General Description
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E +3.0V-powered EIA/TIA-232 and V.28/V.24
communications interface devices feature low power
consumption, high data-rate capabilities, and enhanced
electrostatic-discharge (ESD) protection. The enhanced
ESD structure protects all transmitter outputs and receiver
inputs to ±15kV using IEC 1000-4-2 Air-Gap Discharge,
±8kV using IEC 1000-4-2 Contact Discharge (±9kV for
MAX3246E), and ±15kV using the Human Body Model.
The logic and receiver I/O pins of the MAX3237E are pro-
tected to the above standards, while the transmitter output
pins are protected to ±15kV using the Human Body Model.
A proprietary low-dropout transmitter output stage deliv-
ers true RS-232 performance from a +3.0V to +5.5V
power supply, using an internal dual charge pump. The
charge pump requires only four small 0.1μF capacitors
for operation from a +3.3V supply. Each device guaran-
tees operation at data rates of 250kbps while maintaining
RS-232 output levels. The MAX3237E guarantees opera-
tion at 250kbps in the normal operating mode and 1Mbps
in the MegaBaud™ operating mode, while maintaining
RS-232-compliant output levels.
The MAX3222E/MAX3232E have two receivers and two
transmitters. The MAX3222E features a 1μA shutdown
mode that reduces power consumption in battery-pow-
ered portable systems. The MAX3222E receivers remain
active in shutdown mode, allowing monitoring of external
devices while consuming only 1μA of supply current. The
MAX3222E and MAX3232E are pin, package, and func-
tionally compatible with the industry-standard MAX242
and MAX232, respectively.
The MAX3241E/MAX3246E are complete serial ports
(three drivers/five receivers) designed for notebook and
subnotebook computers. The MAX3237E (five drivers/
three receivers) is ideal for peripheral applications that
require fast data transfer. These devices feature a shut-
down mode in which all receivers remain active, while
consuming only 1μA (MAX3241E/MAX3246E) or 10nA
(MAX3237E).
The MAX3222E, MAX3232E, and MAX3241E are avail-
able in space-saving SO, SSOP, TQFN and TSSOP pack-
ages. The MAX3237E is offered in an SSOP package.
The MAX3246E is offered in the ultra-small 6 x 6 UCSP™
package.
Next-Generation Device Features
For Space-Constrained Applications
MAX3228E/MAX3229E: ±15kV ESD-Protected,
+2.5V to +5.5V, RS-232 Transceivers in UCSP
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
Applications
Battery-Powered Equipment
Cell Phones Smart Phones
Cell-Phone Data Cables
Notebook, Subnotebook, and Palmtop Computers
Printers
xDSL Modems
19-1298; Rev 13; 12/18
Ordering Information continued at end of data sheet.
Pin Configurations, Selector Guide, and Typical Operating
Circuits appear at end of data sheet.
MegaBaud and UCSP are trademarks of Maxim Integrated
Products, Inc.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*Dice are tested at TA = +25°C, DC parameters only.
**EP = Exposed pad.
/V denotes an automotive qualified part.
PART TEMP RANGE PIN-PACKAGE
MAX3222ECTP+ 0°C to +70°C 20 TQFN-EP**
(5mm x 5mm)
MAX3222ECUP+ 0°C to +70°C 20 TSSOP
MAX3222ECAP+ 0°C to +70°C 20 SSOP
MAX3222ECWN+ 0°C to +70°C 18 Wide SO
MAX3222ECPN+ 0°C to +70°C 18 Plastic DIP
MAX3222EC/D+ 0°C to +70°C Dice*
MAX3222EETP+ -40°C to +85°C 20 TQFN-EP**
(5mm x 5mm)
MAX3222EEUP/V+ -40°C to +85°C 20 TSSOP
MAX3222EEUP+ -40°C to +85°C 20 TSSOP
MAX3222EEAP+ -40°C to +85°C 20 SSOP
MAX3222EEWN+ -40°C to +85°C 18 Wide SO
MAX3222EEPN+ -40°C to +85°C 18 Plastic DIP
MAX3232ECAE+ 0°C to +70°C 16 SSOP
MAX3232ECWE+ 0°C to +70°C 16 Wide SO
MAX3232ECPE+ 0°C to +70°C 16 Plastic DIP
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Ordering Information
Click here for production status of specic part numbers.
