IC PD/OPTO FLYBACK CTRLR 32-DFN

LTC4269CDKD-1#PBF

Manufacturer Part NumberLTC4269CDKD-1#PBF
DescriptionIC PD/OPTO FLYBACK CTRLR 32-DFN
ManufacturerLinear Technology
TypePower Over Ethernet (PoE)
LTC4269CDKD-1#PBF datasheet
 

Specifications of LTC4269CDKD-1#PBF

ApplicationsPower Interface Switch for Power Over Ethernet (PoE) DevicesVoltage - Supply14 V ~ 16 V
Operating Temperature0°C ~ 70°CMounting TypeSurface Mount
Package / Case32-DFNCurrent - Supply1.35mA
InterfaceIEEE 802.3afController TypePowered Device Interface Controller (PD)
Input Voltage60VSupply Current6.4mA
Digital Ic Case StyleDFNNo. Of Pins32
Duty Cycle (%)88%Frequency100kHz
Operating Temperature Range0°C To +70°CMslMSL 1 - Unlimited
Rohs CompliantYesOperating Temperature (max)70C
Operating Temperature (min)0CPin Count32
MountingSurface MountPackage TypeDFN EP
Case Length7mmScreening LevelCommercial
Lead Free Status / RoHS StatusLead free / RoHS Compliant  
1
2
3
4
5
6
7
8
9
10
11
Page 11
12
Page 12
13
Page 13
14
Page 14
15
Page 15
16
Page 16
17
Page 17
18
Page 18
19
Page 19
20
Page 20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Page 12/44

Download datasheet (387Kb)Embed
PrevNext
LTC4269-1
APPLICATIONS INFORMATION
OVERVIEW
Power over Ethernet (PoE) continues to gain popularity
as more products are taking advantage of having DC
power and high speed data available from a single RJ45
connector. As PoE continues to grow in the marketplace,
Powered Device (PD) equipment vendors are running into
the 12.95W power limit established by the IEEE 802.3af
standard.
The IEE802.3at standard establishes a higher power
allocation for Power over Ethernet while maintaining
backwards compatibility with the existing IEEE 802.3af
systems. Power sourcing equipment (PSE) and powered
devices are distinguished as Type 1 complying with the
IEEE 802.3af/IEEE 802.3at power levels, or Type 2 com-
plying with the IEEE 802.3at power levels. The maximum
available power of a Type 2 PD is 25.5W.
The IEEE 802.3at standard also establishes a new method
of acquiring power classifi cation from a PD and communi-
cating the presence of a Type 2 PSE. A Type 2 PSE has the
option of acquiring PD power classifi cation by performing
2-event classifi cation (layer 1) or by communicating with
the PD over the data line (layer 2). In turn, a Type 2 PD
must be able to recognize both layers of communications
and identify a Type 2 PSE.
The LTC4269-1 is specifi cally designed to support the
front end of a PD that must operate under the IEEE 802.3at
standard. In particular, the LTC4269-1 provides the T2P
indicator bit which recognizes 2-event classifi cation.
This indicator bit may be used to alert the LTC4269-1
output load that a Type 2 PSE is present. With an internal
signature resistor, classifi cation circuitry, inrush control,
and thermal shutdown, the LTC4269-1 is a complete PD
Interface solution capable of supporting in the next gen-
eration PD applications.
MODES OF OPERATION
The LTC4269-1 has several modes of operation depend-
ing on the input voltage applied between the V
V
pins. Figure 1 presents an illustration of voltage
PORTN
and current waveforms the LTC4269-1 may encounter with
the various modes of operation summarized in Table 1.
12
50
40
30
20
10
DETECTION V1
50
dV
=
dt
40
30
OFF
20
10
–10
POWER
–20
PWRGD
–30
TRACKS
–40
–50
20
POWER
10
INRUSH
V1 – 2 DIODE DROPS
I
=
1
25kΩ
I
DEPENDENT ON R
CLASS
INRUSH = 100mA
V
PORTP
I
=
LOAD
R
LOAD
I
IN
R
PSE
R
CLASS
and
PORTP
V
Figure 1. V
NEG
Current as a Function of Input Voltage
ON
OFF
CLASSIFICATION
TIME
DETECTION V2
INRUSH
C1
ON
OFF
= R
C1
LOAD
TIME
TIME
POWER
BAD
BAD
POWER
GOOD
PWRGD
TRACKS
V
V
PORTP
PORTP
PWRGD TRACKS
V
PORTN
POWER
POWER
BAD
GOOD
BAD
IN DETECTION
RANGE
TIME
LOAD, I
LOAD
CLASSIFICATION
DETECTION I
TIME
2
DETECTION I
1
V2 – 2 DIODE DROPS
I
=
2
25kΩ
SELECTION
CLASS
LTC4269-1
R
LOAD
V
CLASS
PORTP
PWRGD
C1
PWRGD
V
PORTN
NEG
42691 F01
, PWRGD, PWRGD and PD
42691fb