Monolithic Power Systems Inc. MP8001DS-LF-Z

Overview

MP8001DS-LF-Z from Monolithic Power Systems is an IEEE 802.3af-compliant Powered Device (PD) controller for PoE applications, integrating a 100V, 1.2Ω DMOS pass device, 420mA current limit, open-drain Power Good output, and thermal shutdown at 135°C. It performs detection (26.1kΩ), classification (4.42kΩ), and inrush-limited startup for VoIP phones and security cameras.

For engineers reviewing the MP8001DS-LF-Z datasheet, MP8001DS-LF-Z pinout, MP8001DS-LF-Z application, or MP8001DS-LF-Z equivalent, key selection criteria include its 420mA current limit, SOIC-8 package with validated 8-pin terminal mapping, -40°C to +85°C operating range, and compliance with IEEE 802.3af Class 0–3 classification.

Technical Context

The MP8001DS-LF-Z implements a two-stage PD interface: first, a resistive detection stage using a 26.1kΩ pull-down on DET pin to signal presence to the PSE; second, a voltage-based classification stage where CLASS pin voltage determines power class via external resistor (e.g., 4.42kΩ for Class 3). Detection hysteresis is 0.2V, and classification thresholds are 10.2V (on) and 21.9V (off).

Its integrated 100V DMOS switch enables direct connection to PoE input (up to 57V), with foldback current limiting (420mA typ.) and thermal protection that reduces output current above 135°C. Inrush control uses ILIM pin biasing (178kΩ typical) to limit initial charge current to 150mA, preventing die overheating during capacitor charging.

Key Specifications

Pinout & Package

MP8001DS-LF-Z is housed in a standard SOIC-8 package (JEDEC MS-012AA), with exposed pad not present and lead finish RoHS-compliant (Pb-free, halogen-free). Pin 1 is marked by notch or dot; pin 7 is NC (no internal connection, not for routing).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Powered Device controller applications.

Compared with MP8001DS-LF-Z, MP8001ADS-LF-Z delivers higher power capability in identical form factor, while LT4275IMS#PBF adds digital configurability at the cost of increased BOM complexity and voltage margin reduction.

Availability

MP8001DS-LF-Z is available at Aetrix Electronics and suitable for VoIP telephony, security camera systems, and network interface cards requiring stable component supply across industrial temperature ranges (-40°C to +85°C) and long-term PoE infrastructure projects.

Supply support for MP8001DS-LF-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, headquartered in Kirkland, WA, with global design and support centers.

The MP8001 product line targets IEEE 802.3af PoE-powered endpoints, delivering integrated detection, classification, and current-limited power switching in compact SOIC-8 packages for cost-sensitive, space-constrained networking equipment.

FAQ

What is the maximum input voltage rating for MP8001DS-LF-Z?

The absolute maximum input voltage at VDD and RTN pins is +100V, but the recommended operating range is 0V to 57V per IEEE 802.3af specifications. Sustained operation above 57V risks exceeding thermal limits and violates PoE standard compliance, even though the DMOS device withstands higher transient voltages.

Can MP8001DS-LF-Z be used with IEEE 802.3at (PoE+) or 802.3bt (PoE++) systems?

No-MP8001DS-LF-Z is strictly IEEE 802.3af compliant and lacks support for 802.3at's two-event classification or 802.3bt's multi-signature detection. Its 420mA current limit and fixed 26.1kΩ detection signature do not meet higher-power standard requirements, and attempting use may result in PSE rejection or undervoltage lockout.

How does the ILIM pin affect inrush current and current limit settings?

The ILIM pin sets both inrush current (via external resistor) and final current limit threshold. With 178kΩ, inrush is limited to 150mA and final limit remains 420mA. Removing the resistor raises inrush to 420mA and disables foldback, making the part more susceptible to thermal shutdown during large-capacitor charging.

Is Pin 7 (NC) safe to tie to ground or leave floating?

Pin 7 is internally unconnected and must remain unconnected-neither grounded nor routed. Datasheet explicitly states it is "No Connect" and may be used for post-package trim; connecting it risks unintended leakage paths or ESD susceptibility due to lack of internal ESD protection on this terminal.

What is the minimum input capacitance required for stable startup?

A minimum 5µF input capacitor is required to ensure proper inrush timing and UVLO hysteresis behavior. Smaller values cause premature PG assertion or erratic detection; larger values extend charge time proportionally but must stay within thermal limits-exceeding 47µF without adjusting ILIM risks thermal shutdown during startup.

Does MP8001DS-LF-Z support automatic retry after thermal shutdown?

Yes-the device implements an 8-event thermal counter that resets only when VDD drops below 10.8V (within classification range). After eight consecutive overtemperature events, it latches off until power cycle. This prevents repeated cycling under sustained overload while allowing recovery from transient spikes.

How is Power Good (PG) de-glitched, and what is its timing behavior?

PG output includes a 150μs (typ.) deglitch delay on both rising and falling edges to suppress noise-induced false assertions. It remains low until VDD exceeds 10V (rising threshold) and stays asserted only while VDD remains above 9.5V and no thermal fault is active-ensuring clean enable signaling to downstream regulators.