PM8801 Datasheet, PDF (1/37 Pages) STMicroelectronics – Programmable classification current

PM8801
High-efficiency, IEEE 802.3at compliant, integrated PoE-PD
interface and PWM controller
Datasheet - production data
HTSSOP24
Features
• IEEE 802.3at compliant PD interface
• Works with power supplied from Ethernet LAN
cables or from local auxiliary sources
• Successful IEEE802.3at Layer1 classification
indicator
• Integrated 100 V, 0.45 Ω, 1 A hot-swap
MOSFET
• Accurate 140 mA typ. inrush current level
• Programmable classification current
• Sleep mode with LED indicator and Maintain
Power Signature (MPS)
• Precise DC current limit set at 640 mA typ.
• Integrated high-voltage startup bias regulator
• Thermal shutdown protection
• Current mode pulse width modulator
• Programmable oscillator frequency
• 80% maximum duty cycle with internal slope
compensation
• Support for flyback, forward, forward active
clamp, flyback with synchronous rectification
Applications
• VoIP phones, WLAN AP
• WiMAX CPEs
• Security cameras
• PoE/PoE+ Powered device appliances
Description
The PM8801 integrates a standard compliant
Power over Ethernet (PoE) interface and a
current mode PWM controller to simplify the
design of the power supply sections of all
powered devices.
The PoE/PoE+ interface incorporates all the
functions required by the IEEE 802.3at including
detection, classification, undervoltage lockout
(UVLO) and inrush current limitation.
The PM8801 specifically performs IEEE802.3at
Layer1 hardware classification, providing an
indication of type 2 PSE successful detection to
the rest of the system.
The PM8801 has been designed to work with
power either from the Ethernet cable connection
or from an external power source such as a wall
adapter, ensuring prevalence of the auxiliary
source with respect to the PoE interface.
The DC/DC section of the PM8801 features a
programmable oscillator frequency, an adjustable
slope compensation, dual complementary low-
side drivers with programmable delay time and
internal temperature sensor.
The PM8801 targets high-efficiency conversion at
all load conditions supporting flyback, forward,
forward active clamp and synchronous
rectification.
Table 1. Device summary
Part number
Package
Packing
PM8801
PM8801TR
HTSSOP24
Tube
Tape and reel
July 2013
This is information on a product in full production.
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