19-0273; Rev 7; 1/07
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232
Transceivers Using Four 0.1µF External Capacitors
________________General Description
The MAX3222/MAX3232/MAX3237/MAX3241 trans-
ceivers have a proprietary low-dropout transmitter out-
put stage enabling true RS-232 performance from a
3.0V to 5.5V supply with a dual charge pump. The
devices require only four small 0.1µF external charge-
pump capacitors. The MAX3222, MAX3232, and
MAX3241 are guaranteed to run at data rates of
120kbps while maintaining RS-232 output levels. The
MAX3237 is guaranteed to run at data rates of 250kbps
in the normal operating mode and 1Mbps in the
MegaBaud™ operating mode, while maintaining RS-232
output levels.
The MAX3222/MAX3232 have 2 receivers and 2
drivers. The MAX3222 features a 1µA shutdown mode
that reduces power consumption and extends battery
life in portable systems. Its receivers remain active in
shutdown mode, allowing external devices such as
modems to be monitored using only 1µA supply cur-
rent. The MAX3222 and MAX3232 are pin, package,
and functionally compatible with the industry-standard
MAX242 and MAX232, respectively.
The MAX3241 is a complete serial port (3 drivers/
5 receivers) designed for notebook and subnotebook
computers. The MAX3237 (5 drivers/3 receivers) is ideal
for fast modem applications. Both these devices feature
a shutdown mode in which all receivers can remain
active while using only 1µA supply current. Receivers R1
(MAX3237/MAX3241) and R2 (MAX3241) have extra out-
puts in addition to their standard outputs. These extra
outputs are always active, allowing external devices
such as a modem to be monitored without forward bias-
ing the protection diodes in circuitry that may have V
CC
completely removed.
The MAX3222, MAX3232, and MAX3241 are available
in space-saving TSSOP and SSOP packages.
__Next Generation Device Features
♦
For Smaller Packaging:
MAX3228E/MAX3229E: +2.5V to +5.5V RS-232
Transceivers in UCSP™
♦
For Integrated ESD Protection:
MAX3222E/MAX3232E/MAX3237E/MAX3241E*/
MAX3246E: ±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps, True RS-232
Transceivers
♦
For Low-Voltage or Data Cable Applications:
MAX3380E/MAX3381E: +2.35V to +5.5V, 1μA,
2Tx/2Rx RS-232 Transceivers with ±15kV
ESD-Protected I/O and Logic Pins
MAX3222/MAX3232/MAX3237/MAX3241*
_______________Ordering Information
PART
MAX3222CUP+
MAX3222CAP+
MAX3222CWN+
MAX3222CPN+
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
20 TSSOP
20 SSOP
18 SO
18 Plastic Dip
PKG
CODE
U20+2
A20+1
W18+1
P18+5
+
Denotes lead-free package.
Ordering Information continued at end of data sheet.
_________________Pin Configurations
TOP VIEW
EN 1
C1+ 2
V+ 3
C1- 4
C2+ 5
C2-
6
7
8
9
+
18 SHDN
17 V
CC
16 GND
________________________Applications
Notebook, Subnotebook, and Palmtop Computers
High-Speed Modems
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
Typical Operating Circuits appear at end of data sheet.
MAX3222
MAX3222
15 T1OUT
14 R1IN
13 R1OUT
12 T1IN
11 T2IN
10 R2OUT
V-
T2OUT
R2IN
DIP/SO
Pin Configurations continued at end of data sheet.
MegaBaud and UCSP are trademarks of Maxim Integrated Products, Inc.
*Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending.
________________________________________________________________
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.
