low power, up to 250 Kbps, RS-232 drivers and receivers
Features
■ ESD protection for RS-232 I/O pins ± 15 kV
human body model, ± 8 kV IEC 1000-4-2
contact discharge
■ 300 µA supply current
■ 250KBps minimum guarantee data rate
■ 6 V/µs minimum guarantee slew rate
■ Meet EIA/TIA-232 specification down to 3 V
■ Available in SSOP20 and TSSOP20
ST3222EB
ST3222EC
± 15 kV ESD protected, 3 to 5.5 V
TSSOP
SSOP
Description
The ST3222E is a 3 V powered EIA/TIA-232 and
V.28/V.24 communications interface with low
power requirements, high data-rate capabilities
and enhanced electrostatic discharge (ESD)
protection to ± 8 kV using IEC1000-4-2 Contact
Discharge and ±15 kV using the Human Body
Model. ST3222E has a proprietary low dropout
transmitter output stage providing true RS-232
performance from 3 to 5 V supplies with a dual
charge pump. The charge pump requires only four
small 0.1 mF external capacitors for operation
form 3 V supply. The device has two receivers and
two drivers. The ST3222E features a 1 mA
shutdown mode that reduces power consumption
and extends battery life in portable systems. Its
receivers can remain active in shutdown mode,
allowing external devices such as modems to be
monitored using only 1 mA supply current. The
device is guaranteed to run at data rates of 250
Kbps while maintaining RS-232 output levels.
Table 1. Device summary
Order codes
Temperature
range
Package Packaging
Typical applications are Notebook, Sub-notebook
and Palmtop Computers, Battery Powered
Equipment, Hand-Held Equipment, Peripherals
and Printers.
ST3222ECPR 0 to 70 °C SSOP20 (tape and reel) 1350 parts per reel
ST3222EBPR -40 to 85 °C SSOP20 (tape and reel) 1350 parts per reel
ST3222ECTR 0 to 70 °C TSSOP20 (tape and reel) 2500 parts per reel
ST3222EBTR -40 to 85 °C TSSOP20 (tape and reel) 2500 parts per reel
January 2008 Rev 8 1/15
www.st.com
15
Contents ST3222E
Contents
1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2/15
ST3222E Pin configuration
1 Pin configuration
Figure 1. Pin connection
Table 2. Pin description
Pin n° Symbol Name and function
1EN
2C
1
Receiver enable control. drive low for normal operation. Drive high to force the
receivers outputs (R_OUT) into a high-impedance state.
+ Positive terminal for the first charge pump capacitor
3 V+ 5.5V Generated by the charge pump.
4C
5C
6C
- Negative terminal for the first charge pump capacitor
1
+ Positive terminal for the second charge pump capacitor
2
- Negative terminal for the second charge pump capacitor
2
7 V- -5.5V Generated by the charge pump.
8T2
OUT
9R2
10 R2
OUT
Second transmitter output voltage
Second receiver input voltage
IN
Second receiver output voltage
11 NC Not connected
12 T2
13 T1
Second transmitter input voltage
IN
First transmitter input voltage
IN
14 NC Not connected
15 R1
16 R1
17 T1
OUT
OUT
First receiver output voltage
First receiver input voltage
IN
First transmitter output voltage
18 GND Ground
19 V
CC
Supply voltage
20 SHDN Active low shutdown control input. drive low to shut-down transmitter and charge pump
3/15
Absolute maximum ratings ST3222E
2 Absolute maximum ratings
Table 3. Absolute maximum ratings
Symbol Parameter Value Unit
V
CC
V+ Doubled voltage terminal (V
V- Inverted voltage terminal 0.3 to -7 V
V+ +|V-| 13 V
T
IN
R
IN
T
OUT
R
OUT
t
SHORT
Supply voltage -0.3 to 6 V
- 0.3) to 7 V
CC
Transmitter input voltage range -0.3 to 6 V
Receiver input voltage range ± 25 V
Transmitter output voltage range ± 13.2 V
Receiver output voltage range -0.3 to (VCC + 0.3) V
Transmitter output short to gnd time Continuous
Note: Absolute maximum ratings are those values beyond which damage to the device may
occur. Functional operation under these condition is not implied.
Externally applied V+ and V- can have a maximum magnitude of +7 V, but their absolute
addition can not exceed 13 V.
Running on internal charge pump, intrinsic self limitation allows exceeding those values
without any damage.
Startup voltage sequence (V
, then V+, then V-) is critical, therefore it is not recommended
CC
to use this device using externally applied voltage to V+ and V-.
