SP3221E Datasheet, PDF (14/20 Pages) Sipex Corporation – Intelligent +3.0V to +5.5V RS-232 Transceiver

RS-232 Signal
at RECEIVER
INPUT
SHUTDOWN
YES
HIGH
NO
HIGH
NO
HIGH
YES
NO
LOW
LOW
Table 3. AUTO ON-LINE^® Logic
RECEIVER ^+2.7V
RS-232 INPUT ^0V
VOLTAGES -2.7V
STATUS
VCC
0V
+5V
DRIVER
RS-232 OUTPUT _0V
VOLTAGES
-5V
ONLINE
LOW
HIGH
LOW
HIGH/LOW
HIGH/LOW
S
H
U
T
D
O
W
N
tSTSL
tSTSH
tONLINE
Figure 13. AUTO ON-LINE^® Timing Waveforms
STATUS
HIGH
LOW
LOW
HIGH
LOW
Inactive Detection Block
RXINACT
TRANSCEIVER
STATUS
Normal Operation
(AUTO ON-LINE©)
Normal Operation
Shutdown
(AUTO ON-LINE©)
Shutdown
Shutdown
RXIN
RS-232
Receiver Block
RXOUT
Figure 14. Stage I of AUTO ON-LINE^® Circuitry
Delay
Buffer
R ₁ON
SHUTDOWN
Figure 15. Stage II of AUTO ON-LINE^® Circuitry
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • www.exar.com
14
INACTIVE
SP3221E_102_091014