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232
Transceivers Using Four 0.1µF External Capacitors
MAX3222/MAX3232/MAX3237/MAX3241
ABSOLUTE MAXIMUM RATINGS
V
CC
...........................................................................-0.3V to +6V
V+ (Note 1) ...............................................................-0.3V to +7V
V- (Note 1) ................................................................+0.3V to -7V
V+ + V- (Note 1)...................................................................+13V
Input Voltages
T_IN,
SHDN, EN
...................................................-0.3V to +6V
MBAUD...................................................-0.3V to (V
CC
+ 0.3V)
R_IN .................................................................................±25V
Output Voltages
T_OUT...........................................................................±13.2V
R_OUT ....................................................-0.3V to (V
CC
+ 0.3V)
Short-Circuit Duration
T_OUT ....................................................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TSSOP (derate 6.7mW/°C above +70°C).............533mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ....696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)........762mW
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW
18-Pin SO (derate 9.52mW/°C above +70°C)..............762mW
18-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ..889mW
20-Pin SSOP (derate 7.00mW/°C above +70°C) .........559mW
20-Pin TSSOP (derate 8.0mW/°C above +70°C).............640mW
28-Pin TSSOP (derate 8.7mW/°C above +70°C).............696mW
28-Pin SSOP (derate 9.52mW/°C above +70°C) .........762mW
28-Pin SO (derate 12.50mW/°C above +70°C) .....................1W
Operating Temperature Ranges
MAX32_ _C_ _.....................................................0°C to +70°C
MAX32_ _E_ _ .................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DC CHARACTERISTICS
V
CC
Power-Supply Current
Shutdown Supply Current
Input Logic Threshold Low
(Note 3)
Input Logic Threshold High
(Note 3)
Input Leakage Current
Output Leakage Current
Output Voltage Low
Output Voltage High
RECEIVER INPUTS
Input Voltage Range
Input Threshold Low
Input Threshold High
T
A
= +25°C
T
A
= +25°C
V
CC
= 5.0V
V
CC
= 3.3V
V
CC
= 5.0V
V
CC
= 3.3V
V
CC
= 5.0V
-25
0.6
0.8
1.2
1.5
1.5
1.8
2.4
2.4
25
V
V
V
No load, V
CC
= 3.3V or 5.0V,
T
A
= +25°C
SHDN
= GND, T
A
= +25°C
MAX3222/MAX3232/
MAX3241
MAX3237
0.3
0.5
1.0
1.0
2.0
10
µA
mA
CONDITIONS
MIN
TYP
MAX
UNITS
LOGIC INPUTS AND RECEIVER OUTPUTS
T_IN,
EN, SHDN,
MBAUD
V
CC
= 3.3V
V
CC
= 5.0V
T_IN,
EN, SHDN,
MBAUD
Receivers disabled
I
OUT
= 1.6mA
I
OUT
= -1.0mA
V
CC
- 0.6
V
CC
- 0.1
2.0
2.4
±0.01
±0.05
±1.0
±10
0.4
0.8
V
V
µA
µA
V
V
2
_______________________________________________________________________________________
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232
Transceivers Using Four 0.1µF External Capacitors
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Input Hysteresis
Input Resistance
TRANSMITTER OUTPUTS
Output Voltage Swing
Output Resistance
Output Short-Circuit Current
Output Leakage Current
V
OUT
= ±12V, V
CC
= 0V or 3V to 5.5V, transmitters
disabled
All transmitter outputs loaded with 3kΩ to ground
V
CC
= V+ = V- = 0V, V
OUT
= ±2V
±5.0
300
±5.4
10M
±35
±60
±25
V
Ω
mA
µA
T
A
= +25°C
3
CONDITIONS
MIN
TYP
0.3
5
7
MAX
UNITS
V
kΩ
MAX3222/MAX3232/MAX3237/MAX3241
MOUSE DRIVEABILITY (MAX3241)
Transmitter Output Voltage
T1IN = T2IN = GND, T3IN = V
CC
,
T3OUT loaded with 3kΩ to GND,
T1OUT and T2OUT loaded with 2.5mA each
±5.0
V
TIMING CHARACTERISTICS—MAX3222/MAX3232/MAX3241
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Maximum Data Rate
Receiver Propagation Delay
Receiver Output Enable Time
Transmitter Skew
Receiver Skew
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching
R_IN to R_OUT, C
L
= 150pF
Normal operation
t
PHL
t
PLH
MIN
120
TYP
235
0.3
0.3
200
200
300
300
C
L
= 150pF to
1000pF
C
L
= 150pF to
2500pF
6
4
30
V/µs
30
MAX
UNITS
kbps
µs
ns
ns
ns
ns
Receiver Output Disable Time Normal operation
|
t
PHL
- t
PLH
|
|
t
PHL
- t
PLH
|
V
CC
= 3.3V, R
L
= 3kΩ to 7kΩ,
+3V to -3V or -3V to +3V,
T
A
= +25°C, one transmitter
switching
Transition-Region Slew Rate
_______________________________________________________________________________________
3
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232
Transceivers Using Four 0.1µF External Capacitors
MAX3222/MAX3232/MAX3237/MAX3241
TIMING CHARACTERISTICS—MAX3237
(V
CC
= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
CONDITIONS
R
L
= 3kΩ, C
L
= 1000pF, one transmitter switching,
MBAUD = GND
Maximum Data Rate
V
CC
= 3.0V to 4.5V, R
L
= 3kΩ, C
L
= 250pF,
one transmitter switching, MBAUD = V
CC
V
CC
= 4.5V to 5.5V, R
L
= 3kΩ, C
L
= 1000pF,
one transmitter switching, MBAUD = V
CC
Receiver Propagation Delay
Receiver Output Enable Time
R_IN to R_OUT, C
L
= 150pF
Normal operation
t
PHL
t
PLH
MIN
250
1000
1000
0.15
0.15
200
200
100
25
50
C
L
= 150pF
to 1000pF
MBAUD =
GND
MBAUD =
V
CC
6
24
4
30
150
30
V/µs
µs
ns
ns
ns
ns
ns
kbps
TYP
MAX
UNITS
Receiver Output Disable Time Normal operation
Transmitter Skew
Receiver Skew
|
t
PHL
- t
PLH
|
, MBAUD = GND
|
t
PHL
- t
PLH
|
, MBAUD = V
CC
|
t
PHL
- t
PLH
|
Transition-Region Slew Rate
V
CC
= 3.3V, R
L
= 3Ω to 7kΩ,
+3V to -3V or -3V to +3V,
T
A
= +25°C
C
L
= 150pF to 2500pF,
MBAUD = GND
Note 2:
MAX3222/MAX3232/MAX3241: C1–C4 = 0.1µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.
