Datasheet

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].
General Description
The MAX221 is a +5V-powered, single transmit/receive
RS-232 and V.28 communications interface with auto-
matic shutdown/wake-up features and high data rate
capabilities.
The MAX221 achieves a low 1µA supply current with
Maxim’s revolutionary AutoShutdown™ feature.
AutoShutdown saves power without changes to the
existing BIOS or operating system by entering low-
power shutdown mode when the RS-232 cable is dis-
connected, or when the transmitter of the connected
peripheral is off. The MAX221 wakes up and drives the
INVALID pin high when an active RS-232 cable is con-
nected, signaling the host that a peripheral is connect-
ed to the communications port.
The MAX221 is available in a 16-pin SSOP package as
well as a 16-pin TSSOP that uses 50% less board space
than a 16-pin SO. For an equivalent RS-232 transceiver
with enhanced ±15kV ESD protection, refer to the
MAX221E data sheet.
Applications
Maintenance/Diagnostic Ports
Industrial Systems
Telecommunications
Set-Top Boxes
Features
♦ Single RS-232 Transceiver in a Small 16-Pin
TSSOP Package
♦ 1µA Supply Current
♦ AutoShutdown Saves Power Without
Changes to BIOS
♦ Guaranteed 250kbps Data Rate
MAX221
+5V, 1µA, Single RS-232 Transceiver
with AutoShutdown
________________________________________________________________ Maxim Integrated Products 1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
EN FORCEOFF
V
CC
GND
TOUT
FORCEON
TIN
INVALID
ROUT
TOP VIEW
MAX221
TSSOP/SSOP
C1+
V+
C2-
C1-
C2+
V-
RIN
MAX221
FORCEON
EN
12
1
ROUT9
FORCEOFF
16
INVALID
10
GND
14
TIN
11
C2-
6
C2+
5
C1-
4
C1+
2
RIN 8
TOUT 13
V-
7
V+
3
V
CC
V
CC
C4
0.1µF
C3
0.1µF
0.1µF
15
C1
0.1µF
C2
0.1µF
C
BYPASS
+5V
TO POWER-
MANAGEMENT
UNIT
CAPACITORS MAY BE POLARIZED OR UNPOLARIZED.
5k
Typical Operating Circuit
19-1520; Rev 0; 8/99
PART
MAX221CUE
MAX221CAE
MAX221EUE -40°C to +85°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE PIN-PACKAGE
16 TSSOP
16 SSOP
16 TSSOP
AutoShutdown is a trademark of Maxim Integrated Products.
Pin Configuration
Ordering Information
MAX221EAE -40°C to +85°C 16 SSOP