Monolithic Power Systems Inc. MP8004GQW-Z

Overview

MP8004GQW-Z from Monolithic Power Systems is an IEEE 802.3af-compliant Powered Device (PD) interface IC with integrated flyback DC/DC converter, delivering up to 13W PoE power. It integrates a 100V/1Ω PD pass switch, 150V/0.45Ω internal power switch, and supports detection, classification, inrush current limiting, and full protection (OCP, SCP, OTP, UVLO/OVLO). It is used in VoIP phones and security cameras where single-chip PoE-PD front-end integration reduces BOM count and board space.

For engineers reviewing the MP8004GQW-Z datasheet, MP8004GQW-Z pinout, MP8004GQW-Z application, or MP8004GQW-Z equivalent, this page provides verified technical context, exact pin functions, real-world application roles, and validated alternative options for PoE-PD system design and sourcing.

Technical Context

The MP8004GQW-Z implements dual-stage PoE power management: a PD interface stage with programmable detection (26.1kΩ), classification (4.42kΩ for Class 0), and 420mA input current limit; followed by a flyback DC/DC controller with 150V internal MOSFET, cycle-by-cycle current limiting (4A), and programmable switching frequency (55–550 kHz via RT pin).

It features isolated/non-isolated flyback topology support, internal soft-start, auto-retry hiccup mode under short-circuit, zero-load regulation via cycle skipping, and independent thermal monitoring for both PD pass device (latching shutdown) and DC/DC switch (auto-recovery). The LINE pin enables remote enable/disable and line feed-forward duty-cycle limiting (DMAX = 67.5% at VLINE = 1.3V, decreasing as VLINE rises).

Key Specifications

Pinout & Package

MP8004GQW-Z is housed in a thermally enhanced 4mm × 6mm QFN-20 package with exposed thermal pad connected to GND (pins 1, 2). The package supports high-power dissipation (θJA = 36°C/W) and requires PCB copper area under the exposed pad for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PoE-PD interface with integrated DC/DC converter applications.

Compared with LT4275AIMSE#PBF and TPS23753APWR, MP8004GQW-Z delivers true single-chip integration-eliminating external MOSFETs, controllers, and discrete current-limit resistors-making it optimal for cost-sensitive, space-constrained 13W PoE-PD endpoints where time-to-market and qualification effort are critical.

Availability

MP8004GQW-Z is available at Aetrix Electronics and suitable for VoIP telephony, IP surveillance, wireless access points, and small-cell base station designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MP8004GQW-Z 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, PoE, motor drivers, and LED lighting.

The MP8004 product line targets IEEE 802.3af PoE-PD applications demanding high integration, thermal robustness, and minimal external components-designed specifically for endpoint devices where board space, reliability, and time-to-market are decisive factors.

FAQ

What is the maximum input voltage rating for the MP8004GQW-Z PD interface?

The MP8004GQW-Z PD interface supports up to 57V continuous input (VDD), with absolute maximum rating of 100V on VDD, VIN, and RTN pins. This accommodates the full IEEE 802.3af PoE voltage range (37–57V) plus margin for transients and cable drop.

How does the MP8004GQW-Z implement inrush current limiting during PD startup?

It uses an external resistor (RILIM) on the ILIM pin to set a constant-current charge for the downstream DC/DC input capacitor. With RILIM = 178kΩ, inrush is limited to 150mA typical, preventing thermal stress on the internal 100V pass switch and avoiding premature shutdown during capacitor charging.

Can the MP8004GQW-Z be synchronized to an external clock signal?

Yes-the RT pin accepts an external clock pulse (50–150ns width, >3.5V peak) for synchronization. The external clock frequency must exceed the internal oscillator's programmed frequency, enabling precise timing alignment in multi-rail or noise-sensitive systems.

What protection mechanisms prevent damage during output short-circuit conditions?

Under short-circuit, the MP8004GQW-Z enters hiccup mode: after 15 VCC ramp cycles between 4.5V and 5.85V, it initiates soft-start again. Cycle-by-cycle current limiting (4A threshold) and automatic shutdown reduce average input current, minimizing thermal stress on both PD pass switch and DC/DC MOSFET.

Is the MP8004GQW-Z compatible with IEEE 802.3at (PoE+) or 802.3bt (PoE++) standards?

No-it is strictly IEEE 802.3af (Class 0–3, ≤13W) compliant. It lacks the higher-power detection signatures, multi-event classification, and 2-pair negotiation required for 802.3at/bt. For PoE+ or PoE++, consider MPS's MP8018 or MPQ8018 series.

What is the role of the LINE pin beyond UV/OV detection?

Beyond line monitoring, the LINE pin enables feed-forward duty-cycle limiting: as VLINE increases from 1.3V, DMAX decreases linearly (e.g., to 42% at 3V), protecting the transformer from saturation and improving transient response under high-line conditions.

Does the MP8004GQW-Z require an external bootstrap capacitor for the internal power switch?

No-the 150V internal MOSFET is a low-side N-channel switch in flyback configuration; it does not require bootstrap biasing. Gate drive is fully integrated and self-contained, eliminating external bootstrap components.