20
LTC2847
sn2847 2847fs
LT/TP 0603 1K PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2003
RELATED PARTS
PART NUMBER
LTC1321
LTC1334
LTC1343
LTC1344A
LTC1345
LTC1346A
LTC1543
DESCRIPTION
Dual RS232/RS485 Transceiver
Single 5V RS232/RS485 Multiprotocol Transceiver
Software-Selectable Multiprotocol Transceiver
Software-Selectable Cable Terminator
Single Supply V.35 Transceiver
Dual Supply V.35 Transceiver
Software-Selectable Multiprotocol Transceiver
COMMENTS
Two RS232 Driver/Receiver Pairs or Two RS485 Driver/Receiver Pairs
Two RS232 Driver/Receiver or Four RS232 Driver/Receiver Pairs
4-Driver/4-Receiver for Data and Clock Signals
Perfect for Terminating the LTC1543 (Not Needed with LTC1546)
3-Driver/3-Receiver for Data and Clock Signals
3-Driver/3-Receiver for Data and Clock Signals
Terminated with LTC1344A for Data and Clock Signals, Companion to
LTC1544 or LTC1545 for Control Signals
Companion to LTC1546 or LTC1543 for Control Signals Including LL
5-Driver/5-Receiver Companion to LTC1546 or LTC1543
for Control Signals Including LL, TM and RL
3-Driver/3-Receiver with Termination for Data and Clock Signals
Companion to LTC2846 for Control Signals Including LL
5-Driver/5-Receiver Companion to LTC2846 or LTC2847 for Control
Signals Including LL, TM and RL
3.3V Supply, 3-Driver/3-Receiver with Termination for Data and Clock
Signals, Generates the Required 5V and
±
8V Supplies for LTC2846
Companion Parts
LTC1544
LTC1545
Software-Selectable Multiprotocol Transceiver
Software-Selectable Multiprotocol Transceiver
LTC1546
LTC2844
LTC2845
Software-Selectable Multiprotocol Transceiver
3.3V Software-Selectable Multiprotocol Transceiver
3.3V Software-Selectable Multiprotocol Transceiver
LTC2846
3.3V Software-Selectable Multiprotocol Transceiver
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
G
FAX: (408) 434-0507
G
www.linear.com
The V.11 drivers are driven between V
CC
and GND while
the V.10 drivers are driven between V
CC
and V
EE
. Assume
that the V.11 driver outputs are high and V.10 driver
outputs low. Current going into each 100
V.11 receiver
termination = (110mA – 2.7mA) – 23mA/3 = 28.1mA.
Current going into each 450
V.10 receiver termination =
23mA – 2mA/2 = 10.5mA. From Equation (2), V.11 P
RT
=
79mW and V.10 P
RT
= 49.6mW.
From Equation (3), P
DISS(2845)
= 5V (110mA – 23mA) +
(8V 0.3mA) + 5.5V 23mA – 3 79mW – 2 49.6mW =
TYPICAL APPLICATIO S
228mW. Since the LTC2845 runs slow control signals, the
AC power dissipation can be assumed to be equal to the DC
power dissipation.
The extra power dissipated in the LTC2847 due to LTC2845
is given by Equation(4), P
DISS1(2847)
= 25% (8V 0.3mA)
+ 43% (5.5V 23mA) = 55mW. So for an X.21 DCE port
running at 10MBd, the LTC2847 dissipates approximately
718mW + 55mW = 773mW while the LTC2845 dissipates
228mW.