19-1520; Rev 0; 8/99
+5V, 1µA, Single RS-232 Transceiver
with AutoShutdown
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.
Features
o
Single RS-232 Transceiver in a Small 16-Pin
TSSOP Package
o
1µA Supply Current
o
AutoShutdown Saves Power Without
Changes to BIOS
o
Guaranteed 250kbps Data Rate
MAX221
Ordering Information
PART
MAX221CUE
MAX221CAE
MAX221EUE
MAX221EAE
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 TSSOP
16 SSOP
16 TSSOP
16 SSOP
Applications
Maintenance/Diagnostic Ports
Industrial Systems
Telecommunications
Set-Top Boxes
+5V
Typical Operating Circuit
15
V
CC
V+
3
C3
0.1µF
Pin Configuration
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
C
BYPASS
C1
0.1µF
0.1µF
2 C1+
4 C1-
5
C2+
C2-
MAX221
V-
7
C4
0.1µF
C2
0.1µF
6
11 TIN
TOUT 13
MAX221
13 TOUT
12 FORCEON
11 TIN
10 INVALID
9
ROUT
1
EN
INVALID
10
TO POWER-
MANAGEMENT
UNIT
V
CC
9 ROUT
5k
RIN 8
TSSOP/SSOP
12
FORCEON
GND
14
FORCEOFF
16
CAPACITORS MAY BE POLARIZED OR UNPOLARIZED.
AutoShutdown is a trademark of Maxim Integrated Products.
________________________________________________________________
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
