LTC1545IG#TR Linear Technology, LTC1545IG#TR Datasheet - Page 9

• Manufacturer Part Number: LTC1545IG#TR
• Description: IC TXRX SOFTWARE SELECTBL 36SSOP
• Manufacturer: Linear Technology
• Type: Transceiverr

Specifications of LTC1545IG#TR

• Number Of Drivers/receivers: 5/5
• Voltage - Supply: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 36-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Protocol: -

APPLICATIONS
with the termination in the cable head or separate termina-
tions are built on the board and a custom cable routes the
signals to the appropriate termination. Switching the
terminations with FETs is difficult because the FETs must
remain off even though the signal voltage is beyond the
supply voltage for the FET drivers or the power is off.
Using the LTC1344A along with the LTC1543/LTC1545
solves the cable termination switching problem. Via soft-
ware control, the LTC1344A provides termination for the
V.10 (RS423), V.11 (RS422), V.28 (RS232) and V.35
electrical protocols.
V.10 (RS423) Interface
A typical V.10 unbalanced interface is shown in Figure 11.
A V.10 single-ended generator output A with ground C is
connected to a differential receiver with inputs A
nected to A, and input C
ground C. Usually, no cable termination is required for
V.10 interfaces, but the receiver inputs must be compliant
with the impedance curve shown in Figure 12.
U
LTC1543
LTC1545
DCE/DTE
DCE/DTE
'
INFORMATION
(DATA)
(DATA)
D4ENB
U
connected to the signal return
R4EN
M0
M1
M2
M2
M1
M0
14
13
12
11
15
16
11
12
13
14
Figure 10: Single Port DCE V.35 Mode Selection in the Cable
DCE/
DTE
W
22
M2 M1
23
LTC1344A
24
M0 (DATA)
1
U
LATCH
'
con-
21
10k
The V.10 receiver configuration in the LTC1545 is shown
in Figure 13. In V.10 mode switch S3 inside the LTC1545
is turned off. The noninverting input is disconnected
inside the LTC1545 receiver and connected to ground.The
cable termination is then the 30k input impedance to
ground of the LTC1545 V.10 receiver.
V.11 (RS422) Interface
A typical V.11 balanced interface is shown in Figure 14. A
V.11 differential generator with outputs A and B with
ground C is connected to a differential receiver with
ground C
V.11 interface has a differential termination at the receiver
end that has a minimum value of 100 . The termination
resistor is optional in the V.11 specification, but for the
high speed clock and data lines, the termination is required
to prevent reflections from corrupting the data. The
receiver inputs must also be compliant with the imped-
ance curve shown in Figure 12.
CONNECTOR
'
, inputs A
NC
NC
V
CC
'
connected to A, B
1545 F10
CABLE
'
connected to B. The
LTC1545
9