LTC1387 Linear Technology, LTC1387 Datasheet - Page 7

• Manufacturer Part Number: LTC1387
• Description: Single 5V RS232/RS485 Multiprotocol Transceiver
• Manufacturer: Linear Technology

BLOCK
Figure 1. RS485 Driver
Test Load
TEST CIRCUITS
V
232 = 0V, DXEN = 3V
Figure 4. RS232 Driver
Timing Test Circuit
DD
Y
485/232
Z
C1
DXEN
D
GND
V
*485/232, DXEN, RXEN = V
OD
A
B
Y
Z
10
1
2
3
4
5
6
7
8
9
WITHOUT LOOPBACK
Y, Z
RS232 MODE
DIAGRAM
R
R
LTC1387 • F01
V
C
OC
L
20
19
18
17
16
15
14
13
12
11
CC
R
LTC1387 • F04
L
R
R
D
D
ON
RXEN
V
V
W
CC
A
B
Y
Z
EE
C2
V
485/232*
DD
C1
DXEN
SLEW
GND
A
B
Y
Z
D
10
1
2
3
4
5
6
7
8
9
WITHOUT LOOPBACK
Figure 2. RS485 Driver/Receiver
Timing Test Circuit
RS485 MODE
Y
Z
485 = 3V, DXEN = 3V, RXEN = 3V
D
Figure 5. RS232 Receiver
Timing Test Circuit
232 = 0V, DXEN = 3V, RXEN = 3V
R
L
Y, Z
20
19
18
17
16
15
14
13
12
11
V
R
R
D
SLEW
ON
RXEN
V
CC
A
B
Y
EE
A, B
C2
C
C
485/232
C1
L
L
DXEN*
V
GND
DD
Y
Z
A
B
R
10
1
2
3
6
7
8
9
WITH LOOPBACK
R
RS232 MODE
LTC1387 • F05
15pF
LTC1387 • F02
15pF
20
19
18
17
16
15
14
13
12
11
V
R
R
D
D
RXEN*
V
CC
A
B
Y
Z
ON
EE
C2
485/232*
Figure 3. RS485 Driver Output
Enable/Disable Timing Test Load
Figure 6. Receiver Output
Enable/Disable Timing Test Load
C1
DXEN*
RECEIVER
V
GND
DD
DR OUT
Y
Z
OUT
10
1
2
3
6
7
8
9
WITH LOOPBACK
RS485 MODE
C
LTC1387
C
500
L
L
1k
LTC1387 • F06
LTC1387 • F03
V
V
CC
CC
S1
LTC1387 • BD
S1
S2
S2
20
19
18
17
16
15
14
13
12
11
V
R
R
D
SLEW
RXEN*
V
CC
A
B
Y
7
EE
ON
C2