SP481R Datasheet, PDF (4/9 Pages) Sipex Corporation – High-Fanout RS-485 Transceiver

TEST CIRCUITS
A
R
V_OD
B
R ^VOC
Figure 1. Driver DC Test Load Circuit
Receiver
Output
Test Point
1kΩ
S₁
V_CC
C_RL
1kΩ
S₂
Figure 2. Receiver Timing Test Load Circuit
C_L1
DI
A _RL
B
C_L2
A
RO
B
15pF
Output
Under
Test _CL
500Ω
S₁
V_CC
S₂
Figure 3. Driver/Receiver Timing Test Circuit
Figure 4. Driver Timing Test Load #2 Circuit
SWITCHING WAVEFORMS
+3V
DI
0V
B
DRIVER
OUTPUT _A
DIFFERENTIAL V_O⁺
OUTPUT 0V
V_A – V_B ^VO^–
f = 1MHz; t_R < 10ns; t_F < 10ns
1.5V
1.5V
V_O ^1/2VO
t_PLH
t_PHL
t_DPLH
t_DPHL
t_R
t_PLH
1/2V_O
t_F
t_SKEW = | t_DPLH - t_DPHL |
Figure 5. Driver Propagation Delays
Date: 6/21/04
SP485R RS-485 Serial Transceiver
4
© Copyright 2004 Sipex Corporation