SP310ACT SIPEX [Sipex Corporation], SP310ACT Datasheet - Page 6

• Manufacturer Part Number: SP310ACT
• Description: Enhanced RS-232 Line Drivers/Receivers
• Manufacturer: SIPEX [Sipex Corporation]

Figure 4. Typical Circuits using the SP233ACP and SP233ACT
Shutdown (SD) and Enable (EN)
SP310A/SP312A Only
Both the SP310A and SP312A have a shut-down/
standby mode to conserve power in battery-pow-
ered systems. To activate the shutdown mode,
which stops the operation of the charge pump, a
logic “0” is applied to the appropriate control line.
For the SP310A, this control line is ON/OFF (pin
18). Activating the shutdown mode also puts the
SP310A transmitter and receiver outputs in a high
impedance condition (tri-stated). The shutdown
mode is controlled on the SP312A by a logic “0”
on the SHUTDOWN control line (pin 18); this also
puts the transmitter outputs in a tri–state mode.
The receiver outputs can be tri–stated separately
during normal operation or shutdown by a logic
“1” on the ENABLE line (pin 1).
Wake–Up Feature (SP312A Only)
The SP312A has a wake–up feature that keeps
all the receivers in an enabled state when the
device is in the shutdown mode. Table 1 defines
the truth table for the wake–up function.
With only the receivers activated, the SP312A
typically draws less than 5 A supply current
(10 A maximum). In the case of a modem
interfaced to a computer in power down mode,
the Ring Indicator (RI) signal from the modem
would be used to "wake up" the computer,
allowing it to accept data transmission.
SP231ADS/01
connection to
Do not make
+10V Power
-10V Power
these pins
R OUT
R OUT
1
2
Internal
Internal
T IN
T IN
Supply
Supply
1
2
20
13
12
17
14
2
1
3
8 C +
C -
V-
V-
V+
1
1
400k
400k
GND
+5V INPUT
6
R
SP233A
R
1
2
V
CC
7
GND
T
T
1
2
5k
5k
9
C +
C +
C -
C -
2
2
2
2
11
15
10
16
18
19
5
4
R IN
R IN
T OUT
T OUT
SP231A Enhanced RS-232 Line Drivers/Receivers
1
2
1
2
6
Table 1. Wake-up Function Truth Table.
After the ring indicator signal has propagated
through the SP312A receiver, it can be used to
trigger the power management circuitry of the
computer to power up the microprocessor, and
bring the SD pin of the SP312A to a logic high,
taking it out of the shutdown mode. The receiver
propagation delay is typically 1 s. The enable
time for V
V
be sent back to the modem on the data terminal
ready (DTR) pin signifying that the computer is
ready to accept and transmit data.
Pin Strapping — SP233ACT Only
The SP233A packaged in the 20–pin SOIC
package (SP233ACT) has a slightly different
pinout than the SP233A in other package
configurations. To operate properly, the following
pairs of pins must be externally wired together:
All other connections, features, functions and
performance are identical to the SP233A as
specified elsewhere in this data sheet.
–
SD
have settled to their final values, a signal can
0
0
1
1
connection to
Do not make
the two V– pins (pins 10 and 17)
the two C
the two C
+10V Power
-10V Power
EN
these pins
+
R OUT
R OUT
0
1
0
1
1
2
Internal
Internal
and V
T IN
T IN
Supply
Supply
1
2
20
13 C +
14
10
17
2
1
3
8
–
C -
V-
V-
V+
Up/Down
1
1
is typically 2ms. After V
2
2
+ pins (pins 12 and 15)
– pins (pins 11 and 16)
Power
400k
400k
GND
Down
Down
SP233ACT
+5V INPUT
6
R
R
Up
Up
1
2
V
© Copyright 2000 Sipex Corporation
CC
7
T
T
GND
1
2
5k
5k
9
C +
C +
C -
C -
2
2
2
2
12
15
11
16
18
19
5
4
Receiver
Outputs
Tri–state
Tri–state
R IN
R IN
T OUT
T OUT
Enable
Enable
1
2
1
2
+
and