EVALUATION KIT AVAILABLE
VCC to GND ............................................................-0.3V to +6V
V+ to GND (Note 1) ................................................. -0.3V to +7V
V- to GND (Note 1) .................................................. +0.3V to -7V
V+ + |V-| (Note 1) ................................................................+13V
Input Voltages
T_IN, EN, SHDN, MBAUD to GND .....................-0.3V to +6V
R_IN to GND ...................................................................±25V
Output Voltages
T_OUT to GND .............................................................±13.2V
R_OUT, R_OUTB
(MAX3237E/MAX3241E) ...................... -0.3V to (VCC + 0.3V)
Short-Circuit Duration, T_OUT to GND ..................... Continuous
Continuous Power Dissipation (TA = +70°C)
16-Pin SSOP (derate 7.14mW/°C above +70°C) ........571mW
16-Pin TSSOP (derate 9.4mW/°C above +70°C) ..... 754.7mW
16-Pin TQFN (derate 20.8mW/°C above +70°C) ...1666.7mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C) ...762mW
18-Pin Wide SO (derate 9.52mW/°C above +70°C) ...762mW
18-Pin PDIP (derate 11.11mW/°C above +70°C) ........889mW
20-Pin TQFN (derate 21.3mW/°C above +70°C) ......1702mW
20-Pin TSSOP (derate 10.9mW/°C above +70°C) ...... 879mW
20-Pin SSOP (derate 8.00mW/°C above +70°C) ........640mW
28-Pin SSOP (derate 9.52mW/°C above +70°C) ........762mW
28-Pin Wide SO (derate 12.50mW/°C above +70°C) ........1W
28-Pin TSSOP (derate 12.8mW/°C above +70°C) .... 1026mW
32-Pin TQFN (derate 33.3mW/°C above +70°C) ......2666mW
6 x 6 UCSP (derate 12.6mW/°C above +70°C) ........1010mW
Operating Temperature Ranges
MAX32_ _EC_ _ ................................................. 0°C to +70°C
MAX32_ _EE_ _ ............................................. -40°C to +85°C
Storage Temperature Range ............................ -65°C to +150°C
Lead Temperature (soldering, 10s) ................................. +300°C
Soldering Temperature (reflow) ....................................... +260°C
Bump Reflow Temperature (Note 2)
Infrared, 15s ................................................................+200°C
Vapor Phase, 20s ........................................................ +215°C
(VCC = +3V to +5.5V, C1–C4 = 0.1μF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 3, 4)
Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
Note 2: This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile the device
can be exposed to during board-level solder attach and rework. This limit permits only the use of the solder profiles recom-
mended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and convection reflow.
Preheating is required. Hand or wave soldering is not allowed.
