ltc2871fe Linear Technology Corporation, ltc2871fe Datasheet - Page 15

• Manufacturer Part Number: ltc2871fe
• Description: Ltc2870/ltc2871 - Rs232/rs485 Multiprotocol Transceivers With Integrated Termination
• Manufacturer: Linear Technology Corporation

TEST CIRCUITS
0V OR V
RECEIVER
TE485
DRIVER
INPUT
L
Figure 8. RS485 Termination Resistance and Timing Measurements (Note 5)
A
B
DXEN/DX232
I
A
Figure 9. RS232 Driver Timing and Slew Rate Measurements
+
–
+
–
V
V
AB
B
Figure 10. RS232 Driver Enable and Disable Times
R
R
TERM
L
DRIVER
OUTPUT
R
L
=
C
V
L
I
AB
A
DRIVER
OUTPUT
C
L
DRIVER
DRIVER
TE485
INPUT
INPUT
OUTPUT
OUTPUT
DRIVER
DRIVER
DX232
DXEN/
I
A
SLEW RATE =
½V
L
t
t
½V
ZLD232
ZHD232
½V
t
F
L
3V
OR t
L
6V
–3V
90%
R
t
RTEN485
5V
5V
0V
t
PHLD232
t
F
LTC2870/LTC2871
t
SKEWD232
t
PLHD232
½V
= |t
L
PHLD232
t
½V
t
HZD232
LZD232
t
½V
R
L
L
– t
0V
10%
PLHD232
t
RTZ485
0.5V
0.5V
–3V
3V
|
28701 F08
28701 F09
V
V
V
V
0V
0V
L
L
OHD
OLD
28701 F10
V
V
V
0V
0V
0V
L
OHD
OLD
15
28701f