PM8800A
Product Page
The design of power supply sections of all powered
devices can be greatly simplified with the new PM8800, which Integrates
a standard Power over Ethernet (PoE) interface and a current mode
PWM controller.
The PoE interface incorporates all the functions required by the
IEEE 802.3af, including detection, classification, under-voltage
lockout (UVLO) and in-rush current limitation.
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PM8800 specifically targets PDs with extended power
requirements with respect to the limit imposed by the 802.3af standard,
embedding a hot-swap Power MOSFET capable of sustaining twice the
current of the 802.3af standard with a programmable DC current limit.
The integrated switching regulator of the PM8800 is designed to
work with power, either from the Ethernet cable connection or from
an external power source such as an AC adapter. The DC/DC section
of the PM8800 features a programmable oscillator frequency, soft-start,
slope compensation and embeds a voltage output error amplifier allowing
use in both isolated and non isolated configurations.
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| PM800 Features
And Benefits |
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IEEE 802.3af compliant powered device interface
Works with power supplied from ethernet LAN cables or from local
auxiliary sources
Configurable priority of the auxiliary source vs. PoE line
Integrated 100 V, 0. 5 Ω, 800 mA hot-swap MOSFET
Programmable in-rush current limit
Integrated signature resistor
Power good indication
Programmable DC current limit up to 800 mA
High voltage start-up bias regulator
Thermal shutdown protection
Current mode pulse width modulator
Programmable oscillator frequency
Programmable soft-start
80 % maximum duty cycle with programmable slope compensation
Supports both isolated and non-isolated applications
Part
Number
|
Input
voltage range
[V] |
Hot swap
current
[mA] |
Max duty
cycle
[%]
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Package |
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0÷57VDC |
800 |
80 |
HTSSOP16 |
Simplified application schematic
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VoIP phones
WLAN access points
Security cameras
WiMAX CPEs
High power (>12.95 W) powered devices
Numerous Topologies
Supported |
PM8800 works in both isolated and non isolated configuration, supporting
flyback, forward and buck topologies. It can be used in a wide range
of applications, from standard PoE(<15 W) with diode rectification
to higher power (up to 35 W) applications with synchronous rectification.
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