PARAMETER CONDITIONS MIN TYP MAX UNITS
DC CHARACTERISTICS (VCC = +3.3V or +5V, TA = +25°C)
Supply Current SHDN = VCC, no load
MAX3222E, MAX3232E,
MAX3241E, MAX3246E 0.3 1 mA
MAX3237E 0.5 2.0
Shutdown Supply Current
SHDN = GND 1 10 µA
SHDN = R_IN = GND, T_IN = GND or VCC (MAX3237E) 10 300 nA
LOGIC INPUTS
Input Logic Low T_IN, EN, SHDN, MBAUD 0.8 V
Input Logic High T_IN, EN, SHDN, MBAUD VCC = +3.3V 2.0 V
VCC = +5.0V 2.4
Transmitter Input Hysteresis 0.5 V
Input Leakage Current T_IN, EN, SHDN MAX3222E, MAX3232E,
MAX3241E, MAX3246E ±0.01 ±1 µA
T_IN, SHDN, MBAUD MAX3237E (Note 5) 9 18
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MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Absolute Maximum Ratings
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
(VCC = +3V to +5.5V, C1–C4 = 0.1μF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 3, 4)
PARAMETER CONDITIONS MIN TYP MAX UNITS
RECEIVER OUTPUTS
Output Leakage Current R_OUT (MAX3222E/MAX3237E/MAX3241E/
MAX3246E), EN = VCC, receivers disabled ±0.05 ±10 µA
Output-Voltage Low IOUT = 1.6mA (MAX3222E/MAX3232E/MAX3241E/
MAX3246E), IOUT = 1.0mA (MAX3237E) 0.4 V
Output-Voltage High IOUT = -1.0mA VCC -
0.6
VCC -
0.1 V
RECEIVER INPUTS
Input Voltage Range -25 +25 V
Input Threshold Low TA = +25°C VCC = +3.3V 0.6 1.1 V
VCC = +5.0V 0.8 1.5
Input Threshold High TA = +25°C VCC = +3.3V 1.5 2.4 V
VCC = +5.0V 2.0 2.4
Input Hysteresis 0.5 V
Input Resistance TA = +25°C 3 5 7
TRANSMITTER OUTPUTS
Output Voltage Swing All transmitter outputs loaded with 3kΩ to ground (Note 6) ±5 ±5.4 V
Output Resistance VCC = 0V, transmitter output = ±2V 300 50k Ω
Output Short-Circuit Current ±60 mA
Output Leakage Current VCC = 0V or +3.0V to +5.5V, VOUT = ±12V, transmitters
disabled (MAX3222E/MAX3232E/MAX3241E/MAX3246E) ±25 µA
MOUSE DRIVABILITY (MAX3241E)
Transmitter Output Voltage T1IN = T2IN = GND, T3IN = VCC, T3OUT loaded with 3kΩ
to GND, T1OUT and T2OUT loaded with 2.5mA each ±5 V
ESD PROTECTION
R_IN, T_OUT
Human Body Model ±15
kV
IEC 1000-4-2 Air-Gap Discharge (except MAX3237E) ±15
IEC 1000-4-2 Contact Discharge (except MAX3237E) ±8
IEC 1000-4-2 Contact Discharge (MAX3246E only) ±9
T_IN, R_IN, R_OUT, EN, SHDN,
MBAUD MAX3237E
Human Body Model ±15
kVIEC 1000-4-2 Air-Gap Discharge ±15
IEC 1000-4-2 Contact Discharge ±8
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MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Electrical Characteristics (continued)
(VCC = +3V to +5.5V, C1–C4 = 0.1μF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 3, 4)
(VCC = +3V to +5.5V, C1–C4 = 0.1μF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 3)
Note 3: MAX3222E/MAX3232E/MAX3241E: C1–C4 = 0.1μF tested at +3.3V ±10%; C1 = 0.047μF, C2, C3, C4 = 0.33μF tested at
+5.0V ±10%. MAX3237E: C1–C4 = 0.1μF tested at +3.3V ±5%, C1–C4 = 0.22μF tested at +3.3V ±10%; C1 = 0.047μF, C2,
C3, C4 = 0.33μF tested at +5.0V ±10%. MAX3246E: C1-C4 = 0.22μF tested at +3.3V ±10%; C1 = 0.22μF, C2, C3, C4 =
0.54μF tested at +5.0V ±10%.
Note 4: MAX3246E devices are production tested at +25°C. All limits are guaranteed by design over the operating temperature
range.
Note 5: The MAX3237E logic inputs have an active positive feedback resistor. The input current goes to zero when the inputs are at
the supply rails.
Note 6: MAX3241EEUI is specified at TA = +25°C.
