TRS3221E
3-V TO 5.5-V SINGLE-CHANNEL RS-232 LINE DRIVER/RECEIVER
WITH ±15-kV IEC ESD PROTECTION
www.ti.com
SLLS792–JUNE 2007
FEATURES
APPLICATIONS
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Battery-Powered, Hand-Held, and Portable
Equipment
•
ESD Protection for RS-232 Pins
–
–
–
±15-kV Human-Body Model (HBM)
•
•
•
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PDAs and Palmtop PCs
Notebooks, Subnotebooks, and Laptops
Digital Cameras
±8 kV (IEC 61000-4-2, Contact Discharge)
±15 kV (IEC 61000-4-2, Air-Gap Discharge)
•
Meets or Exceeds the Requirements of
TIA/EIA-232-F and ITU v.28 Standards
Mobile Phones and Wireless Devices
•
•
•
•
•
•
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Operates With 3-V to 5.5-V VCC Supply
Operates up to 250 kbit/s
DB OR PW PACKAGE
(TOP VIEW)
One Driver and One Receiver
EN
C1+
V+
FORCEOFF
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
Low Standby Current . . . 1 μA Typical
External Capacitors . . . 4 × 0.1 μF
Accepts 5-V Logic Input With 3.3-V Supply
V
CC
GND
C1−
C2+
C2−
V−
DOUT
FORCEON
DIN
Alternative High-Speed Pin-Compatible Device
(1 Mbit/s)
INVALID
ROUT
–
TRSF3221E
RIN
•
Auto-Powerdown Feature Automatically
Disables Drivers for Power Savings
DESCRIPTION/ORDERING INFORMATION
The TRS3221E is a single driver, single receiver RS-232 solution operating from a single VCC supply. The
RS-232 pins provide IEC G1000-4-2 ESD protection. The device meets the requirements of TIA/EIA-232-F and
provides the electrical interface between an asynchronous communication controller and the serial-port
connector. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V
supply. These devices operate at data signaling rates up to 250 kbit/s and a maximum of 30-V/μs driver output
slew rate.
Flexible control options for power management are available when the serial port is inactive. 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 on the receiver input, the driver output is disabled.
If FORCEOFF is set low and EN is high, both the driver and receiver are shut off, and the supply current is
reduced to 1 μA. Disconnecting the serial port or turning off the peripheral drivers causes the auto-powerdown
condition to occur. Auto-powerdown can be disabled when FORCEON and FORCEOFF are high.
With auto-powerdown enabled, the device is activated automatically when a valid signal is applied to the
receiver input. The INVALID output notifies the user if an RS-232 signal is present at the receiver input. INVALID
is high (valid data) if the receiver input voltage is greater than 2.7 V or less than –2.7 V, or has been between
–0.3 V and 0.3 V for less than 30 μs. INVALID is low (invalid data) if the receiver input voltage is between –0.3 V
and 0.3 V for more than 30 μs. Refer to Figure 5 for receiver input levels.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright © 2007, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.