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PM8800AのメーカーはSTMicroelectronicsです、この部品の機能は「Integrated IEEE 802.3af compliant PoE-PD interface and PWM controller」です。 |
部品番号 | PM8800A |
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部品説明 | Integrated IEEE 802.3af compliant PoE-PD interface and PWM controller | ||
メーカ | STMicroelectronics | ||
ロゴ | |||
このページの下部にプレビューとPM8800Aダウンロード(pdfファイル)リンクがあります。 Total 30 pages
PM8800A
Integrated IEEE 802.3af compliant PoE-PD interface
and PWM controller with support of external source
Features
■ IEEE 802.3af compliant PD interface
■ Works with power supplied from Ethernet LAN
cables or from local auxiliary sources
■ Integrated 100 V, 0.5 Ω, 800 mA hot-swap
MOSFET
■ Integrated signature resistor
■ Programmable in-rush current limit
■ Programmable classification current
■ 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
■ Power good indication
■ 80 % maximum duty cycle with internal slope
compensation
■ Supports both isolated and non-isolated
Applications.
■ HTSSOP16 package
Applications
■ VoIP phones, WLAN access points
■ Security cameras
■ PoE powered device appliances
■ High power (>12.95 W) powered devices
HTSSOP16
Description
The PM8800A integrates a standard 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 interface incorporates all the functions
required by the IEEE 802.3af including detection,
classification, under-voltage lockout (UVLO) and
in-rush current limitation.
PM8800A specifically targets PD with extended
power requirement with respect to the limit
imposed by the 802.3af standard, embedding a
hot-swap MOSFET capable of sustaining twice
the current of the 802.3af standard with a
programmable DC current limit.
The integrated switching regulator has been
designed to work with power either form the
Ethernet cable connection or from an external
power source such as AC adapter.
The DC-DC section of the PM8800A features a
programmable oscillator frequency, soft-start,
slope compensation and embeds a voltage output
error amplifier allowing use in both isolated and
non isolated configuration.
Table 1. Device summary
Order codes
PM8800A
PM8800ATR
Package
HTSSOP16
HTSSOP16
Packing
Tube
Tape and reel
February 2008
Rev 2
1/35
www.st.com
35
1 Page PM8800A
Contents
7 Auxiliary sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
8.1 HTSSOP16 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3/35
3Pages Pins description and connection diagrams
2 Pins description and connection diagrams
PM8800A
2.1
Figure 5. Pins connection (top view)
RT
SS
AUXII
VIN
RCLASS
AUXI_IRL
DCCL
VSS
1 16
2 15
3 14
4 13
5 12
6 11
7 10
89
HTSSOP-16
AGND
VFB
COMP
CS
nPGD
VCC
GD
GND
Pin descriptions
Table 2. Pin description
Pin# Name
Function
Oscillator timing resistor pin and synchronization input.
1 RT An external resistor connected from RT to AGND sets the oscillator frequency.
This pin will also accept narrow ac-coupled synchronization pulses from an
external clock.
Soft-start input.
2 SS An external capacitor connected from SS and AGND and an internal
10 µA current source set the soft-start ramp rate. this pin is also used to set the
hiccup timer in case of overcurrent conditions. See Section 6 for detail.
Auxiliary source enable pin.
3 AUXII Use this pin to power up the DC/DC section only from the external source. The
auxiliary source can prevail over the PoE source depending on the value of the
resistor between this pin and the external source. See Section 7 for detail.
System high potential input.
4 VIN The diode “OR” of PoE line and auxiliary sources connected to the PD, it is the
most positive input potential.
Classification resistor pin.
5 RCLASS
Connect a classification programming resistor between this pin and VSS.
In-rush current limit and auxiliary source enable pin.
Pulling up this pin to the auxiliary source will change the internal UVLO settings
6 AUXI_IRL and allow PD to be powered with voltage lower than nominal PoE voltages. In this
condition inrush current limit is set to default values. See Section 7 for details.
A resistance between this pin and VSS will set the level of inrush current limit.
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ページ | 合計 : 30 ページ | ||
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部品番号 | 部品説明 | メーカ |
PM8800 | Integrated IEEE 802.3af compliant PoE-PD interface and PWM controller | STMicroelectronics |
PM8800A | Integrated IEEE 802.3af compliant PoE-PD interface and PWM controller | STMicroelectronics |