LTC1543CG Linear Technology, LTC1543CG Datasheet - Page 12

• Manufacturer Part Number: LTC1543CG
• Description: IC TXRX SOFTWARE SELECTBL 28SSOP
• Manufacturer: Linear Technology
• Type: Transceiverr

Specifications of LTC1543CG

• Number Of Drivers/receivers: 3/3
• Voltage - Supply: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Protocol: -

LTC1543
APPLICATIO S I FOR ATIO
V.28 (RS232) Interface
A typical V.28 unbalanced interface is shown in Figure 17.
A V.28 single-ended generator output A with ground C is
connected to a single-ended receiver with input A
nected to A, ground C
ground C.
In V.28 mode all switches are off except S3 inside the
LTC1543/LTC1544 which connects a 6k (R8) impedance
to ground in parallel with 20k (R5) plus 10k (R6) for a
combined impedance of 5k as shown in Figure 18. The
noninverting input is disconnected inside the LTC1543/
LTC1544 receiver and connected to a TTL level reference
voltage for a 1.4V receiver trip point.
12
B
C
A
'
'
'
GENERATOR
R1
51.5
R2
51.5
S1
S2
Figure 18. V.28 Receiver Configuration
LTC1344A
Figure 17. Typical V.28 Interface
124
R3
C
A
INTERCONNECTING
U
BALANCED
CABLE
'
A
B
connected via the signal return
U
GND
R8
6k
S3
C
20k
20k
R5
A
R4
TERMINATION
'
'
W
CABLE
R6
10k
R7
10k
LOAD
RECEIVER
U
LTC1543
LTC1544
RECEIVER
'
1543 F17
1543 F18
con-
V.35 Interface
A typical V.35 balanced interface is shown in Figure 19. A
V.35 differential generator with outputs A and B with
ground C is connected to a differential receiver with
ground C
V.35 interface requires a T or delta network termination at
the receiver end and the generator end. The receiver
differential impedance measured at the connector must be
100
nals (A
In V.35 mode, both switches S1 and S2 inside the LTC1344A
are on, connecting the T network impedance as shown in
Figure 20. The switch in the LTC1543 is off. The 30k input
B
C
A
'
'
'
GENERATOR
50
50
'
10 , and the impedance between shorted termi-
R1
51.5
R2
51.5
S1
and B
'
, inputs A
S2
Figure 20. V.35 Receiver Configuration
125
LTC1344A
124
Figure 19. Typical V.35 Interface
'
) and ground C
R3
A
B
C
'
INTERCONNECTING
connected to A, B
BALANCED
CABLE
A
B
GND
R8
6k
S3
'
must be 150
20k
20k
R5
R4
C
B
A
'
'
'
TERMINATION
'
connected to B. The
125
CABLE
R6
10k
R7
10k
LOAD
50
50
RECEIVER
LTC1543
sn1534 1543fas
15 .
RECEIVER
1543 F20
1543 F19