MAX3237: C1–C4 = 0.1µF tested at 3.3V ±5%; C1–C4 = 0.22µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested
at 5.0V ±10%.
Note 3:
Transmitter input hysteresis is typically 250mV.
__________________________________________Typical Operating Characteristics
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T
A
= +25°C, unless otherwise noted.)
MAX3222/MAX3232
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3222-01
MAX3222/MAX3232
SLEW RATE
vs. LOAD CAPACITANCE
20
18
SLEW RATE (V/µs)
16
14
12
10
8
6
4
2
0
5000
150
1000
2000
3000
4000
5000
5
0
+SLEW
-SLEW
SUPPLY CURRENT (mA)
30
25
FOR DATA RATES UP TO 235kbps
MAX3222-02
MAX3222/MAX3232
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA
35
235kbps
MAX3222-03
6
5
TRANSMITTER OUTPUT VOLTAGE (V)
4
3
2
1
0
-1
-2
-3
-4
-5
-6
0
1000
2000
3000
22
40
V
OUT
+
120kbps
20
15
20kbps
10
V
OUT
-
4000
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
4
_______________________________________________________________________________________
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232
Transceivers Using Four 0.1µF External Capacitors
_____________________________Typical Operating Characteristics (continued)
(V
CC
= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T
A
= +25°C, unless otherwise noted.)
MAX3241
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3222-04
MAX3222/MAX3232/MAX3237/MAX3241
MAX3241
SLEW RATE
vs. LOAD CAPACITANCE
MAX3222-05
MAX3241
SUPPLY CURRENT vs. LOAD
CAPACITANCE WHEN TRANSMITTING DATA
40
SUPPLY CURRENT (mA)
35
30
25
20
15
10
5
5000
0
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
20kbps
120kbps
235kbps
MAX3222-06
7.5
V
OUT
+
TRANSMITTER OUTPUT VOLTAGE (V)
5.0
2.5
0
-2.5
-5.0
-7.5
0
1000
2000
3000
4000
V
OUT
-
24
22
20
SLEW RATE (V/µs)
18
16
14
12
10
8
6
4
+SLEW
ALL OUTPUTS LOADED WITH 3kΩ +C
L
0.1µF CHARGE-PUMP CAPACITORS
FOR ALL DATA RATES UP TO 235kbps
0
1000
2000
3000
4000
45
1 TRANSMITTER AT 235kbps
2 TRANSMITTERS AT 30kbps
-SLEW
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3237
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = GND)
MAX3222-07
MAX3237
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = V
CC
)
1Mbps
TRANSMITTER OUTPUT VOLTAGE (V)
5.0
2.5
0
-2.5
-5.0
-7.5
2Mbps
1.5Mbps
2
1Mbps
0
0
500
1000
1500
2000
0
LOAD CAPACITANCE (pF)
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
L
LOAD, EACH OUTPUT
V
CC
= 3.3V
2Mbps
1.5Mbps
SLEW RATE (V/µs)
8
6
4
MAX3222-08
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = GND)
MAX3222-09
7.5
TRANSMITTER OUTPUT VOLTAGE (V)
5.0
2.5
0
-2.5
-5.0
-7.5
0
1000
2000
3000
4000
7.5
12
10
+SLEW
-SLEW
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C
L
LOADS
V
CC
= 3.3V
1 TRANSMITTER AT 240kbps
4 TRANSMITTERS AT 15kbps
3kΩ + C
L
LOADS
V
CC
= 3.3V
1000
2000
3000
4000
5000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
MAX3237
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = V
CC
)
MAX3222-10
MAX3237
SUPPLY CURRENT vs.
LOAD CAPACITANCE (MBAUD = GND)
MAX3222-11
MAX3237
SKEW vs. LOAD CAPACITANCE
(t
PLH
- t
PHL
)
60
50
40
1 TRANSMITTER AT 512kbps
4 TRANSMITTERS AT 32kbps
3kΩ + C
L
LOADS
V
CC
= 3.3V
MBAUD = V
CC
MAX
AVERAGE; 10 PARTS
SKEW (ns)
MAX3222-12
70
60
SLEW RATE (V/µs)
50
40
30
20
10
0
0
-SLEW, 1Mbps
+SLEW, 1Mbps
-SLEW, 2Mbps
+SLEW, 2Mbps
60
50
SUPPLY CURRENT (mA)
40
30
20kbps
20
10
0
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
L
LOADS
V
CC
= 3.3V
0
1000
2000
3000
4000
240kbps
120kbps
70
30
20
10
0
5000
0
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + C
L
LOAD EACH OUTPUT
V
CC
= 3.3V
500
1000
1500
2000
MIN
500
1000
1500
2000
2500
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
_______________________________________________________________________________________
5
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