19-2140; Rev 1; 5/04
+2.5V to +5.5V RS-232 Transceivers
in UCSP
General Description
Features
The MAX3228/MAX3229 are +2.5V to +5.5V powered
EIA/TIA-232 and V.28/V.24 communications interfaces
with low power requirements, and high data-rate capa-
bilities, in a chip-scale package (UCSP™).
♦ 6 ♦ 5 Chip-Scale Packaging (UCSP)
♦ 1µA Low-Power AutoShutdown
♦ 250kbps Guaranteed Data Rate
The MAX3228/MAX3229 achieve a 1µA supply current
with Maxim’s AutoShutdown™ feature. They save
power without changes to existing BIOS or operating
systems by entering low-power shutdown mode when
the RS-232 cable is disconnected, or when the trans-
mitters of the connected peripherals are off.
♦ Meets EIA/TIA-232 Specifications Down to +3.1V
♦ RS-232 Compatible to +2.5V Allows Operation
from Single Li+ Cell
♦ Small 0.1µF Capacitors
♦ Configurable Logic Levels
The transceivers have a proprietary low-dropout trans-
mitter output stage, delivering RS-232 compliant perfor-
mance from a +3.1V to +5.5V supply, and RS-232
compatible performance with a supply voltage as low
as +2.5V. The dual charge pump requires only four
small 0.1µF capacitors for operation from a +3.0V sup-
ply. Each device is guaranteed to run at data rates of
250kbps while maintaining RS-232 output levels.
Ordering Information
PIN-
PACKAGE
PART
TEMP RANGE
MAX3228EBV
MAX3229EBV
-40°C to +85°C
-40°C to +85°C
6 x 5 UCSP*
6 x 5 UCSP*
The MAX3228/MAX3229 offer a separate power-supply
input for the logic interface, allowing configurable logic
levels on the receiver outputs and transmitter inputs.
*Requires solder temperature profile described in the Absolute
Maximum Ratings section.
*UCSP reliability is integrally linked to the user’s assembly
methods, circuit board material, and environment. Refer to the
UCSP Reliabilitly Notice in the UCSP Reliability section of this
data sheet for more information.
Operating over a +1.65V to V
range, V provides the
L
CC
MAX3228/MAX3229 compatibility with multiple logic
families.
The MAX3229 contains one receiver and one transmit-
ter. The MAX3228 contains two receivers and two
transmitters. The MAX3228/MAX3229 are available in
tiny chip-scale packaging and are specified across the
extended industrial temperature range of -40°C to
+85°C.
Typical Operating Circuits
2.5V TO 5.5V 1.65V TO 5.5V
0.1µF
C
0.1µF
BYPASS
A1
A5
V
CC
V
C1
B1
A4
L
C1+
V+
C3
C1
0.1µF
0.1µF
Applications
D1
A2
C1-
C2+
MAX3228
V-
Personal Digital Assistants
Cell Phone Data Lump Cables
Set-Top Boxes
C2
C4
0.1µF
0.1µF
A3
V
L
C2-
T1OUT
A6 T1IN
E3
RS-232
OUTPUTS
TTL/CMOS
INPUTS
V
L
B6
T2IN
T2OUT E4
Hand-Held Devices
Cell Phones
V
L
R1IN
D6 R1OUT
E6
5kΩ
TTL/CMOS
OUTPUTS
RS-232
INPUTS
V
L
Typical Operating Circuits continued at end of data sheet.
Pin Configurations appear at end of data sheet.
C6
R2OUT
R2IN E5
5kΩ
V
L
V
L
TO POWER-
MANAGEMENT
UNIT
UCSP is a trademark of Maxim Integrated Products, Inc.
E2
INVALID
20µA
20µA
FORCEON
AutoShutdown is a trademark of Maxim Integrated Products, Inc.
FORCEOFF C5
B5
V
L
GND
E1
________________________________________________________________ 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.