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
Page 2
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
Page 3
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
Page 4
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.
Input Logic Threshold High T-IN, FORCEON, FORCEOFF
TIH
Transmitter Input
THYS
Hysteresis
I
Input Leakage CurrentT-IN, FORCEON, FORCEOFF±
IL
I
Output Leakage CurrentReceiver Disabled
OL
Output Voltage LowI
OL
Output Voltage HighI
OH
= 25°C)
A
VCC = 3.3 or 5.0V TA = 25°C
All R_IN openFORCEOFF
All R_IN openFORCEOFF
VCC = 3.3 or 5.0V TA = 25°C
FORCEON = FORCEOFF
= 25°C)
A
VCC = 3.3V
V
= 5V
CC
= 1.6mA0.4V
OUT
= -1mAVCC-0.6 VCC-0.1V
OUT
= V
CC
= GND
= VCCNo Load
2
2.4
110
110
0.31mA
0.5V
±
0.01
0.05
1.0
±
10
±
A
µ
A
µ
V
V
A
µ
A
µ
AUTO-POWERDOWN ELECTRICAL CHARACTERISTICS
(C
- C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.
1
Typical values are referred to T
SymbolParameterTest ConditionsMin.Typ.Max.Unit
V
V
V
V
t
t
Receiver Input Threshold to
RITE
Transmitter Enabled
Receiver Input Threshold to
RITD
Transmitter Disabled
INVALID Output Voltage
IOL
LOW
INVALID Output Voltage
IOH
HIGH
Receiver Threshold to
t
WU
Transmitter Enabled
Receiver Positive or
invh
Negative Threshold to
INVALID
Receiver Positive or
invL
Negative Threshold to
INVALID
HIGH
LOW
= 25°C)
A
Positive Threshold
2.7V
Negative Threshold2.7
1µA Supply Current-0.30.3V
0.4V
VCC-0.6V
I
= 1.6mA250
OUT
I
= -1mA1
OUT
30
V
s
µ
s
µ
s
µ
4/11
Page 5
ST3243
TRANSMITTER 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
V
R
V
Output Voltage SwingAll Transmitter outputs are loaded with
TOUT
Output ResistanceVCC = V+ = V- = 0VV
OUT
I
Output Short Circuit Current
SC
Transmitter Output Voltage T1IN = T2IN = GND,T3IN = V
OT
RECEIVER ELECTRICAL CHARACTERISTICS
(C
- C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.
1
Typical values are referred to T
SymbolParameterTest ConditionsMin.Typ.Max.Unit
V
V
V
V
RIHYS
R
Receiver Input Voltage
RIN
Operating Range
RS-232 Input Threshold
RIL
Low
RS-232 Input Threshold
RIH
High
Input Hysteresis0.5V
Input ResistanceTA = 25°C357K
RIN
= 25°C)
A
3KΩ to GND
OUT
T3OUT loaded with 3KΩ to GND
T1OUT and T2OUT loaded with 2.5mA
each
= 25°C)
A
TA = 25°CVCC = 3.3V
T
= 25°CVCC = 5.0V
A
TA = 25°CVCC = 3.3V
T
= 25°CVCC = 5.0V
A
5
±
5.4V
±
= ± 2V30010M
35
±
5V
CC
±
-2525V
0.6
0.8
1.2
1.2
1.5
1.8
60mA
±
2.4
2.4
Ω
V
V
Ω
TIMING CHARACTERISTICS
(C
- C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified.
1
Typical values are referred to T
SymbolParameterTest ConditionsMin.Typ.Max.Unit
D
Maximum Data RateRL = 3K
R
t
t
T_SKEW
t
R_SKEW
t
t
S
Receiver Propagation Delay RIN to R
PHL
t
PLH
Transmitter Skew100ns
Receiver Skew50ns
Receiver Positive or
INVH
negative Threshold to
INVALID
Receiver Positive or
INVL
negative Threshold to
INVALID
Transition Slew RateTA = 25°C RL = 3K to 7K
RT
HIGH
LOW
= 25°C)
A
CL= 1000pF
Ω
one trasmitter switching
OUT
CL = 150pF0.15
Ω
measured from +3V to -3V or -3V to +3V
C
= 150pF to 1000pF
L
C
= 150pF to 2500pF
L
VCC = 3.3V
250400Kbps
1
30
6
4
30
30
V/µs
V/µs
s
µ
s
µ
s
µ
5/11
Page 6
ST3243
APPLICATION CIRCUITS
CAPACITANCE VALUE (µF)
V
CC
3.0 to 3.60.10.10.10.10.1
4.5 to 5.50.0470.330.330.330.33
3.0 to 5.50.221.01.01.00.22
6/11
C1C2C3C4Cbypass
Page 7
TYPICAL PERFORMANCE CHARACTERISTICS (unless otherwise specified Tj = 25°C)
Figure 1 : INVALID HIGH Threshold Time
Figure 4 : TReceiver Output Enab le & Disable
Time
ST3243
Figure 2 : INVALID LOW Threshold Time
Figure 3 : Receiver Propagation Delay
Figure 5 : Output Current vs Output High Voltage
Figure 6 : Output Current vs Output Low Voltage
7/11
Page 8
ST3243
SO-28 MECHANICAL DATA
DIM.
MIN.TYPMAX.MIN.TYP.MAX.
A2.650.104
a10.10.30.0040.012
b0.350.490.0140.019
b10.230.320.0090.012
C0.50.020
c145° (typ.)
D17.7018.100.6970.713
E10.0010.650.3930.419
e1.270.050
e316.510.650
F7.407.600.2910.300
L0.501.270.0200.050
S8° (max.)
mm.inch
8/11
0016023
Page 9
ST3243
SSOP28 MECHANICAL DATA
mm.inch
DIM.
MIN.TYPMAX.MIN.TYP.MAX.
A20.079
A10.0500.002
A21.651.751.850.0650.0690.073
b0.220.380.0090.015
c0.090.250.0040.010
D9.910.210.50.3900.4020.413
E7.47.88.20.2910.3070.323
E155.35.60.1970.2090.220
e0.65 BSC0.0256 BSC
K0°10°0°10°
L0.550.750.950.0220.0300.037
9/11
Page 10
ST3243
TSSOP28 MECHANICAL DATA
mm.inch
DIM.
MIN.TYPMAX.MIN.TYP.MAX.
A1.20.047
A10.050.150.0020.0040.006
A20.811.050.0310.0390.041
b0.190.300.0070.012
c0.090.200.0040.0089
D9.69.79.80.3780.3820.386
E6.26.46.60.2440.2520.260
E14.34.44.480.1690.1730.176
e0.65 BSC0.0256 BSC
K0°8°0°8°
L0.450.600.750.0180.0240.030
10/11
0128292B
Page 11
ST3243
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility f or t he
consequences of use of such informatio n nor for any infringement of paten ts or o ther rig hts of t hird part ies which ma y result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previousl y suppl ied. STM icroel ectronics produc ts are not auth orized for use as c ritica l compone nts in l ife s upport dev ices or
systems without express written approval of STMicroelectronics.
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