19-1473; Rev 0; 4/99
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual
RS-232 Transceivers with Internal Capacitors
________________General Description
The MAX3233E/MAX3235E are EIA/TIA-232 and V.28/V.24
communications interfaces with automatic shutdown/
wake-up features, high data-rate capabilities, and
enhanced electrostatic discharge (ESD) protection. All
transmitter outputs and receiver inputs are protected to
±15kV using IEC 1000-4-2 Air-Gap Discharge, to ±8kV
using IEC 1000-4-2 Contact Discharge, and to ±15kV
using the Human Body Model. The MAX3233E operates
from a +3.3V supply; the MAX3235E operates from +5.0V.
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 following two conditions occur: either
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 receiver input.
AutoShutdown Plus saves power without changes to
the existing BIOS or operating system.
The MAX3233E/MAX3235E have internal dual charge
pumps requiring no external capacitors. Both trans-
ceivers have a proprietary low-dropout transmitter out-
put stage that enables true RS-232 performance from a
+3.0V to +3.6V supply for the MAX3233E or a +4.5V to
+5.5V supply for the MAX3235E. These devices are
guaranteed to operate up to 250kbps. Both are avail-
able in space-saving 20-pin wide SO or plastic DIP
packages.
____________________________Features
o
ESD Protection for RS-232 I/O Pins
±15kV—Human Body Model
±8kV—IEC 1000-4-2, Contact Discharge
±15kV—IEC 1000-4-2, Air-Gap Discharge
o
Latchup Free
o
1µA Supply Current
o
AutoShutdown Plus—1997 EDN Magazine
Innovation of the Year
o
Single-Supply Operation
+3.0V to +3.6V (MAX3233E)
+4.5V to +5.5V (MAX3235E)
o
250kbps Guaranteed Data Rate
o
6V/µs Guaranteed Slew Rate
o
Meets EIA/TIA-232 Specifications Down to 3.0V
(MAX3233E)
o
Internal Charge-Pump Capacitors
MAX3233E
†
/MAX3235E
†
Pin Configuration/
Functional Diagram
R2OUT
1
2
3
4
5
6
7
8
9
10
20
MAX3233E
MAX3235E
R2IN
INVALID
T2IN
T1IN
FORCEON
R1OUT
T1OUT
19
18
17
16
15
14
13
12
11
T2OUT
GND
V-
C2-
C2+
C1-
C1+
V+
V+
________________________Applications
Subnotebook and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Embedded Systems
CHARGE
PUMP
_______________Ordering Information
R1IN
PART
MAX3233ECWP
MAX3233ECPP
MAX3233EEWP
MAX3233EEPP
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
20 SO
20 Plastic DIP
20 SO
20 Plastic DIP
V
CC
FORCEOFF
Ordering Information continued at end of data sheet.
AutoShutdown Plus is a trademark of Maxim Integrated Products.
†
Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577;
SO/DIP
4,797,899; 4,809,152; 4,897,774; 4,999,761; 5,649,210; and other
patents pending.
Typical Operating Circuit appears at end of data sheet.
1
________________________________________________________________
Maxim Integrated Products
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 ]
