19-1339; Rev 0; 1/98
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
________________General Description
The MAX3224E/MAX3225E/MAX3226E/MAX3227E/
MAX3244E/MAX3245E are 3V-powered EIA/TIA-232
and V.28/V.24 communications interfaces with automat-
ic shutdown/wakeup features, high data-rate capabili-
ties, and enhanced electrostatic discharge (ESD)
protection. All transmitter outputs and receiver inputs
are protected to ±15kV using IEC 1000-4-2 Air-Gap
Discharge, ±8kV using IEC 1000-4-2 Contact Discharge,
and ±15kV using the Human Body Model.
All devices achieve a 1µA supply current using Maxim’s
revolutionary AutoShutdown Plus™ feature. These
devices automatically enter a low-power shutdown
mode when the RS-232 cable is disconnected or the
transmitters of the connected peripherals are inactive,
and the UART driving the transmitter inputs is inactive
for more than 30 seconds. They turn on again when
they sense a valid transition at any transmitter or receiv-
er input. AutoShutdown Plus saves power without
changes to the existing BIOS or operating system.
The MAX3225E/MAX3227E/MAX3245E also feature
MegaBaud™ operation, guaranteeing 1Mbps for high-
speed applications such as communicating with ISDN
modems. The MAX3224E/MAX3226E/MAX3244E guar-
antee 250kbps operation. The transceivers have a pro-
prietary low-dropout transmitter output stage enabling
true RS-232 performance from a +3.0V to +5.5V supply
with a dual charge pump. The charge pump requires
only four small 0.1µF capacitors for operation from a
3.3V supply. The MAX3224E–MAX3227E feature a logic-
level output (READY) that asserts when the charge
pump is regulating and the device is ready to begin
transmitting.
All devices are available in a space-saving SSOP pack-
age.
____________________________Features
o
ESD Protection for RS-232 I/O Pins:
±15kV—Human Body Model
±8kV—IEC1000-4-2, Contact Discharge
±15kV—IEC1000-4-2, Air-Gap Discharge
o
Latchup Free
o
1µA Supply Current
o
AutoShutdown Plus—EDN Innovation of the Year
o
Guaranteed Data Rate:
250kbps (MAX3224E/3226E/3244E)
1Mbps (MAX3225E/3227E/3245E)
o
Guaranteed Slew Rate:
6V/µs (MAX3224E/3226E/3244E)
24V/µs (MAX3225E/3227E/3245E)
o
Meets EIA/TIA-232 Specifications Down to 3.0V
o
Guaranteed Mouse Driveability
(MAX3244E/3245E)
o
Ready-to-Transmit Logic-Level Output
MAX3224E–MAX3227E/MAX3244E/MAX3245E
†
_______________Ordering Information
PART
MAX3224ECPP
MAX3224ECAP
MAX3224EEPP
MAX3224EEAP
MAX3225ECPP
MAX3225ECAP
MAX3225EEPP
MAX3225EEAP
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 Plastic DIP
20 SSOP
20 Plastic DIP
20 SSOP
20 Plastic DIP
20 SSOP
20 Plastic DIP
20 SSOP
________________________Applications
Notebook, Subnotebook, and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
Ordering Information continued at end of data sheet.
_____________________ Selector Guide
PART
NO. OF
GUARANTEED
AUTO-
READY
DRIVERS/
DATA RATE
SHUTDOWN
OUTPUT
(bps)
RECEIVERS
PLUS
2/2
2/2
1/1
1/1
3/5
3/5
250k
1M
250k
1M
250k
1M
—
—
1
MAX3224E
AutoShutdown Plus and MegaBaud are trademarks 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; 5,649,210; and other
patents pending.
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E
________________________________________________________________
Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
