SP332 Datasheet, PDF (5/11 Pages) Sipex Corporation – RS-232/RS-485 Multi-Mode Serial Transceiver

A
V_OD
B
R
R ^VOC
Figure 1. RS-485 Driver DC Test Load Circuit
Test Circuits
Receiver
Output
Test Point
1KΩ
S₁
V_CC
C_RL
1KΩ
S₂
Figure 2. Receiver Timing Test Load Circuit
C_L1
DI
A
R_DIFF
B
C_L2
A
RO
B
15pF
Output
500Ω
Under
Test _CL
S₁
V_CC
S₂
Figure 3. RS-485 Driver/Receiver Timing Test Circuit
Figure 4. RS-485 Driver Timing Test Load #2 Circuit
SWITCHING WAVEFORMS
+3V
DRIVER INPUT
0V
B
DRIVER
OUTPUT _A
DIFFERENTIAL ^VO⁺
OUTPUT 0V
V_A –V_B ^VO^–
f ≥1MHz; t_R ≤10ns; t_F ≤10ns
1.5V
t_PLH
t_PHL
V_O ^1/2VO
t_DPLH
t_DPHL
t_R
t _SKEW = |t _DPLH - t_DPHL|
Figure 5. RS-485 Driver Propagation Delays
1.5V
1/2V_O
t_F
V_OD2⁺
A– B
V_OD2^–
V_OH
RECEIVER OUT
V_OL
t_PHL
f = 1MHz; t_R ≤10ns ; t_F ≤ 10ns
0V
INPUT
1.5V
OUTPUT
t_PLH
0V
1.5V
Figure 6. RS-485 Receiver Propagation Delays
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com

SP332_100_012610