Transmitter skew is measured at the transmitter zero crosspoints.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Maximum Data Rate
RL = 3kΩ,
CL = 1000pF,
one transmitter
switching
TA = TMIN to TMAX
(MAX3222E/MAX3232E/
MAX3241E) (Note 6) 250 kbps
TA = +25°C (MAX3246E) 250
Receiver Propagation Delay tPHL Receiver input to receiver output,
CL = 150pF
0.15 µs
tPLH 0.15
Receiver Output Enable Time Normal operation (except MAX3232E) 200 ns
Receiver Output Disable Time Normal operation (except MAX3232E) 200 ns
Transmitter Skew |tPHL - tPLH|(Note 7) 100 ns
Receiver Skew |tPHL - tPLH| 50 ns
Transition-Region Slew Rate
VCC = +3.3V, TA = +25°C,
RL = 3kΩ to 7kΩ, measured
from +3.0V to -3.0V or -3.0V to
+3.0V, one transmitter switching
CL = 150pF
to 1000pF 6 30 V/µs
PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Data Rate
RL = 3kΩ, CL = 1000pF, one transmitter switching,
MBAUD = GND 250
kbps
VCC = +3.0V to +4.5V, RL = 3kΩ, CL = 250pF,
one transmitter switching, MBAUD = VCC 1000
VCC = +4.5V to +5.5V, RL = 3kΩ, CL = 1000pF,
one transmitter switching, MBAUD = VCC 1000
Receiver Propagation Delay R_IN to R_OUT, CL = 150pF tPHL 0.15 µs
tPLH 0.15
Receiver Output Enable Time Normal operation 2.6 µs
Receiver Output Disable Time Normal operation 2.4 µs
Transmitter Skew (Note 7) |tPHL - tPLH|, MBAUD = GND 100 ns
|tPHL - tPLH|, MBAUD = VCC
Receiver Skew |tPHL - tPLH| 50 ns
Transition-Region Slew Rate
VCC = +3.3V,
RL = 3kΩ to 7kΩ,
+3.0V to -3.0V or
-3.0V to +3.0V,
TA = +25°C
CL = 150pF to
1000pF
MBAUD = GND 6 30
V/µs
MBAUD = VCC 24 150
CL = 150pF to 2500pF,
MBAUD = GND 4 30
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MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Timing Characteristics—MAX3222E/MAX3232E/MAX3241E/MAX3246E
Timing Characteristics—MAX3237E
(VCC = +3.3V, 250kbps data rate, 0.1μF capacitors, all transmitters loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)
0
25
20
15
5
10
35
30
40
45
0 20001000 3000 4000 5000
MAX3222E/MAX3232E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3237E toc03
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
120kbps
20kbps
T1 TRANSMITTING AT 250kbps
T2 TRANSMITTING AT 15.6kbps
0
30
20
10
40
50
60
0 20001000 3000 4000 5000
MAX3241E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3237E toc06
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
120kbps
20kbps
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
-7.5
-5.0
-2.5
0
2.5
5.0
7.5
0
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = VCC)
MAX3237E toc08
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
500 1000 1500 2000
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3k + CL LOAD, EACH OUTPUT
2Mbps 1.5Mbps
1Mbps
2Mbps
1Mbps
1.5Mbps
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
0 1000 2000 3000 4000 5000
MAX3222E/MAX3232E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3237E toc01
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
T1 TRANSMITTING AT 250kbps
T2 TRANSMITTING AT 15.6kbps
VOUT+
VOUT-
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
0 1000 2000 3000 4000 5000
MAX3241E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3237E to04
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
VOUT+
VOUT-
-6
-4
-2
0
2
4
6
0
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = GND)
MAX3237E toc07
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
1000 1500500 2000 2500 3000
FOR DATA RATES UP TO 250kbps
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3k + CL
5
3
1
-1
-3
-5
V
OUT+
VOUT-
0
6
2
4
10
8
14
12
16
0 1000 2000 3000 4000 5000
MAX3222E/MAX3232E
SLEW RATE vs. LOAD CAPACITANCE
MAX3237E toc02
