
MAXT3221
3-V TO 5.5-V MULTICHANNEL RS-232 LINE DRIVER/RECEIVER
SLLS351 – JUNE 1999
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
Meet or Exceed the Requirements of
TIA/EIA-232-F and ITU v.28 Standards
Operate With 3-V to 5.5-V V
CC
Supply
Designed to Operate up to 1 Mbit/s
Low Standby Current . . . 1
μ
A Typical
External Capacitors . . . 4
×
0.1
μ
F
Accept 5-V Logic Input With 3.3-V Supply
Designed to be Interchangeable With
Maxim MAX3221C and MAX3221E
RS-232 Bus-Pin ESD Protection Exceeds
±
15-kV Using Human-Body Model (HBM)
Applications
– Battery-Powered Systems, PDAs,
Notebooks, Laptops, Palmtop PCs, and
Hand-Held Equipment
Package Options Include Plastic
Small-Outline (DW), Shrink Small-Outline
(DB), and Thin Shrink Small-Outline (PW)
Packages
description
The MAXT3221
devices consist of one line driver, one line receiver, and a dual charge-pump circuit with
±
15-kV
ESD protection pin-to-pin (serial-port connection pins, including GND). These devices provide the electrical
interface between an asynchronous communication controller and the serial-port connector and meet the
requirements of TIA/EIA-232-F. The charge pump and four small external capacitors allow operation from a
single 3-V to 5.5-V supply. These devices are designed to operate at data signaling rates up to 1 Mbit/s, with
an increased slew-rate range of 24 V/ s to 150 V/ 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 devices do not sense a valid RS-232 signal, the driver outputs are disabled. If FORCEOFF is
set low and EN is high, both drivers and receivers 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. With auto-powerdown enabled,
the devices are 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 the receiver input voltage is between –0.3 V and 0.3 V for more than
30
μ
s. Refer to Figure 4 for receiver input levels.
The MAXT3221C is characterized for operation over the temperature range of 0
°
C to 70
°
C. The MAXT3221I
is characterized for operation over the temperature range of –40
°
C to –85
°
C.
P
Copyright
1999, Texas Instruments Incorporated
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
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.
DB, DW, OR PW PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
EN
C1+
V+
C1–
C2+
C2–
V–
RIN
FORCEOFF
V
CC
GND
DOUT
FORCEON
DIN
INVALID
ROUT