Table 4. Shutdown and enable control truth table
SHDN EN T-OUT R-OUT
0 0 High Z Active
0 1 High Z High Z
1 0 Active Active
1 1 Active High Z
Table 5. ESD performance: transmitter outputs, receiver inputs
Symbol Parameter Test conditions Min. Typ. Max. Unit
ESD ESD protection voltage Human body model ±15 kV
ESD ESD protection voltage IEC-1000-4-2 ±8kV
4/15
ST3222E Electrical characteristics
3 Electrical characteristics
Table 6. Electrical characteristics (C
otherwise specified. Typical values are referred to T
- C4 = 0.1 µF, VCC = 3 V to 5.5 V, TA = -40 to 85 °C, unless
1
= 25 °C)
A
Symbol Parameter Test conditions Min. Typ. Max. Unit
I
SUPPLYVCC
I
SHDN
power supply current No load, SHDN = VCC, TA = 25°C 0.3 1 mA
Shutdown supply current No load, SHDN = VCC, TA = 25°C 1 10 µA
Table 7. Logic input electrical characteristics (C1 - C4 = 0.1 µF, VCC = 3 V to 5.5 V,
T
= -40 to 85 °C, unless otherwise specified. Typical values are referred to TA = 25 °C)
A
Symbol Parameter Test conditions Min. Typ. Max. Unit
V
Input logic threshold low T-IN, EN, SHDN (Note: 1)0.8V
IL
VCC = 3.3 V 2
V
V
HYS
I
Input logic threshold high
IH
Transmitter input
hysteresis
Input leakage current T-IN, EN, SHDN ± 0.01 ± 1µA
IL
= 5 V 2.4
V
CC
0.25 V
Note: 1 Transmitter input hysteresis is typically 250 mV
Table 8. Transmitter electrical characteristics (C1 - C4 = 0.1 µF VCC = 3 V to 5.5 V,
T
= -40 to 85 °C, unless otherwise specified. Typical values are referred to TA = 25 °C)
A
Symbol Parameter Test conditions Min. Typ. Max. Unit
V
V
R
I
TOUT
TOUT
TSC
I
TOL
Output voltage swing
Transmitter output
resistance
Output short circuit
current
Output leakage current
All transmitter outputs are loaded with
3 KΩ to GND
V
= V+ = V- = 0 V, V
CC
= 0 or 3 V to 3.6 V, V
V
CC
= ± 2 V 300 10M Ω
OUT
= ± 12 V
OUT
Transmitters disable
± 5 ± 5.4 V
± 60 mA
± 25 µA
5/15
Electrical characteristics ST3222E
Table 9. Receiver electrical characteristics (C
T
= -40 to 85 °C, unless otherwise specified. Typical values are referred to TA = 25 °C)
A
Symbol Parameter Test conditions Min. Typ. Max. Unit
- C4 = 0.1 µF, VCC = 3 V to 5.5 V,
1
I
V
V
V
V
RIHYS
R
V
V
OL
RIN
RIL
RIH
RIN
ROL
ROH
Output leakage current R-OUT, EN = VCC, receiver disabled ± 0.05 ± 10 µA
Receiver input voltage
operating range
Input threshold low
Input threshold high
T
= 25°C, VCC = 3.3 V 0.6 1.2
A
= 25°C, VCC = 5 V 0.8 1.5
T
A
T
= 25°C, VCC = 3.3 V 1.5 2.4
A
= 25°C, VCC = 5 V 1.8 2.4
T
A
-25 25 V
Input hysteresis 0.5 V
Input resistance TA = 25°C 3 5 7 KΩ
Output voltage low I
Output voltage high I
= 1.6 mA 0.4 V
OUT
-
V
= -1 mA VCC-0.6
OUT
CC
0.1
Table 10. Timing characteristics (C1 - C4 = 0.1 µF, VCC = 3 V to 5.5 V, TA = -40 to 85 °C, unless
otherwise specified. Typical values are referred to T
Symbol Parameter Test conditions Min. Typ. Max. Unit
= 3 KΩ, CL2= 1000 pF
R
D
t
PHLR
t
PLHR
|t
PHLT
- t
t
OER
R
THL
Data transfer rate
Propagation delay input to
output
Transmitter propagation
|
delay difference
Receiver output enable
time
(1)
L
one transmitter switching
to R
R
XIN
, CL = 150 pF 0.15 µs
XOUT
Normal operation 50 ns
= 25 °C)
A
250 Kbps
200 ns
V
V
V
t
ODR
|t
PHLR
- t
THR
Receiver output disable
time
Receiver propagation
|
delay difference
Normal operation 50 ns
= 25°C RL = 3 KΩ to 7 KΩ
T
A
= 3.3 V
V
CC
