Monolithic Power Systems Inc. MP8001ADS-LF-P

Overview

MP8001ADS-LF-P 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, 810mA current limit (MP8001A variant), open-drain Power Good output, and thermal shutdown at 135°C. It performs detection (26.1kΩ signature), classification (4.42kΩ resistor), and inrush-limited power delivery to downstream DC-DC converters in VoIP phones and security cameras.

For engineers reviewing the MP8001ADS-LF-P datasheet, MP8001ADS-LF-P pinout, MP8001ADS-LF-P application, or MP8001ADS-LF-P equivalent, key selection criteria include its 810mA current limit (vs. 420mA in MP8001), SOIC-8 package with validated 7-pin functional mapping, -40°C to +85°C operating range, and integrated thermal foldback protection for sustained 15W PoE operation.

Technical Context

The MP8001ADS-LF-P implements IEEE 802.3af PD state machine with three distinct operational phases: detection (1.9V–11V window, 26.1kΩ load), classification (10.2V–21.9V window, programmable via RCLASS), and powered operation (≥31V input, current-limited by RILIM). Its internal 100V DMOS switch enables direct connection to PoE midspan or endspan PSE outputs without external high-voltage MOSFETs.

Thermal protection uses a 135°C trip point with 40°C hysteresis and an 8-event counter before latch-off; inrush limiting is achieved via constant-current charging of the input capacitor until the regulated current drops below the programmed ILIMIT threshold (810mA typical for MP8001A). The PG output asserts low after VRTN exceeds 10V and deasserts when VRTN falls below 1.2V, with 75–225μs deglitch timing.

Key Specifications

Pinout & Package

MP8001ADS-LF-P is housed in a standard SOIC-8 package (JEDEC MS-012, variation AA), with 1.27mm pitch, 3.9mm width, and exposed pad not present. Pin 7 is NC (no connect); all other pins are electrically active and validated per MPS Rev. 1.2 datasheet.

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-P delivers 93% higher current limit for 15W operation; versus LT4275IMS#PBF, it reduces component count and layout complexity by integrating the pass device, though sacrifices PoE+ compatibility and programmable retry behavior.

Availability

MP8001ADS-LF-P is available at Aetrix Electronics and suitable for VoIP telephony, security camera systems, and remote wireless access points requiring stable component supply, RoHS-compliant packaging, and long-term industrial lifecycle support.

Supply support for MP8001ADS-LF-P 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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP8001 product line targets IEEE 802.3af PoE Powered Device applications, delivering integrated, thermally robust controllers that eliminate external high-voltage MOSFETs while meeting strict safety and interoperability requirements.

FAQ

What is the maximum input voltage the MP8001ADS-LF-P can withstand?

The MP8001ADS-LF-P supports absolute maximum input voltage of +100V on VDD and RTN pins, with recommended operating input range of 0V to 57V per IEEE 802.3af. Its integrated 100V DMOS pass device enables direct connection to PoE midspan or endspan sources without external clamping components.

How does the MP8001ADS-LF-P implement inrush current limiting?

Inrush limiting is achieved through internal constant-current regulation during capacitor charging: the device delivers a controlled current (330mA typical for MP8001A) until the input capacitor voltage rises sufficiently, then transitions to normal operation. This avoids die overheating and ensures reliable startup even with large input capacitance.

Can the MP8001ADS-LF-P be used in IEEE 802.3at (PoE+) applications?

No. The MP8001ADS-LF-P is certified only for IEEE 802.3af (up to 15.4W at PSE, ~13W at PD). It lacks the 25.5W power handling, dual-signature detection, and extended classification protocols required for 802.3at compliance. Use MPQ8006 or similar for PoE+ designs.

What is the function of the NC pin (Pin 7) on the MP8001ADS-LF-P?

Pin 7 is designated NC (No Connect) and is internally unconnected. It must remain floating-no external circuitry should be attached. This pin may be used for post-package trimming during manufacturing but has no functional role in end-user applications.

How does the thermal shutdown mechanism behave under sustained overload?

Under sustained overload, the MP8001ADS-LF-P first activates thermal foldback-reducing output current progressively above 135°C-then triggers an 8-event counter. After eight consecutive thermal events, it latches off until input voltage is fully removed and reapplied, protecting both the IC and upstream PSE from damage.

Is the Power Good (PG) output actively driven or open-drain?

The PG output is strictly open-drain, requiring an external pull-up resistor (typically 10kΩ to VDD or system rail). It asserts low when RTN voltage exceeds 10V (rising edge) and releases high when RTN falls below 1.2V (falling edge), with 75–225μs deglitch filtering to prevent false triggering.

What classification resistor value is required for IEEE 802.3af Class 3 operation?

A 4.42kΩ resistor between CLASS pin and RTN enables IEEE 802.3af Class 3 (12.95W maximum at PD), verified by the device's guaranteed classification current of 10.6mA at 17.5V VDD. This matches the standard Class 3 signature and is explicitly validated in the MP8001A datasheet.