PM8800A

Overview

The PM8800A is an obsolete integrated Power over Ethernet (PoE) Powered Device (PD) interface and current mode PWM controller by STMicroelectronics. It complies with IEEE 802.3af standards, incorporating detection, classification, under-voltage lockout, and in-rush current limitation. The device features an integrated 100V, 0.5Ω, 800mA hot-swap MOSFET capable of sustaining twice the standard current limit with programmable DC current control up to 800 mA. It supports both isolated and non-isolated configurations via a DC-DC section with programmable oscillator frequency, soft-start, slope compensation, and power good indication.

Feature Summary

• Integrates IEEE 802.3af compliant PD interface with detection and classification logic
• Embeds high-current hot-swap MOSFET for extended power requirements beyond standard limits
• Supports dual power sources from Ethernet LAN cables or local auxiliary supplies
• Includes thermal shutdown protection and programmable soft-start functionality

Applications

• Low power PoE powered devices requiring extended current capacity
• Flyback converter reference designs for 12 V 1 A outputs
• Flyback converter reference designs for 5 V 2 A outputs
• IoT and industrial sensors utilizing PoE infrastructure

Procurement Notes

This component is officially classified as obsolete and has reached end-of-life status. Manufacturers have discontinued production, meaning new units are no longer available through primary distribution channels. Designers must verify availability through secondary market suppliers and assess long-term supply chain risks. Replacement strategies should prioritize compatible next-generation alternatives to ensure project continuity and avoid obsolescence-related disruptions.

Selection Notes

Select this component only for legacy system maintenance or specific historical design reviews where IEEE 802.3af compliance with extended current handling is required. Due to its obsolete status, it is unsuitable for new product development. Engineers should evaluate modern replacements that offer similar integration levels, including integrated hot-swap controllers and PWM regulation, while ensuring compatibility with current supply chain stability and support requirements.

Part Context

The PM8800A belongs to STMicroelectronics' PoE solution portfolio, designed to simplify power supply sections for powered devices. It combines standard PoE interface functions with a switching regulator, targeting applications needing robust power delivery over Ethernet. As part of the PM8800 series, it represents an earlier generation of integrated PoE-PD controllers before the widespread adoption of higher-power standards like 802.3at and 802.3bt.

Replacement Considerations

For active designs, consider the PM8805 for IEEE 802.3bt compliance or the PM8804 PWM controller for flexible DC-DC conversion stages. These newer components offer enhanced power capacities and updated feature sets suitable for modern PoE applications requiring higher efficiency and power density.

FAQ

Does the PM8800A support power sourcing from external AC adapters?

Yes, the integrated switching regulator is designed to operate with power supplied from either Ethernet LAN cables or local auxiliary sources such as AC adapters.

What is the maximum programmable DC current limit for the hot-swap MOSFET?

The PM8800A allows for a programmable DC current limit up to 800 mA, which exceeds the standard IEEE 802.3af current requirements.