Linear Technology LTC4267CDHC, RJ-45 Ethernet Output, Vout = 3.3V @ 1.0A DC804B-A DC804B-A 数据表
产品代码
DC804B-A
LTC4267
1
4267fc
Power over Ethernet
IEEE 802.3af PD Interface with
Integrated Switching Regulator
The LTC
®
4267 combines an IEEE 802.3af compliant Pow-
ered Device (PD) interface with a current mode switching
regulator, providing a complete power solution for PD
applications. The LTC4267 integrates the 25kΩ signature
resistor, classifi cation current source, thermal overload pro-
tection, signature disable and power good signal along with
an undervoltage lockout optimized for use with the IEEE-
required diode bridge. The precision dual level input current
limit allows the LTC4267 to charge large load capacitors
and interface with legacy PoE systems.
regulator, providing a complete power solution for PD
applications. The LTC4267 integrates the 25kΩ signature
resistor, classifi cation current source, thermal overload pro-
tection, signature disable and power good signal along with
an undervoltage lockout optimized for use with the IEEE-
required diode bridge. The precision dual level input current
limit allows the LTC4267 to charge large load capacitors
and interface with legacy PoE systems.
The current mode switching regulator is designed for
driving a 6V rated N-channel MOSFET and features pro-
grammable slope compensation, soft-start, and constant
frequency operation, minimizing noise even with light
loads. The LTC4267 includes an onboard error amplifi er
and voltage reference allowing use in both isolated and
nonisolated confi gurations.
driving a 6V rated N-channel MOSFET and features pro-
grammable slope compensation, soft-start, and constant
frequency operation, minimizing noise even with light
loads. The LTC4267 includes an onboard error amplifi er
and voltage reference allowing use in both isolated and
nonisolated confi gurations.
The LTC4267 is available in space saving, low profi le
16-pin SSOP or DFN packages.
16-pin SSOP or DFN packages.
■
IP Phone Power Management
■
Wireless Access Points
■
Security Cameras
■
Power over Ethernet
■
Complete Power Interface Port for IEEE 802
®
.3af
Powered Device (PD)
■
Onboard 100V, 400mA UVLO Switch
■
Precision Dual Level Inrush Current Limit
■
Integrated Current Mode Switching Regulator
■
Onboard 25kΩ Signature Resistor with Disable
■
Programmable Classifi cation Current (Class 0-4)
■
Thermal Overload Protection
■
Power Good Signal
■
Integrated Error Amplifi er and Voltage Reference
■
Low Profi le 16-Pin SSOP and 3mm × 5mm DFN
Packages
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
Class 2 PD with 3.3V Isolated Power Supply
P
VCC
PWRGD
NGATE
SENSE
I
TH
/RUN
V
FB
PGND
P
OUT
V
PORTP
R
CLASS
SIGDISA
V
PORTN
LTC4267
+
+
R
CLASS
68.1
Ω
1%
5µF
MIN
MIN
10k
470
100k
60.4k
P
VCC
P
VCC
4.7µF
320µF
MIN
22nF
•
•
PA1133
PS2911
BAS516
TLV431
SBM1040
SMAJ58A
3.3V
1.5A
1.5A
CHASSIS
HD01
+
–
+
–
HD01
–48V
FROM
DATA PAIR
–48V
FROM
SPARE PAIR
4267 TA01
Si3440
0.1
Ω
6.8k
10k
0.1µF
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.