measured from +3V to -3V or -3V to +3V
= 150 pF to 1000 pF
C
S
Transition slew rate
RT
L
T
= 25°C RL = 3 KΩ to 7 KΩ
A
= 3.3 V
V
CC
measured from +3V to -3V or -3V to +3V
= 150 pF to 2500 pF
C
L
1. Transmitter Skew is measured at the transmitter zero cross points
6/15
50 ns
630V/µs
430V/µs
ST3222E Application circuits
4 Application circuits
Figure 2. Application schematic
Table 11. Capacitance value (µF)
V
CC
C1 C2 C3 C4 Cbypass
3.0 to 3.6 0.1 0.1 0.1 0.1 0.1
4.5 to 5.5 0.047 0.33 0.33 0.33 0.33
3.0 to 5.5 0.22 0.1 0.1 0.1 0.22
7/15
Typical performance characteristics ST3222E
5 Typical performance characteristics
(unless otherwise specified TJ = 25 °C)
Figure 3. Output current vs output high
voltage
Figure 4. Output current vs output high
voltage
Figure 5. Output current vs output low
voltage
Figure 7. Voltage transfer characteristics for
transmitter inputs
Figure 6. Output current vs output low
voltage
Figure 8. Receiver input resistance
8/15
ST3222E Package mechanical data
6 Package mechanical data
In order to meet environmental requirements, ST offers these devices in ECOPACK®
packages. These packages have a lead-free second level interconnect. The category of
second level interconnect is marked on the package and on the inner box label, in
compliance with JEDEC Standard JESD97. The maximum ratings related to soldering
conditions are also marked on the inner box label. ECOPACK is an ST trademark.
ECOPACK specifications are available at: www.st.com
9/15
Package mechanical data ST3222E
SSOP20 mechanical data
mm. inch.
Dim.
Min. Typ. Max. Min. Typ. Max.
A 2 0.079
A1 0.05 0.002
A2 1.65 1.75 1.85 0.065 0.069 0.073
b 0.22 0.38 0.009 0.015
c0.09 0.25 0.004 0.010
D6.9 7.2 7.5 0.272 0.283 0.295
E 7.4 7.88.2 0.2910.307 0.323
E1 5 5.3 5.6 0.197 0.209 0.220
e 0.65 BSC 0.0256 BSC
K0°4°8°0°4°8°
L 0.55 0.75 0.95 0.022 0.030 0.037
A2
A
A1
b
e
K
c
L
E
D
E1
PIN 1 IDENTIFICATION
1
10/15
0061436C
ST3222E Package mechanical data
TSSOP20 mechanical data
mm. inch.
Dim.
Min. Typ. Max. Min. Typ. Max.
A 1.2 0.047
A1 0.05 0.15 0.002 0.004 0.006
A2 0.8 1 1.05 0.031 0.039 0.041
b 0.19 0.30 0.007 0.012
c0.09 0.20 0.004 0.0079
D 6.4 6.5 6.6 0.252 0.256 0.260
E 6.2 6.4 6.6 0.244 0.252 0.260
E1 4.3 4.4 4.48 0.169 0.173 0.176
e 0.65 BSC 0.0256 BSC
K0° 8°0° 8°
L 0.45 0.60 0.75 0.018 0.024 0.030
A2
A
A1
b
e
K
c
L
E
D
E1
PIN 1 IDENTIFICATION
1
0087225C
11/15
Package mechanical data ST3222E
Tape & reel SSOP20 mechanical data
mm. inch.
Dim.
Min. Typ. Max. Min. Typ. Max.
A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N60 2.362
T 22.4 0.882
Ao 8.4 8.6 0.3310.339
Bo 7.7 7.9 0.303 0.311
Ko 2.93.1 0.114 0.122
Po 3.9 4.1 0.153 0.161
P 11.9 12.1 0.468 0.476
12/15
ST3222E Package mechanical data
Tape & reel TSSOP20 mechanical data
mm. inch.
Dim.
Min. Typ. Max. Min. Typ. Max.
A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N60 2.362
T 22.4 0.882
Ao 6.8 7 0.268 0.276
Bo 6.9 7.1 0.272 0.280
Ko 1.7 1.9 0.067 0.075
Po 3.9 4.1 0.153 0.161
P 11.9 12.1 0.468 0.476
13/15
Revision history ST3222E
7 Revision history
Table 12. Document revision history
Date Revision Changes
22-Mar-2006 6 Order codes updated.
23-Aug-2007 7 Added Ta b le 1 in cover page.
21-Jan-2008 8 Added note on Ta bl e 3.
14/15
ST3222E
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