Datasheet

1
FEATURES
APPLICATIONS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
C2+
C2−
V−
RIN1
RIN2
RIN3
RIN4
RIN5
DOUT1
DOUT2
DOUT3
DIN3
DIN2
DIN1
C1+
V+
V
CC
GND
C1−
FORCEON
FORCEOFF
INVALID
ROUT2B
ROUT1
ROUT2
ROUT3
ROUT4
ROUT5
DB, DW, OR PW PACKAGE
(TOP VIEW)
DESCRIPTION/ORDERING INFORMATION
SN65C3243 , SN75C3243
www.ti.com ................................................................................................................................................. SLLS353H – JUNE 1999 – REVISED SEPTEMBER 2008
3-V TO 5.5-V MULTICHANNEL RS-232 COMPATIBLE LINE DRIVER/RECEIVER
• Operates With 3-V to 5.5-V V
CC
Supply
• Always-Active Noninverting Receiver Output
(ROUT2B)
• Low Standby Current . . . 1 µ A Typ
• External Capacitors . . . 4 × 0.1 µ F
• Accepts 5-V Logic Input With 3.3-V Supply
• Inter-Operable With SN65C3238, SN75C3238
• Supports Operation From 250 kbit/s to
1 Mbit/s
• RS-232 Bus-Pin ESD Protection Exceeds
± 15 kV Using Human-Body Model (HBM)
• Latch-Up Performance Exceeds 100 mA Per
JESD 78, Class II
• Battery-Powered Systems
• PDAs
• Notebooks
• Laptops
• Palmtop PCs
• Hand-Held Equipment
The SN65C3243 and SN75C3243 consist of three line drivers, five line receivers, and a dual charge-pump circuit
with ± 15-kV ESD protection pin to pin (serial-port connection pins, including GND). This device 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. In addition, this 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 1 Mbit/s and
an increased slew-rate range of 24 V/ µ s to 150 V/ µ s.
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 µ A.
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 µ s. INVALID is low (invalid data) if all receiver input
voltages are between – 0.3 V and 0.3 V for more than 30 µ s. Refer to Figure 5 for receiver input levels.
1
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 © 1999 – 2008, 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.