參數(shù)資料
型號(hào): LTC4259A
廠商: Linear Technology Corporation
英文描述: Quad IEEE 802.3af Power over Ethernet Controller with AC Disconnect
中文描述: 四IEEE 802.3af標(biāo)準(zhǔn)與AC電源斷開(kāi)以太網(wǎng)控制器
文件頁(yè)數(shù): 13/32頁(yè)
文件大?。?/td> 326K
代理商: LTC4259A
LTC4259A
13
4259Af
APPLICATIOU
W
U
U
Figure 11. System Diagram
OVERVIEW
Over the years, twisted-pair Ethernet has become the most
commonly used method for local area networking. The
IEEE 802.3 group, the originator of the Ethernet standard,
has defined an extension to the standard, known as
802.3af, which allows DC power to be delivered simulta-
neously over the same cable used for data communica-
tion. This promises a whole new class of Ethernet devices,
including IP telephones, wireless access points, and PDA
charging stations, which do not require additional AC
wiring or external power transformers, a.k.a. “wall warts.”
With about 13W of power available, small data devices can
be powered by their Ethernet connections, free from AC
wall outlets. Sophisticated detection and power monitor-
ing techniques prevent damage to legacy data-only de-
vices, while still supplying power to newer, Ethernet-
powered devices over the twisted-pair cable.
A device that supplies power is called Power Sourcing
Equipment (PSE); a device that draws power from the
wire is called a Powered Device (PD). A PSE is typically an
Ethernet switch, router, hub, or other network switching
equipment that is commonly found in the wiring closets
where cables converge. PDs can take many forms: digital
IP telephones, wireless network access points, PDA or
notebook computer docking stations, cell phone charg-
ers, and HVAC thermostats are examples of devices that
can draw power from the network.
A PSE is required to provide a nominal 48V DC between
either the signal pairs or the spare pairs (but not both) as
shown in Figure 11. The power is applied as a voltage
between two of the pairs, typically by powering the center-
taps of the isolation transformers used to couple the
differential data signals to the wire. Since Ethernet data is
transformer coupled at both ends and is sent differentially,
a voltage difference between the transmit pairs and the
receive pairs does not affect the data. A 10base-T/
100base-TX Ethernet connection only uses 2 of the 4 pairs
in the cable. The unused or spare pairs can be powered
directly, as shown in Figure 11, without affecting the data.
However, 1000base-T uses all 4 pairs and power must be
connected to the transformer center taps if compatibility
with 1000base-T is required.
REGISTER FU
U
way, the condition causing the LTC4259A to pull the INT
pin down must be removed before the LTC4259A will be
able to pull INT down again. This can be done by reading
and clearing the event registers or by writing a 1 into bit 7
of this register. Setting bit 7 releases the Interrupt pin,
clears all the Event registers and clears all the bits in the
Interrupt register.
4259A F11
SMAJ58A
58V
0.1
μ
F
Tx
Rx
Rx
Tx
SMAJ58A
58V
DATA PAIR
DATA PAIR
V
EE
SENSE GATE OUT
V
DD
INT
SCL
SDAIN
SDAOUT
CMPD3003
10k
1k
0.1
μ
F
100V
0.5
IRFM120A
S1B
SPARE PAIR
SPARE PAIR
1/4
LTC4259A
DGND BYP
AGND
DETECT
I
2
C
3.3V
INTERRUPT
–48V
CAT 5
20
MAX
ROUNDTRIP
0.05
μ
F MAX
RJ45
4
5
4
5
1
2
1
2
3
6
3
6
7
6
7
6
RJ45
1N4002
×
4
1N4002
×
4
PSE
PD
R
CLASS
–48V
IN
PWRGD
–48V
OUT
LTC4257
GND
DC/DC
CONVERTER
5
μ
F
C
IN
300
μ
F
+
V
OUT
GND
0.47
μ
F
100V
X7R
0.1
μ
F
相關(guān)PDF資料
PDF描述
LTC4259ACGW Quad IEEE 802.3af Power over Ethernet Controller with AC Disconnect
LTC4260 Positive High Voltage Hot Swap Controller with I2C Compatible Monitoring
LTC4260CGN Positive High Voltage Hot Swap Controller with I2C Compatible Monitoring
LTC4260CSW Positive High Voltage Hot Swap Controller with I2C Compatible Monitoring
LTC4260CUH Positive High Voltage Hot Swap Controller with I2C Compatible Monitoring
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC4259A-1 制造商:LINER 制造商全稱:Linear Technology 功能描述:Synchronous No-Opto Flyback Controller
LTC4259ACGW 功能描述:IC CTRLR POE QUAD AC DISC 36SSOP RoHS:否 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:2,450 系列:- 控制器類型:SPI 總線至 I²C 總線橋接 接口:I²C,串行,SPI 電源電壓:2.4 V ~ 3.6 V 電流 - 電源:11mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-HVQFN(4x4) 包裝:托盤 配用:568-3511-ND - DEMO BOARD SPI TO I2C 其它名稱:935286452157SC18IS600IBSSC18IS600IBS-ND
LTC4259ACGW#PBF 功能描述:IC CTRLR POE QUAD AC DISC 36SSOP RoHS:是 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:2,450 系列:- 控制器類型:SPI 總線至 I²C 總線橋接 接口:I²C,串行,SPI 電源電壓:2.4 V ~ 3.6 V 電流 - 電源:11mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-HVQFN(4x4) 包裝:托盤 配用:568-3511-ND - DEMO BOARD SPI TO I2C 其它名稱:935286452157SC18IS600IBSSC18IS600IBS-ND
LTC4259ACGW#TR 功能描述:IC CTRLR POE QUAD AC DISC 36SSOP RoHS:否 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:2,450 系列:- 控制器類型:SPI 總線至 I²C 總線橋接 接口:I²C,串行,SPI 電源電壓:2.4 V ~ 3.6 V 電流 - 電源:11mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-HVQFN(4x4) 包裝:托盤 配用:568-3511-ND - DEMO BOARD SPI TO I2C 其它名稱:935286452157SC18IS600IBSSC18IS600IBS-ND
LTC4259ACGW#TRPBF 功能描述:IC CTRLR POE QUAD AC DISC 36SSOP RoHS:是 類別:集成電路 (IC) >> 接口 - 控制器 系列:- 標(biāo)準(zhǔn)包裝:2,450 系列:- 控制器類型:SPI 總線至 I²C 總線橋接 接口:I²C,串行,SPI 電源電壓:2.4 V ~ 3.6 V 電流 - 電源:11mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:24-VFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:24-HVQFN(4x4) 包裝:托盤 配用:568-3511-ND - DEMO BOARD SPI TO I2C 其它名稱:935286452157SC18IS600IBSSC18IS600IBS-ND