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参数资料
| 型号： | LTC4270AIUKG#PBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 模拟信号调理 |
| 英文描述： | SPECIALTY ANALOG CIRCUIT, PQCC52 |
| 封装： | 8 X 7 MM, LEAD FREE, PLASTIC, QFN-52 |
| 文件页数： | 9/32页 |
| 文件大小： | 344K |
| 代理商： | LTC4270AIUKG#PBF |
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LTC4270/LTC4271
17
42701fa
Extended Power LTPoE++
A-grade LTC4270/LTC4271 parts add the capability to
autonomously deliver up to 90W of power to the PD.
LTPoE++ PDs may forgoe 802.3 LLDP support and rely
solely on the LTPoE++ Physical Classification to negotiate
power with LTPoE++ PSEs; this greatly simplifies high-
power PD implementations.
LTPoE++ may be optionally enabled for A-grade LTC4270/
LTC4271s by setting both the High Power Enable and
LTPoE++ Enable bits.
The higher levels of LTPoE++ delivery impose additional
layout and component selection constraints. LTC4270 pin
selects allow the AUTO pin mode LTC4271 to autonomously
power up to supported power levels. If the AUTO pin is
high, the XIO1 and XIO0 pins are sampled at reset to de-
termine the maximum deliverable power. PDs requesting
more than the available power limits are not powered.
Table 1. LTPoE++ AUTO Pin Mode Maximum Delivered Power
Capabilities
POWER
XIO1
XIO0
35W
0
45W
0
1
70W
1
0
90W
1
BACKWARDS COMPATIBILITY
The LTC4270/LTC4271 chipset is designed to be backward
compatible with the LTC4266, operating in Type 2 mode,
without software changes; only minor layout changes
are required to implement a fully compliant IEEE 802.3at
design.
Some LTC4266 registers have been obsoleted in the
LTC4270/LTC4271 chipset. The obsoleted registers are not
required for 802.3at compliant PSE operation. For more
details about software differences between the LTC4266
and LTC4270/LTC4271, refer to the LTC4271 Software
Programming document.
Operation with high power mode disabled is obsoleted in
the LTC4270/LTC4271 chipset. All operations previously
available in low power mode are fully implemented as a
subset of the high power mode capabilities.
APPLICATIONS INFORMATION
OPERATING MODES
The LTC4270/LTC4271 includes 12 independent ports,
each of which can operate in one of four modes: manual,
semi-auto, AUTO pin, or shutdown.
Table 2. Operating Modes
MODE
AUTO
PIN
OPMD DETECT/
CLASS
POWER-UP
AUTOMATIC
ICUT/ILIM
ASSIGNMENT
AUTO Pin
1
11b
Enabled
at Reset
Automatically
Yes
Reserved
0
11b
N/A
Semi-auto
0
10b
Host
Enabled
Upon
Request
No
Manual
0
01b
Once
Upon
Request
Upon
Request
No
Shutdown
0
00b
Disabled
No
In manual mode, the port waits for instructions from the
host system before taking any action. It runs a single
detection or classification cycle when commanded to by
the host, and reports the result in its Port Status register.
The host system can command the port to turn on or off
the power at any time.
In semi-auto mode, the port repeatedly attempts to detect
and classify any PD attached to it. It reports the status of
these attempts back to the host, and waits for a command
from the host before turning on power to the port. The
host must enable detection (and optionally classification)
for the port before detection will start.
AUTO pin mode operates the same as semi-auto mode
except it will automatically turn on the power to the port if
detection is successful. AUTO pin mode will autonomously
set the ICUT and ILIM values based on the class result. This
operational mode is only valid if the AUTO pin is high.
In shutdown mode, the port is disabled and will not detect
or power a PD.
Regardless of which mode it is in, the LTC4270/LTC4271
will remove power automatically from any port that gener-
ates a current limit fault. It will also automatically remove
power from any port that generates a disconnect event if
disconnect detection is enabled. The host controller may
also command the port to remove power at any time.
相关PDF资料 |
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| LTC4274CIUHF#PBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
| LTC4274AIUHF-4#TRPBF | POWER SUPPLY MANAGEMENT CKT, PQCC38 |
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4270BIUKG#PBF | 制造商:Linear Technology 功能描述:POE Controller 25.5W 52-Pin QFN EP 制造商:Linear Technology 功能描述:Bulk 制造商:Linear Technology 功能描述:IC POE LTPOE 12-PORT PSE 52-QFN 制造商:Linear Technology 功能描述:IC PSE CONTROLLER 3.3V QFN-52 制造商:Linear Technology 功能描述:PSE CNTRL 12 PORT 25.5W 1M 制造商:Linear Technology 功能描述:IC, PSE CONTROLLER, 3.3V, QFN-52; Input Voltage:3.3V; Supply Current:10mA; UVLO:25V; Digital IC Case Style:QFN; No. of Pins:52; Frequency:1MHz; Operating Temperature Min:-40C; Operating Temperature Max:85C; Package / Case:52-QFN ;RoHS Compliant: Yes |
| LTC4270BIUKG#PBF | 制造商:Linear Technology 功能描述:IC, PSE CONTROLLER, 3.3V, QFN-52 |
| LTC4270BIUKG#TRPBF | 制造商:Linear Technology 功能描述:POE Controller 25.5W 52-Pin QFN EP 制造商:Linear Technology 功能描述:PSE CONTROLLER, 12PORT, 57V, QFN-52; Supply Current:10mA; UVLO:25V; Digital IC Case Style:QFN; No. of Pins:52; Duty Cycle (%):6.3%; Frequency:1MHz; Operating Temperature Min:-40C; Operating Temperature Max:85C ;RoHS Compliant: Yes |
| LTC4270CIUKG#PBF | 制造商:Linear Technology 功能描述:POE Controller 13W 52-Pin QFN EP 制造商:Linear Technology 功能描述:IC POE LTPOE 12-PORT PSE 52-QFN 制造商:Linear Technology 功能描述:PSE CNTRL 12 PORT 13W 1MHZ 制造商:Linear Technology 功能描述:IC PSE CONTROLLER 3.3V QFN-52 制造商:Linear Technology 功能描述:IC, PSE CONTROLLER, 3.3V, QFN-52; Input Voltage:3.3V; Supply Current:10mA; UVLO:25V; Digital IC Case Style:QFN; No. of Pins:52; Frequency:1MHz; Operating Temperature Min:-40C; Operating Temperature Max:85C; Package / Case:52-QFN ;RoHS Compliant: Yes |
| LTC4270CIUKG#PBF | 制造商:Linear Technology 功能描述:IC PSE CONTROLLER 3.3V QFN-52 制造商:Linear Technology 功能描述:IC, PSE CONTROLLER, 3.3V, QFN-52 |
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