The ST3243 device consists of 3 drivers, 5
receivers and a dual charge-pump circuit. The
device meets the requirements of EIA/TIA and
V.28/V.24 comuni cation standards providing hi gh
data rate capability.
The receiver R2 is always active to implement a
wake-up feature for serial port.
The ST3243 has a proprietary low-dropout
transmitter output stage enabling true RS-232
performance from a 3.0V to 5.5V supply with a
dual charge pump. The device is guaranteed to
run at data rates of 250kbps while maintaining
RS-232 output levels.
The Auto-powerdown feature functions when
FORCEON is low and FORCEOFF
is high. During
this mode of operation, if the device does not
sense a valid RS-232 signal, the driver outputs are
disabled. If FORCEOFF
is set low, both drivers
and receivers (expert R2B) are shut off, and
supply current is reduced to 1mA. Disconnecting
SOP
SSOP
TSSOP
the serial port or turning off the p eripheral drives
causes the auto-powerdown condition to occur.
Auto-powerdown can be disabled when
FORCEON and FORCEOFF
are high, and should
be done when driving a serial mouse. With
Auto-powerdown enable d, the d evice is act ivated
automatically when a valid signal is applied to any
receiver i nput.
Typical application are in notebook, subnot ebook,
palmtop computers, battery-powered equipment,
hand-held equipment, peripherals and printers.
1/11May 2002
ST3243
ORDERING CODES
Type
Temperature
Range
PackageComments
ST3243CD0 to 70 °CSO-28 (Tube)27parts per tube / 12tube per box
ST3243BD-40 to 85 °CSO-28 (Tube)27parts per tube / 12tube per box
ST3243CDR0 to 70 °CSO-28 (Tape & Reel)1000 parts per reel
ST3243BDR-40 to 85 °CSO-28 (Tape & Reel)1000 parts per reel
ST3243CPR0 to 70 °CSSOP-28 (Tape & Reel)1350 parts per reel
ST3243BPR-40 to 85 °CSSOP-28 (Tape & Reel)1350 parts per reel
ST3243CTR0 to 70 °CTSSOP28 (Tape & Reel)2500 parts per reel
ST3243BTR-40 to 85 °CTSSOP28 (Tape & Reel)2500 parts per reel
PIN DESCRIPTION
PlN N°SYMBOLNAME AND FUNCTION
+Positive Terminal of Inverting Charge Pump Capacitor
1
2
3V--5.5V Generated by the Charge Pump
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25GNDGround
26
27V+5.5V Generated by the Charge Pump
28
C
2
C
-Negative Terminal of Inverting Charge Pump Capacitor
2
R1
IN
R2
IN
R3
IN
R4
IN
R5
IN
T1
OUT
T2
OUT
T3
OUT
T3
IN
T2
IN
T1
IN
R5
OUT
R4
OUT
R3
OUT
R2
OUT
R1
OUT
R2
OUTB
INVALID
First Receiver Input Voltage
Second Receiver Input Voltage
Third Receiver Input Voltage
Fourth Receiver Input Voltage
Fifth Receiver Input Voltage
First Transmitter Output Voltage
Second Transmitter Output Voltage
Third Transmitter Output Voltage
Third Transmitter Input Voltage
Second Transmitter Input Voltage
First Transmitter Input Voltage
Fifth Receiver Output Voltage
Fourth Receiver Output Voltage
Third Receiver Output Voltage
Second Receiver Output Voltage
First Receiver Output Voltage
Non-inverting Complementary Receiver Output, always active
for wake-up
Output of the valid signal detector. Indicates if a valid RS-232
level is present on receiver inputs logic "1"
FORCEOFF
Drive low to shut down transmitters and on-board power
supply. This over-rides all automatic circuitry and FORCEON
FORCEONDrive high to override automatic circuitry keeping transmitters
on (FORCEOFF
-Negative Terminal of Voltage- Charge Pump Capacitor
C
1
V
CC
+Positive Terminal of Voltage- Charge Pump Capacitor
C
1
Supply Voltage
must be high)
2/11
PIN CONFIGURATION
ST3243
TRUTH TABLE
FORCE OFF
T
OUT
R
OUT
0HIGH ZHIGH ZACTIVE *
1ACTIVE *ACTIVE *ACTIVE *
* If the part is in auto-powerdown mode (FORCE OFF = VCC, FORCE ON = GND) it is shutdown , if no valid R S- 232 levels are present on
all receiver input
R
2OUTB
ABSOLUTE MAXIMUM RATINGS
SymbolParameterValueUnit
V
CC
V+
V-Inverted Voltage Terminal0.3 to -7V
V+ +|V-|13V
FORCEON,
FORCEOFF,
T
IN
R
IN
T
OUT
R
OUT ROUTB
INVALID
t
SHORT
T
stg
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition i s
not implied. V+ and V- can have a maximum magnitude of +7V, but their absolute addition can not exceed 13 V.
(*) The device doesn’t m eet 1KV ESD HBM
Supply Voltage
Doubled Voltage Terminal(V
Input Voltage
Receiver Input Voltage Range
Transmitter Output Voltage Range
Receiver Output Voltage Range
Short Circuit Duration on T
(one at a time)
OUT
Storage Temperature Range
-0.3 to 6V
-0.3) to 7
CC
-0.3 to 6V
25V
±
13.2V
±
-0.3 to (V
CC
+ 0.3)
Continuous
-65 to 150°C
V
V
3/11
ST3243
ELECTRICAL CHARACTERISTICS
- C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.
(C
1
Typical values are referred to T
SymbolParameterTest ConditionsMin.Typ.Max.Unit
I
ASHDN
I
SHDN
I
SHDN
Supply Current
Auto-powerdown
Shutdown Supply CurrentVCC = 3.3 or 5.0V TA = 25°C
Supply Current
Auto-powerdown Disabled
LOGIC INPUT ELECTRICAL CHARACTERISTICS
(C
- C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.