Datasheet

TRS3243E

SLLS789C –APRIL 2007– REVISED SEPTEMBER 2011

www.ti.com

DESCRIPTION/ORDERING INFORMATION

The TRS3243E device consists of three line drivers, five line receivers, and a dual charge-pump circuit with

±15-kV ESD (HBM and IEC61000-4-2, Air-Gap Discharge) and ±8-kV ESD (IEC61000-4-2, Contact Discharge)

protection on serial-port connection pins. 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. This

combination of drivers and receivers matches that needed for the typical serial port used in an IBM PC/AT, or

compatible. 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 (ROUT2B), which allows

applications using the ring indicator to transmit data while the device is powered down. The device 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 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, the driver outputs are disabled. If FORCEOFF is

set low, both drivers and receivers (except ROUT2B) 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, and should be done when driving

a serial mouse. With auto-powerdown enabled, the device is activated automatically when a valid signal is

applied to any receiver input. The INVALID output is used to notify the user if an RS-232 signal is present at any

receiver 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.

The TRS3243EC is characterized for operation from 0°C to 70°C. The TRS3243EI is characterized for operation

from –40°C to 85°C.

Table 1. ORDERING INFORMATION

PACKAGE

(1)

ORDERABLE PART NUMBER TOP-SIDE MARKING

SSOP – DB Reel of 2000 TRS3243ECDBR TRS3243EC

SOP – DW Reel of 2000 TRS3243ECDWR TRS3243EC

0°C to 70°C

TSSOP – PW Reel of 2000 TRS3243ECPWR RS43EC

QFN – RHB Reel of 2000 TRS3243ECRHBR RS43EC

SSOP – DB Reel of 2000 TRS3243EIDBR TRS3243ECI

SOP – DW Reel of 2000 TRS3243EIDWR TRS3243ECI

–40°C to 85°C

TSSOP – PW Reel of 2000 TRS3243EIPWR RS43EI

QFN – RHB Reel of 2000 TRS3243EIRHBR RS43EI

(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI

website at www.ti.com.

Product Folder Link(s): TRS3243E