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
+SLEW
FOR DATA RATES UP TO 250kbps
-SLEW
0
4
2
8
6
12
10
14
0 1000 2000 3000 4000 5000
MAX3241E
SLEW RATE vs. LOAD CAPACITANCE
MAX3237E toc05
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
-6
-2
-4
2
0
4
6
-5
-3
1
-1
3
5
0 1000 1500500 2000 2500 3000
MAX3246E toc07A
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
VOUT-
VOUT+
FOR DATA RATES UP TO 250kbps
1 TRANSMITTER 250kbps
4 TRANSMITTERS 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3k + CL
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
Maxim Integrated
5
www.maximintegrated.com
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Typical Operating Characteristics
(VCC = +3.3V, 250kbps data rate, 0.1μF capacitors, all transmitters loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)
0
10
20
30
40
50
0
MAX3237E
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA (MBAUD = GND)
MAX3237E toc11
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
1000 1500500 2000 2500 3000
250kbps
120kbps
20kbps
1 TRANSMITTER AT 20kbps, 120kbps, 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3k + CL
0
10
20
30
40
50
2.0
MAX3237E SUPPLY CURRENT
vs. SUPPLY VOLTAGE (MBAUD = GND)
MAX3237E toc14
SUPPLY VOLTAGE (V)
3.0 3.52.5 4.0 4.5 5.0
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3k AND 1000pF
0
10
20
30
40
50
60
0
MAX3246E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCE
MAX3237E toc17
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
1000 2000 3000 4000 5000
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
55
45
35
25
15
5
250kbps
120kbps
20kbps
0
2
4
6
8
10
12
0
MAX3237E
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = GND)
MAX3237E toc09
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
1000 1500500 2000 2500 3000
SR+
SR-
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3k + CL
0
20
60
40
80
100
0
MAX3237E
TRANSMITTER SKEW vs. LOAD
CAPACITANCE (MBAUD = VCC)
MAX3237E toc12
LOAD CAPACITANCE (pF)
1000 1500500 2000
TRANSMITTER SKEW (ns)
|tPLH - tPHL|
1 TRANSMITTER AT 500kbps
4 TRANSMITTERS AT 1/16 DATA RATE
ALL TRANSMITTERS LOADED
WITH 3k + CL
MAX3246E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
MAX3237E toc15
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
400030001000 2000
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
-6
0 5000
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
VOUT-
VOUT+
0
10
20
30
50
40
60
70
0
MAX3237E
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = VCC)
MAX3237E toc10
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
500 1000 1500 2000
-SLEW, 1Mbps
+SLEW, 1Mbps
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3k + CL LOAD EACH OUTPUT
-SLEW, 2Mbps
+SLEW, 2Mbps
-6
-2
-4
2
0
4
6
-3
-5
1
-1
3
5
2.0 3.0 3.52.5 4.0 4.5 5.0
MAX3237E toc13
SUPPLY VOLTAGE (V)
TRANSMITTER OUTPUT VOLTAGE (V)
VOUT-
VOUT+
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3k + 1000pF
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE (MBAUD = GND)
4
6
8
10
12
14
16
0
MAX3246E
SLEW RATE vs. LOAD CAPACITANCE
MAX3237E toc16
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
2000 30001000 4000 5000
SR+
SR-
Maxim Integrated
6
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MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Typical Operating Characteristics (continued)
*These pins have an active positive feedback resistor internal to the MAX3237E, allowing unused inputs to be left unconnected.
PIN
NAME FUNCTION
MAX3222E MAX3232E
MAX3237E
MAX3241E
MAX3246E
TQFN SO/
DIP
TSSOP/
SSOP TQFN
SO/DIP/
SSOP/
16-PIN
TSSOP
20-PIN
TSSOP
SSOP/
SO/
TSSOP
TQFN
19 1 1 13* 23 22 B3 EN Receiver Enable. Active
low.
