ST485B Datasheet, PDF (4/19 Pages) STMicroelectronics – Low power RS-485/RS-422 transceiver

Truth tables
2
Truth tables
Table 3.
Truth table (driver)
Inputs
RE
DE
DI
X
H
H
X
H
L
X
L
X
Note:
X = Don’t care; Z = High impedance
Table 4.
Truth table (receiver)
Inputs
RE
DE
A-B
L
L
≥ +0.2V
L
L
≤-0.2V
L
L
Inputs open
H
L
X
Note:
X = Don’t care; Z = High impedance
ST485B - ST485C
Outputs
B
A
L
H
H
L
Z
Z
Outputs
RO
H
L
H
Z
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