small solution size, and robust protection features.

FAQ

What input voltage range does the EVQ8623-D-00A support in its default configuration?

The board operates from 8V to 16V input in default configuration due to EN pin biasing via R3/R4 divider. Lower inputs (as low as 2.85V) are possible only when externally supplying 3.3V to VCC or overdriving EN directly - not achievable with VIN alone without hardware modification.

Can the output voltage be adjusted, and if so, how?

Yes, output voltage is adjustable from 0.9V to 6V using external feedback resistors R1/R2. The board ships with fixed 1.8V setting; changing VOUT requires replacing R1/R2 per the MPQ8623GD datasheet's VFB = 0.9V equation and verifying stability with selected inductor and output capacitance.

Does the EVQ8623-D-00A support pre-bias start-up?

Yes, the MPQ8623GD IC on this board supports pre-bias start-up, allowing safe turn-on when the output rail is already biased - critical for hot-swap and multi-rail sequencing applications where downstream circuitry may retain residual voltage.

How is switching frequency selected on this evaluation board?

Switching frequency (600kHz, 1100kHz, or 2000kHz) is selected via jumper JP1, which configures internal oscillator settings. Each position also determines light-load mode: pulse-skip or forced continuous conduction mode (CCM), affecting audible noise and light-load efficiency trade-offs.

What protection features are implemented on the EVQ8623-D-00A?

The board inherits MPQ8623GD's integrated protections: cycle-by-cycle overcurrent (OCP), output overvoltage (OVP), undervoltage lockout (UVLO), input under-voltage (UVP), and thermal shutdown. All trigger latch-off behavior requiring power cycle or EN toggle to recover.

Is the PGOOD signal active-high or active-low?

PGOOD is active-low, open-drain, and clamped low during power failure - providing fail-safe indication to host controllers. External pull-up is required; the board includes a 10kΩ pull-up to 3.3V on the PGOOD net per standard implementation.

What is the physical size and layer count of the EVQ8623-D-00A PCB?

The board measures 81mm × 78mm and uses a 4-layer PCB stack-up (top signal, inner layer 1, inner layer 2, bottom signal), with dedicated power planes and thermal vias under the MPQ8623GD QFN package to support 6A continuous operation at elevated ambient temperatures.