1 2 2 16 1 2 28 28 28 F3 C1+
Positive Terminal
of Voltage-Doubler
Charge-Pump Capacitor
20 3 3 15 2 3 27 27 27 F1 V+ +5.5V Generated by the
Charge Pump
2 4 4 1 3 4 25 24 23 F4 C1-
Negative Terminal
of Voltage-Doubler
Charge-Pump Capacitor
3 5 5 2 4 5 1 1 29 E1 C2+
Positive Terminal of
Inverting Charge-Pump
Capacitor
4 6 6 3 5 6 3 2 30 D1 C2-
Negative Terminal of
Inverting Charge-Pump
Capacitor
5 7 7 4 6 7 4 3 31 C1 V- -5.5V Generated by the
Charge Pump
6, 15 8,
15 8, 17 5,
12 7, 14 8, 17 5, 6, 7, 10,
12
9, 10,
11
6, 7,
8F6, E6, D6 T_OUT RS-232 Transmitter
Outputs
7, 14 9,
14 9, 16 6, 11 8, 13 9, 16 8, 9, 11 4–8 1–5 A4, A5, A6,
B6, C6 R_IN RS-232 Receiver Inputs
8, 13 10,
13 10, 15 7, 10 9, 12 12, 15 18, 20, 21 15–19
13,
14,
15,
17,
18
C2, B1, A1,
A2, A3 R_OUT TTL/CMOS Receiver
Outputs
10, 11 11,
12 12, 13 8, 9 10, 11 13, 14
17*, 19*,
22*, 23*,
24*
12, 13,
14
10,
11, 12 E3, E2, D2 T_IN TTL/CMOS Transmitter
Inputs
www.maximintegrated.com Maxim Integrated
7
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Pin Description
PIN
NAME FUNCTION
MAX3222E MAX3232E
MAX3237E
MAX3241E
MAX3246E
TQFN SO/
DIP
TSSOP/
SSOP TQFN
SO/DIP/
SSOP/
16-PIN
TSSOP
20-PIN
TSSOP
SSOP/
SO/
TSSOP
TQFN
16 16 18 13 15 18 2 25 24 F5 GND Ground
17 17 19 14 16 19 26 26 26 F2 VCC +3.0V to +5.5V Supply
Voltage
18 18 20 14* 22 21 B2 SHDN Shutdown Control.
Active low.
9, 12 11, 14 1, 10,
11, 20
9, 16,
25,
32
C3, D3, B4,
C4, D4, E4,
B5, C5, D5,
E5
N.C.
No Connection. For
MAX3246E, these
locations are not
populated with solder
bumps.
15* MBAUD
MegaBaud Control
Input. Connect to GND
for normal operation;
connect to VCC for
1Mbps transmission
rates.
16 20,
21
19,
20 R_
OUTB
Noninverting
Complementary
Receiver Outputs.
Always active.
EP
Exposed Pad. Solder
the exposed pad to the
ground plane or leave
unconnected (for TQFN
only).
www.maximintegrated.com Maxim Integrated
8
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Pin Description (continued)
Detailed Description
Dual Charge-Pump Voltage Converter
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E’s internal power supply consists of a regu-
lated dual charge pump that provides output voltages
of +5.5V (doubling charge pump) and -5.5V (inverting
charge pump) over the +3.0V to +5.5V VCC range. The
charge pump operates in discontinuous mode; if the
output voltages are less than 5.5V, the charge pump
is enabled, and if the output voltages exceed 5.5V, the
charge pump is disabled. Each charge pump requires a
flying capacitor (C1, C2) and a reservoir capacitor (C3,
C4) to generate the V+ and V- supplies (Figure 1).
RS-232 Transmitters
The transmitters are inverting level translators that convert
TTL/CMOS-logic levels to ±5V EIA/TIA-232-compliant
levels.
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E transmitters guarantee a 250kbps data rate
with worst-case loads of 3kΩ in parallel with 1000pF,
providing compatibility with PC-to-PC communication
software (such as LapLink™). Transmitters can be paral-
leled to drive multiple receivers or mice.
