
FIGURE 14. RS-485/422 DRIVER OUTPUT ENABLE/DISABLE TIMES
RL
CL
Tx
Testing B: Tx Input = 0V
Testing A: Tx Input = VCC
Tx Enable
B
A
VOUT
3V
0V
VOH
VOL
Tx Enable
VOUT
VOH + VOL
2
VOH - 0.25V
1.5V
tDZH
tDHZ
RL
CL
Tx
Tx Enable
VCC
B
A
VOUT
Testing B: Tx Input = VCC
Testing A: Tx Input = 0V
3V
0V
VOH
VOL
1.5V
tDZH
tDHZ
Tx Enable
VOUT
VOH + VOL
2
VOL + 0.25V
SP339E
18
RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION
REV. 1.0.3