- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄69008 > LTC4269CDKD-2 (LINEAR TECHNOLOGY CORP) SWITCHING CONTROLLER, 560 kHz SWITCHING FREQ-MAX, PDSO32 PDF資料下載
參數(shù)資料
| 型號： | LTC4269CDKD-2 |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING CONTROLLER, 560 kHz SWITCHING FREQ-MAX, PDSO32 |
| 封裝： | 7 X 4 MM, PLASTIC, M0-229, DFN-32 |
| 文件頁數(shù)： | 6/34頁 |
| 文件大?。?/td> | 383K |
| 代理商： | LTC4269CDKD-2 |
第1頁第2頁第3頁第4頁第5頁當(dāng)前第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁
LTC4269-2
42692fb
applicaTions inForMaTion
andcurrentwaveformstheLTC4269-2mayencounterwith
the various modes of operation summarized in Table 1.
Table 1. LTC4269-2 Modes of Operation as a Function
of Input Voltage
VPORTP – VPORTN (V) LTC4269-2 MODES OF OPERATION
0V to 1.4V
Inactive (Reset after 1st Classification Event)
1.5V to 9.8V
(5.4V to 9.8V)
25k Signature Resistor Detection Before 1st
Classification Event
(Mark, 11k Signature Corrupt After 1st
Classification Event)
12.5V to On/UVLO
Classification Load Current Active
On/UVLO to 60V
Inrush and Power Applied to PD Load
>71V
Overvoltage Lockout, Classification and Hot Swap
are Disabled.
On/UVLO includes hysteresis. Rising input threshold: 37.2V max.
Falling input threshold: 30.0V min.
These modes satisfy the requirements defined in the
IEEE 802.3af/at specification.
INPUT DIODE BRIDGE
In the IEEE 802.3af/at standard, the modes of operation
reference the input voltage at the PD’s RJ45 connector.
Since the PD must handle power received in either polarity
from either the data or the spare pair, input diode bridges
BR1 and BR2 are connected between the RJ45 connector
and the LTC4269-2 (Figure 2).
The input diode bridge introduces a voltage drop that af-
fectstherangeforeachmodeofoperation.TheLTC4269-2
compensates for these voltage drops so that a PD built
with the LTC4269-2 meets the IEEE 802.3af/at-established
voltage ranges. Note that the Electrical Specifications are
referenced with respect to the LTC4269-2 package pins.
DETECTION
During detection, the PSE looks for a 25k signature resis-
tor which identifies the device as a PD. The PSE will apply
two voltages in the range of 2.8V to 10V and measures
the corresponding currents. Figure 1 shows the detection
voltages V1 and V2 and the corresponding PD current. The
PSE calculates the signature resistance using the
V/I
measurement technique.
The LTC4269-2 presents its precision, temperature-com-
pensated 25k resistor between the VPORTP and VPORTN
pins, alerting the PSE that a PD is present and requests
power to be applied. The LTC4269-2 signature resistor
also compensates for the additional series resistance
introduced by the input diode bridge. Thus a PD built with
the LTC4269-2 conforms to the IEEE 802.3af/at detection
specifications.
SIGNATURE CORRUPT OPTION
In some designs that include an auxiliary power option,
it is necessary to prevent a PD from being detected by a
PSE.TheLTC4269-2signatureresistancecanbecorrupted
with the SHDN pin (Figure 3). Taking the SHDN pin high
will reduce the signature resistor below 11k which is an
invalidsignaturepertheIEEE802.3af/atspecifications,and
alerts the PSE not to apply power. Invoking the SHDN pin
RX–
6
RX+
3
TX–
2
TX+
RJ45
T1
POWERED
DEVICE (PD)
INPUT
42692 F02
1
7
8
5
4
SPARE–
SPARE+
TO PHY
BR2
0.1F
100V
BR1
VPORTP
D3
LTC4269-2
VPORTN
Figure 2. PD Front End Using Diode Bridge on Main and Spare Inputs
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC4269IDKD-2#TR | SWITCHING CONTROLLER, 560 kHz SWITCHING FREQ-MAX, PDSO32 |
| LTC4412IS6#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| LTC4412IS6#TRM | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| LTC4558EUD#TR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC20 |
| LTC4558EUD | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC20 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC4269CDKD-2#PBF | 功能描述:IC PD/SYNC FORWARD CTRLR 32-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型，PCI Express? 內(nèi)部開關(guān):無 電流限制:- 電源電壓:3.3V，12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP（12x12） 包裝:托盤 產(chǎn)品目錄頁面:1423 (CN2011-ZH PDF) |
| LTC4269CDKD-2#TRPBF | 功能描述:IC PD/SYNC FORWARD CTRLR 32-DFN RoHS:是 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:100 系列:- 類型:熱插拔開關(guān) 應(yīng)用:通用 內(nèi)部開關(guān):是 電流限制:可調(diào) 電源電壓:9 V ~ 13.2 V 工作溫度:-40°C ~ 150°C 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-TDFN-EP（3x3） 包裝:管件 |
| LTC4269CDKD-2-PBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:IEEE 802.3at High Power PD and Synchronous Forward Controller with AUX Support |
| LTC4269CDKD-2-TR | 制造商:LINER 制造商全稱:Linear Technology 功能描述:IEEE 802.3at High Power PD and Synchronous Forward Controller with AUX Support |
| LTC4269CDKD-2-TRPBF | 制造商:LINER 制造商全稱:Linear Technology 功能描述:IEEE 802.3at High Power PD and Synchronous Forward Controller with AUX Support |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。