Monolithic Power Systems Inc. EV8004-QW-00A

Overview

EV8004-QW-00A from Monolithic Power Systems is an IEEE 802.3af-compliant evaluation board for the MP8004GQW-Z PoE Powered Device interface IC with integrated flyback DC-DC converter. It delivers 13W output (12V/1A), supports 36–57V input, features a 275kHz switching frequency, and implements inrush current limiting, OCP, SCP, OTP, and auto-retry protection. It is used to validate PoE-powered VoIP phones and security cameras.

For engineers reviewing the EV8004-QW-00A datasheet, EV8004-QW-00A pinout, EV8004-QW-00A application, or EV8004-QW-00A equivalent, this board enables rapid functional validation of MP8004-based 802.3af PD designs-including startup behavior under 42V+, classification accuracy, flyback regulation stability, and fault recovery timing-without custom PCB development.

Technical Context

The EV8004-QW-00A implements a complete 802.3af Class 3 PD interface with detection, classification, and 100V pass switch control, paired with an isolated flyback converter using the MP8004's internal 150V/0.45Ω power switch. It supports both Ethernet-sourced (via J1 RJ45) and external DC input (VIN/VSS terminals).

Test results confirm stable 12V ±1% regulation at 1A load across 48V–57V input, >85% peak efficiency, and robust short-circuit recovery within 100ms. The board integrates EMI-filtered RJ45 jacks (J1/J2), a Würth WE-LAN transformer (749020011A), and a 12V/1A flyback transformer (Wurth 750311424 or Emei alternative).

Key Specifications

Availability

EV8004-QW-00A is available at Aetrix Electronics and suitable for PoE-powered VoIP telephony, IP security camera deployment, wireless access point prototyping, and small-cell base station development requiring stable component supply and pre-validated reference design fidelity.

Supply support for EV8004-QW-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 analog and mixed-signal semiconductor company specializing in high-performance power management ICs, including DC-DC converters, LED drivers, and PoE solutions.

The EV8004-QW-00A belongs to MPS's PoE evaluation platform family, designed specifically to accelerate time-to-test for IEEE 802.3af-compliant powered devices integrating integrated PD interface + DC-DC conversion.

FAQ

What input sources can power the EV8004-QW-00A?

The board accepts power via standard 802.3af-compliant PSE through RJ45 jack J1, or directly via external DC supply (42–57V) connected to VIN and VSS terminals. Input must exceed 42V to initiate startup; once running, operation continues down to 36V. No auxiliary bias supply is required.

Does the board support IEEE 802.3at (PoE+) or 802.3bt?

No. The EV8004-QW-00A is strictly configured for IEEE 802.3af (Type 1) Class 3 operation, delivering up to 13W. It lacks the higher-voltage detection, signature, and classification circuitry required for 802.3at or 802.3bt compliance.

What transformer options are supported on this board?

The board accommodates two transformer variants: the default Emei core (EE13, 22:9:6 turns ratio, 90µH primary) or the Würth 750311424 (SMD, 4.5:1.5:1 ratio, 100µH primary). Both are pre-layout compatible; no solder modification is needed for either option.

How is output voltage set, and can it be adjusted?

VOUT is fixed at 12V by the onboard ZR431 adjustable shunt regulator (U3) and resistor divider (R17/R18). The feedback network is accessible; changing R17 (9.09kΩ) or R18 (78.7kΩ) allows reprogramming output between ~5V and 24V, subject to MP8004's internal reference and loop stability constraints.

Is isolation verified, and what is the creepage/clearance?

Yes - the board implements reinforced isolation between primary (Ethernet/PSE side) and secondary (12V output) domains per IEC 60950-1. Measured creepage distance exceeds 8mm across the transformer and optocoupler (U2 PC357), with clearance >5mm between high- and low-side traces.

Can the board be used for Class 0–2 PD validation?

Yes. Classification is determined by the MP8004's internal resistor network (R4 = 26.1kΩ, R5 = 357Ω, R6 = 178kΩ), which sets a 12.15kΩ detection signature and 25.5kΩ classification resistance - compliant with Class 3. To test lower classes, replace R4/R5/R6 with values matching IEEE 802.3af Table 33.