TRSF3238
3-V TO 5.5-V MULTICHANNEL RS-232 COMPATIBLE LINE DRIVER/RECEIVER
www.ti.com
SLLS859–AUGUST 2007
FEATURES
DB, DW, OR PW PACKAGE
(TOP VIEW)
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Auto-Powerdown Plus
Operates With 3-V to 5.5-V VCC Supply
C2+
GND
C2−
C1+
27 V+
26
1
28
Always-Active Noninverting Receiver Output
(ROUT1B)
2
3
V
CC
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Supports Operation From 250 kbit/s to
1 Mbit/s
V−
4
25 C1−
DOUT1
DOUT2
DOUT3
RIN1
5
24 DIN1
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Low Standby Current . . . 1 μA Typical
External Capacitors . . . 4 × 0.1 μF
Accepts 5-V Logic Input With 3.3-V Supply
Inter-Operable With TRSF3243
6
23
22
21
20
19
18
17
16
15
DIN2
7
DIN3
8
ROUT1
ROUT2
DIN4
9
RIN2
DOUT4
RIN3
10
11
12
13
14
RS-232 Bus-Pin ESD Protection Exceeds
ROUT3
DIN5
±15 kV Using Human-Body Model (HBM)
DOUT5
FORCEON
FORCEOFF
ROUT1B
INVALID
APPLICATIONS
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Battery-Powered Systems
PDAs
Notebooks
Subnotebooks
Laptops
Palmtop PCs
Hand-Held Equipment
Modems
Printers
DESCRIPTION/ORDERING INFORMATION
The TRSF3238 device consists of five line drivers, three line receivers, and a dual charge-pump circuit with
±15-kV ESD protection pin to pin (serial-port connection pins, including GND). 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 (ROUT1B), which allows applications using the ring indicator to transmit data
while the device is powered down. This device operates at data signaling rate up to 1 Mbit/s and at an increased
slew-rate range of 24 V/μs to 150 V/μs.
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 automatically activates 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.