19-0306; Rev 6; 3/99
1碌A Supply-Current, True +3V to +5.5V
RS-232 Transceivers with AutoShutdown
_______________General Description
The MAX3221/MAX3223/MAX3243 achieve 1碌A supply
current with Maxim鈥檚 revolutionary AutoShutdown鈩?fea-
ture. When the MAX3221/MAX3223/MAX3243 do not
sense a valid signal level on their receiver inputs, the
on-board power supply and drivers shut down. This
occurs if the RS-232 cable is disconnected or if the
transmitters of the connected peripheral are turned off.
The system turns on again when a valid level is applied
to any RS-232 receiver input. As a result, the system
saves power without changes to the existing BIOS or
operating system.
The MAX3221/MAX3223/MAX3243 transceivers are 3V-
powered EIA/TIA-232 and V.28/V.24 communications
interfaces intended for notebook computer applica-
tions. A proprietary, high-efficiency, dual charge-pump
power supply and a low-dropout transmitter combine to
deliver true RS-232 performance from a single +3.0V to
+5.5V supply. A guaranteed data rate of 120kbps pro-
vides compatibility with popular software for communi-
cating with personal computers.
The MAX3221/MAX3223/MAX3243 require only 0.1碌F
capacitors in 3.3V operation, and can operate from input
voltages ranging from +3.0V to +5.5V. They are ideal for
3.3V-only systems, mixed 3.3V and 5.0V systems, or
5.0V-only systems that require true RS-232 performance.
The MAX3221 is a 1-driver/1-receiver 16-pin SSOP ver-
sion of the 20-pin MAX3223 (2-driver/2-receiver). The
MAX3243 3-driver/5-receiver, complete serial port is
ideal for notebook or subnotebook computers. The
MAX3243 includes one complementary always-active
receiver. This receiver can monitor an external device
(such as a modem) in shutdown, without forward bias-
ing the protection diodes in a UART that may have V
CC
completely removed.
____________________________Features
o
1碌A Supply Current Achieved with AutoShutdown
o
Small 0.1碌F Capacitors
o
True RS-232 Operation from V
CC
= +3.0V to +5.5V
o
Meets EIA/TIA-562 Specifications Down to 2.7V
o
Guaranteed 120kbps Data Rate
o
6V/碌s Min Guaranteed Slew Rate
o
Smallest Single-Supply RS-232 Transceiver
(MAX3221)
o
Guaranteed Mouse Driveability (MAX3243)
o
Small TSSOP Package (MAX3223/MAX3243)
MAX3221/MAX3223/MAX3243*
________________________Applications
Notebook, Subnotebook, and Palmtop Computers
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
______________Ordering Information
PART
MAX3221CAE
MAX3221CUE鈥?/div>
MAX3221EAE
MAX3221EUE鈥?/div>
MAX3223CPP
MAX3223CAP
MAX3223CUP
MAX3223EPP
MAX3223EAP
MAX3223EUP
MAX3243CWI
MAX3243CAI
MAX3243CUI
MAX3243EWI
MAX3243EAI
MAX3243EUI
TEMP. RANGE
0掳C to +70掳C
0掳C to +70掳C
-40掳C to +85掳C
-40掳C to +85掳C
0掳C to +70掳C
0掳C to +70掳C
0掳C to +70掳C
-40掳C to +85掳C
-40掳C to +85掳C
-40掳C to +85掳C
0掳C to +70掳C
0掳C to +70掳C
0掳C to +70掳C
-40掳C to +85掳C
-40掳C to +85掳C
-40掳C to +85掳C
PIN-PACKAGE
16 SSOP
16 TSSOP
16 SSOP
16 TSSOP
20 Plastic DIP
20 SSOP
20 TSSOP
20 Plastic DIP
20 SSOP
20 TSSOP
28 Wide SO
28 SSOP
28 TSSOP
28 Wide SO
28 SSOP
28 TSSOP
_____________________Selector Guide
PART
MAX3221
MAX3223
MAX3243
Tx
1
2
3
Rx
1
2
5
V
CC
RANGE (V) AutoShutdown
3.0 to 5.5
3.0 to 5.5
3.0 to 5.5
Yes
Yes
Yes
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
鈥燜uture
product鈥攃ontact factory for availability.
AutoShutdown is a trademark of Maxim Integrated Products.
* Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
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