MAX14781E_14 Datasheet, PDF (8/19 Pages) Maxim Integrated Products – Half-Duplex RS-485 Transceiver with Polarity Correction

MAX14781E
Half-Duplex RS-485 Transceiver
with Polarity Correction
Test Circuits and Waveforms (continued)
B
RECEIVER
ATE
VID
OUTPUT
R
A
Figure 6. Receiver Propagation Delay Test Circuit
A
B
t_RPLH
V_OH
VOL ^VCC/2
RO
THE RISE TIME AND FALL TIME OF INPUTS A AND B < 4ns
+1V
-1V
tRPHL
Figure 7. Receiver Propagation Delays
+1.5V
S3
-1.5V
VID
GENERATOR
50Ω
RL
1kΩ
CL
15pF
S1
VCC
S2
S1 OPEN
S2 CLOSED
VS3 = +1.5V
RE
RO
S1 OPEN
S2 CLOSED
VS3 = +1.5V
RE
50%
VCC/2
tRHZ
VCC
0
tRZH, tRZH(SHDN)
VOH
VOH / 2
0
VCC
0
10%
VOH
0.25V
RO
0
S1 CLOSED
S2 OPEN
VS3 = -1.5V
VCC
VCC/2
RE
0
tRZL, tRZL(SHDN)
VCC
(VOL + VCC)/2
RO
VOL
S1 CLOSED
S2 OPEN
VS3 = -1.5V
VCC
50%
VCC/2
RE
0
tRLZ
VCC
RO 10%
0.25V
VOL
Figure 8. Receiver Enable and Disable Times
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