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1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

EN

C1+

V+

C1−

C2+

C2−

V−

RIN

FORCEOFF

GND

DOUT

FORCEON

DIN

INVALID

ROUT

DESCRIPTION/ORDERING INFORMATION

TRS3221E

3-V TO 5.5-V SINGLE-CHANNEL RS-232 LINE DRIVER/RECEIVER

WITH

±15-kV IEC ESD PROTECTION

SLLS792 – JUNE 2007

• Battery-Powered, Hand-Held, and Portable

• ESD Protection for RS-232 Pins

Equipment

–

±15-kV Human-Body Model (HBM)

• PDAs and Palmtop PCs

–

±8 kV (IEC 61000-4-2, Contact Discharge)

• Notebooks, Subnotebooks, and Laptops

–

±15 kV (IEC 61000-4-2, Air-Gap Discharge)

• Digital Cameras

• Meets or Exceeds the Requirements of

• Mobile Phones and Wireless Devices

TIA/EIA-232-F and ITU v.28 Standards

• Operates With 3-V to 5.5-V V

• Operates up to 250 kbit/s

• One Driver and One Receiver

• Low Standby Current . . . 1 μA Typical

• External Capacitors . . . 4 × 0.1 μF

• Accepts 5-V Logic Input With 3.3-V Supply

• Alternative High-Speed Pin-Compatible Device

(1 Mbit/s)

–

TRSF3221E

• Auto-Powerdown Feature Automatically

Disables Drivers for Power Savings

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.