|
|
PDF LT4321IUF Data sheet ( Hoja de datos )
| Número de pieza | LT4321IUF | |
| Descripción | PoE Ideal Diode Bridge Controller | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LT4321IUF (archivo pdf) en la parte inferior de esta página. Total 12 Páginas | ||
|
No Preview Available !
LT4321
PoE Ideal Diode Bridge
Controller
Features
n Reduces Heat, Eliminates Thermal Design Problems
n Maximizes Power Efficiency
n Less than 800µA Quiescent Operating Current
n Fully Compatible with IEEE 802.3 Detection and
Classification
n IEEE 802.3 Compliant When Paired with a Powered
Device (PD) Controller
n Works with 2-Pair and 4-Pair PoE Applications
n Compatible with PoE, PoE+, and LTPoE++™
n 100V Absolute Maximum Voltage
n H-Grade Version Operates Up to 125°C
n 16-Lead 4mm × 4mm QFN Package
Applications
n PoE/PoE+/ LTPoE++ Powered Devices
n DC Polarity Correction and Ideal Diode-ORing of
Telecom Supplies
Description
The LT®4321 is a dual ideal diode bridge controller that
enables a Power over Ethernet (PoE) powered device
(PD) to receive power in either voltage polarity from
RJ-45 data pairs, spare pairs, or both. The LT4321 and
eight N-channel MOSFETs replace the eight diodes in a
passive PoE rectifier bridge. The LT4321 eases thermal
design and increases delivered power.
An internal charge pump allows an all-NMOS bridge
eliminating larger and more costly PMOS switches. The
LT4321 works with 2-pair and 4-pair applications. High
impedance input sense pins prevent reverse current on
unused pairs. If the power source fails or is shorted, a
fast turn-off minimizes reverse current transients. Unlike
discrete ideal bridge solutions, the LT4321 will operate
through transients without enabling the MOSFETs on
unpowered pairs.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath and LTPoE++ are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Typical Application
Powered Device for PoE (to 13W), PoE+ (to 25.5W), or Linear LTPoE++ (to 90W) Systems
1
DATA
PAIRS
2
3
6
4
SPARE
PAIRS
5
7
8
TG12 BG12
IN12
BG36 TG36
OUTP
EN
IN36 LT4321
IN45
EN
IN78 OUTN
BG45 TG45
TG78 BG78
0.1µF
SMAJ60A
+
10µF
VPORT HSGATE HSSRC
LT4275
PWRGD
GND
VIN
ISOLATED
POWER
SUPPLY
RUN
GND
+
–VOUT
4321 TA01
For more information www.linear.com/LT4321
4321f
1
1 page  
LT4321
Pin Functions
IN12: Data Pair Input 1. In a PoE system, IN12 connects
to the center tap of the transformer connected to pins 1
and 2 on an RJ45 connector.
IN36: Data Pair Input 2. In a PoE system, IN36 connects
to the center tap of the transformer connected to pins 3
and 6 on an RJ45 connector.
IN45: Spare Pair Input 1. In a PoE system, IN45 connects
to the center tap of the transformer connected to pins 4
and 5 on an RJ45 connector.
IN78: Spare Pair Input 2. In a PoE system, IN78 connects
to the center tap of the transformer connected to pins 7
and 8 on an RJ45 connector.
TG12: Top-Side Gate Driver Output. TG12 pin pulls high
with respect to IN12 when IN12 is greater than OUTP and
IN36 is less than OUTN.
TG36: Top-Side Gate Driver Output. TG36 pin pulls high
with respect to IN36 when IN36 is greater than OUTP and
IN12 is less than OUTN.
TG45: Top-Side Gate Driver Output. TG45 pin pulls high
with respect to IN45 when IN45 is greater than OUTP and
IN78 is less than OUTN.
TG78: Top-Side Gate Driver Output. TG78 pin pulls high
with respect to IN78 when IN78 is greater than OUTP and
IN45 is less than OUTN.
BG12: Bottom-Side Gate Driver Output. BG12 pin pulls
high with respect to OUTN when IN36 is greater than OUTP
and IN12 is less than OUTN.
BG36: Bottom-Side Gate Driver Output. BG36 pin pulls
high with respect to OUTN when IN12 is greater than OUTP
and IN36 is less than OUTN.
BG45: Bottom-Side Gate Driver Output. BG45 pin pulls
high with respect to OUTN when IN78 is greater than OUTP
and IN45 is less than OUTN.
BG78: Bottom-Side Gate Driver Output. BG78 pin pulls
high with respect to OUTN when IN45 is greater than OUTP
and IN78 is less than OUTN.
EN: Enable, Active Low. Pull down to OUTN to enable ideal
diode bridge mode. EN is internally pulled up to VENOC.
Tie to OUTP if the application circuit uses the EN pin to
enable ideal bridge mode.
EN: Enable, Active High. Pull up to enable ideal diode
bridge mode. EN is internally pulled down to OUTN. Tie
to OUTN if the application circuit uses the EN pin to enable
ideal bridge mode.
OUTP: Positive Output Voltage. OUTP is the rectified
voltage from which the LT4321 draws power.
OUTN: Negative Output Voltage. OUTN is the negative
rectified voltage.
EXPOSED PAD: The exposed pad must be electrically
connected to the OUTN pin.
For more information www.linear.com/LT4321
4321f
5
5 Page 
Package Description
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
UF Package
16-Lead Plastic QFN (4mm × 4mm)
(Reference LTC DWG # 05-08-1692 Rev Ø)
0.72 ±0.05
LT4321
4.35 ±0.05
2.15 ±0.05
2.90 ±0.05 (4 SIDES)
PACKAGE OUTLINE
0.30 ±0.05
0.65 BSC
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
4.00 ±0.10
(4 SIDES)
PIN 1
TOP MARK
(NOTE 6)
0.75 ±0.05
2.15 ±0.10
(4-SIDES)
BOTTOM VIEW—EXPOSED PAD
R = 0.115
TYP
15 16
PIN 1 NOTCH R = 0.20 TYP
OR 0.35 × 45° CHAMFER
0.55 ±0.20
1
2
0.200 REF
0.00 – 0.05
NOTE:
1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGC)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
(UF16) QFN 10-04
0.30 ±0.05
0.65 BSC
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnecFtioornmofoitrseciirncfuoitrsmasadtieosncrwibewdwh.elrineienawr.icllonmot/inLTfr4in3g2e1on existing patent rights.
4321f
11
11 Page | ||
| Páginas | Total 12 Páginas | |
| PDF Descargar | [ Datasheet LT4321IUF.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LT4321IUF | PoE Ideal Diode Bridge Controller | Linear Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |