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EN

C1+

V+

C1−

C2+

C2−

V−

RIN

FORCEOFF

GND

DOUT

FORCEON

DIN

INVALID

ROUT

APPLICATIONS

DESCRIPTION/ORDERING INFORMATION

SN65C3221E, SN75C3221E

3-V TO 5.5-V SINGLE-CHANNEL RS-232 1-Mbit/s LINE DRIVER/RECEIVER

WITH

±15-kV IEC ESD PROTECTION

SLLS694A – NOVEMBER 2005 – REVISED DECEMBER 2005

•

ESD Protection for RS-232 Pins

–

±15-kV Human-Body Model (HBM)

–

±8-kV IEC 61000-4-2 Contact Discharge

–

±15-kV IEC 61000-4-2 Air-Gap Discharge

•

•

Operate up to 1 Mbit/s

•

Low Standby Current . . . 1

µA Typ

•

External Capacitors . . . 4

× 0.1 µF

•

Accepts 5-V Logic Input With 3.3-V Supply

•

RS-232 Bus-Pin ESD Protection Exceeds

±15

kV Using Human-Body Model (HBM)

•

Auto-Powerdown Feature Automatically

Disables Drivers for Power Savings

•

Battery-Powered, Hand-Held, and Portable

Equipment

•

PDAs and Palmtop PCs

•

Notebooks, Sub-Notebooks, and Laptops

•

Digital Cameras

•

Mobile Phones and Wireless Devices

The SN65C3221E and SN75C3221E consist of one line driver, one line receiver, and a dual charge-pump circuit

with

±15-kV IEC ESD protection pin to pin (serial-port connection pins, including GND). These devices provide

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 1 Mbit/s and a driver output slew rate of 24 V/

µs to 150 V/µs.

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 devices do 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. See 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 © 2005, 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.