PIN FUNCTION
Pin ꢀ - RO - Receiver Output
Pin 2 - RE - Receiver Output Enable Active LOW
Pin 3 - DE - Driver Output Enable Active HIGH
Pin 4 DI - Driver Input
Pin 5 - GND - Ground Connection
Pin 6 - A - Driver Output / Receiver input
Non-Inverting
Pin 7 - B - Driver Output / Receiver Input Inverting
Pin 8 - Vcc - Positive Supply 4.75V ≤ Vcc ≤ 5.25V
RECEIVER INPUT GRAPH
Standard SP485 Reciever
+1.0mA
SP485R Reciever
+100µA
-7V
-7V
-3V
-3V
+12V
+12V
+6V
+6V
-0.6mA
-60µA
1 Unit Load
1/10 Unit Load
Maximum Input Current
versus voltage.
(Shaded region)
Maximum Input Current
versus voltage.
(Shaded region)
TEST CIRCUITS
1kΩ
A
Test Point
1kΩ
Receiver
Output
V
CC
R
R
S
1
V
OD
C
RL
V
OC
S
2
B
Figure 2. Driver DC Test Load Circuit
Figure 3. Receiver Timing Test Load Circuit
V
CC
CL1
S
1
A
A
500Ω
DI
RL
Output
Under
Test
RO
B
B
CL2
15pF
C
L
S
2
Figure 4. RS-485 Driver/Receiver Timing Test
Figure 5. Driver Timing Test Load #2 Circuit
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 5ꢀ0-668-70ꢀ7 • www.exar.com
SP485R_ꢀ00_072309
4
EXAR [ EXAR CORPORATION ]
