19-1473; Rev 2; 8/04
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual
RS-232 Transceivers with Internal Capacitors
________________General Description
____________________________Features
The MAX3233E/MAX3235E are EIA/TIA-232 and V.28/V.24
communications interfaces with automatic shutdown/
wa ke -up fe a ture s , hig h d a ta -ra te c a p a b ilitie s , a nd
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.
♦ 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
♦ Latchup Free
♦ 1µA Supply Current
♦ AutoShutdown Plus—1997 EDN Magazine
Innovation of the Year
♦ Single-Supply Operation
All devices achieve a 1µA supply current using Maxim’s
re volutiona ry AutoShutd own Plus ™ fe a ture . The s e
d e vic e s a utoma tic a lly e nte r a low-p owe r s hutd own
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.
+3.0V to +3.6V (MAX3233E)
+4.5V to +5.5V (MAX3235E)
♦ 250kbps Guaranteed Data Rate
♦ 6V/µs Guaranteed Slew Rate
♦ Meets EIA/TIA-232 Specifications Down to 3.0V
(MAX3233E)
♦ Internal Charge-Pump Capacitors
Pin Configuration/
Functional Diagram
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.
1
20
R2OUT
R2IN
MAX3233E
MAX3235E
2
3
4
5
19
18
17
T2OUT
INVALID
________________________Applications
GND
V-
T2IN
T1IN
Subnotebook and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Handheld Equipment
Peripherals
16
C2-
FORCEON
R1OUT
6
7
8
9
15
14
13
C2+
CHARGE
PUMP
Embedded Systems
T1OUT
R1IN
C1-
_______________Ordering Information
C1+
PART
TEMP RANGE
PIN-PACKAGE
12
11
V
CC
V+
V+
MAX3233ECWP
MAX3233ECPP
MAX3233EEWP
MAX3233EEPP
0°C to +70°C
0°C to +70°C
20 SO
10
20 Plastic DIP
20 SO
FORCEOFF
-40°C to +85°C
-40°C to +85°C
20 Plastic DIP
SO/DIP
Ordering Information continued at end of data sheet.
AutoShutdown Plus is a trademark of Maxim Integrated Products, Inc.
Typical Operating Circuit appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.