TRSF3221 Datasheet, PDF (1/16 Pages) Texas Instruments – 3-V TO 5.5-V SINGLE-CHANNEL RS-232 COMPATIBLE LINE DRIVER/RECEIVER

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TRSF3221
3-V TO 5.5-V SINGLE-CHANNEL RS-232 COMPATIBLE LINE DRIVER/RECEIVER
SLLS857 – AUGUST 2007
FEATURES
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• Operates With 3-V to 5.5-V V_CC Supply
• Operates 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
APPLICATIONS
• Battery-Powered, Hand-Held, and Portable
Equipment
• PDAs and Palmtop PCs
• Notebooks, Sub-Notebooks, and Laptops
• Digital Cameras
• Mobile Phones and Wireless Devices
DB OR PW PACKAGE
(TOP VIEW)
EN 1
C1+ 2
V+ 3
C1− 4
C2+ 5
C2− ⁶
V− ⁷
RIN ⁸
16 FORCEOFF
15 V_CC
14 GND
13 DOUT
12 FORCEON
11 _DIN
10 _INVALID
9 _ROUT
DESCRIPTION/ORDERING INFORMATION
The TRSF3221 consists 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). The TRSF3221 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. The TRSF3221 operates 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 TRSF3221 does not sense a valid RS-232 signal on the receiver input, the driver output is
disabled. If FORCEOFF is set low and the enable (EN) input 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.
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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.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2007, Texas Instruments Incorporated