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C2 +

GND

C2−

V−

DOUT1

DOUT2

DOUT3

RIN1

RIN2

DOUT4

RIN3

DOUT5

FORCEON

FORCEOFF

C1+

V+

C1−

DIN1

DIN2

DIN3

ROUT1

ROUT2

DIN4

ROUT3

DIN5

ROUT1B

INVALID

DB OR PW PACKAGE

(TOP VIEW)

APPLICATIONS

DESCRIPTION/ORDERING INFORMATION

TRS3238

3-V TO 5.5-V MULTICHANNEL RS-232 LINE DRIVER/RECEIVER

WITH

±15-kV ESD (HBM) PROTECTION

SLLS817 – JULY 2007

• RS-232 Bus-Pin ESD Protection Exceeds

±15 kV Using Human-Body Model (HBM)

• Meets or Exceeds the Requirements of

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

• Operates With 3-V to 5.5-V V

• Operates up to 250 kbit/s

• Five Drivers and Three Receivers

• Low Standby Current . . . 1 μA Typical

• External Capacitors . . . 4 × 0.1 μF

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

• Always-Active Noninverting Receiver Output

(ROUT1B)

• Alternative High-Speed Pin-Compatible Device

(1 Mbit/s)

–

TRSF3238

• Battery-Powered Systems

• PDAs

• Notebooks

• Subnotebooks

• Laptops

• Palmtop PCs

• Hand-Held Equipment

• Modems

• Printers

The TRS3238 consists of five line drivers, three line receivers, and a dual charge-pump circuit with

±15-kV ESD

(HBM) protection pin to pin (serial-port connection pins, including GND). The device meets the requirements of

TIA/EIA-232-F and provides the electrical interface between notebook and subnotebook computer applications.

The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V supply. In

addition, the device includes an always-active noninverting output (ROUT1B), which allows applications using

the ring indicator to transmit data while the device is powered down. The TRS3238 operates 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 featured when the serial port and driver inputs are inactive.

The auto-powerdown plus feature functions when FORCEON is low and FORCEOFF is high. During this mode

of operation, if the device does not sense valid signal transitions on all receiver and driver inputs for

approximately 30 s, the built-in charge pump and drivers are powered down, reducing the supply current to

1

μA. By disconnecting the serial port or placing the peripheral drivers off, auto-powerdown plus occurs if there

is no activity in the logic levels for the driver inputs. Auto-powerdown plus can be disabled when FORCEON and

FORCEOFF are high. With auto-powerdown plus enabled, the device activates automatically when a valid signal

is applied to any receiver or driver input. INVALID is high (valid data) if any 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 all receiver input voltages are 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.