SP485R Datasheet, PDF (4/9 Pages) Exar Corporation – 1/10th Unit Load RS-485 Transceiver

Standard SP485 Reciever
+1.0mA
PIN FUNCTION
Pin 1 - 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
SP485R Reciever
+100µA
-7V
-3V
-0.6mA
+6V
+12V
1 Unit Load
Maximum Input Current
versus voltage.
(Shaded region)
-7V
-3V
-60µA
+6V
+12V
1/10 Unit Load
Maximum Input Current
versus voltage.
(Shaded region)
A
V_OD
B
R
R ^VOC
Figure 2. Driver DC Test Load Circuit
Test Circuits
Receiver
Output
Test Point
1kΩ
S₁
V_CC
C_RL
1kΩ
S₂
Figure 3. Receiver Timing Test Load Circuit
C_L1
DI
A
R_L
B
C_L2
A
RO
B
15pF
Output
500Ω
Under
Test _CL
S₁
V_CC
S₂
Figure 4. RS-485 Driver/Receiver Timing Test
Figure 5. Driver Timing Test Load #2 Circuit
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP485R_100_072309