The MAX3222E/MAX3237E/MAX3241E/MAX3246E
transmitters are disabled and the outputs are forced into
a high-impedance state when the device is in shutdown
mode (SHDN = GND). The MAX3222E/MAX3232E/
MAX3237E/MAX3241E/MAX3246E permit the outputs to
be driven up to ±12V in shutdown.
The MAX3222E/MAX3232E/MAX3241E/MAX3246E
transmitter inputs do not have pullup resistors. Connect
unused inputs to GND or VCC. The MAX3237E’s transmit-
ter inputs have a 400kΩ active positive-feedback resistor,
allowing unused inputs to be left unconnected.
MAX3237E MegaBaud Operation
For higher-speed serial communications, the MAX3237E
features MegaBaud operation. In MegaBaud operating
mode (MBAUD = VCC), the MAX3237E transmitters guar-
antee a 1Mbps data rate with worst-case loads of 3kΩ in
parallel with 250pF for +3.0V < VCC < +4.5V. For +5V
±10% operation, the MAX3237E transmitters guarantee a
1Mbps data rate into worst-case loads of 3kΩ in parallel
with 1000pF.
RS-232 Receivers
The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3222E/MAX3237E/MAX3241E/
MAX3246E receivers have inverting three-state outputs.
Drive EN high to place the receiver(s) into a high-imped-
ance state. Receivers can be either active or inactive in
shutdown (Table 1).
Figure 1. Slew-Rate Test Circuits
LapLink is a trademark of Traveling Software.
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5k
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3
C1
C2
0.1µF
VCC
T_ OUT
T_ IN
GND 7k150pF
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5k
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3
C1
C2
0.1µF
VCC
T_ OUT
T_ IN
GND 3k1000pF
(2500pF, MAX3237E only)
MINIMUM SLEW-RATE TEST CIRCUIT MAXIMUM SLEW-RATE TEST CIRCUIT
www.maximintegrated.com Maxim Integrated
9
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
The complementary outputs on the MAX3237E/
MAX3241E (R_OUTB) are always active, regardless of
the state of EN or SHDN. This allows the device to be
used for ring indicator applications without forward biasing
other devices connected to the receiver outputs. This is
ideal for systems where VCC drops to zero in shutdown
to accommodate peripherals such as UARTs (Figure 2).
MAX3222E/MAX3237E/MAX3241E/
MAX3246E Shutdown Mode
Supply current falls to less than 1μA in shutdown mode
(SHDN = low). The MAX3237E’s supply current falls
to10nA (typ) when all receiver inputs are in the invalid
range (-0.3V < R_IN < +0.3V). When shut down, the
device’s charge pumps are shut off, V+ is pulled down
to VCC, V- is pulled to ground, and the transmitter out-
puts are disabled (high impedance). The time required
to recover from shutdown is typically 100μs, as shown
in Figure 3. Connect SHDN to VCC if shutdown mode is
not used. SHDN has no effect on R_OUT or R_OUTB
(MAX3237E/MAX3241E).
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated to protect against electrostatic dis-
charges encountered during handling and assembly. The
driver outputs and receiver inputs of the MAX3222E/
MAX3232E/MAX3237E/MAX3241E/MAX3246E have
extra protection against static electricity. Maxim’s engi-
neers have developed state-of-the-art structures to pro-
tect these pins against ESD of ±15kV without damage.
The ESD structures withstand high ESD in all states:
normal operation, shutdown, and powered down. After
an ESD event, Maxim’s E versions keep working without
latchup, whereas competing RS-232 products can latch
and must be powered down to remove latchup.
Furthermore, the MAX3237E logic I/O pins also have
±15kV ESD protection. Protecting the logic I/O pins
to ±15kV makes the MAX3237E ideal for data cable
applications.
Figure 2. Detection of RS-232 Activity when the UART
and Interface are Shut Down; Comparison of MAX3237E/
MAX3241E (b) with Previous Transceivers (a)
Figure 3. Transmitter Outputs Recovering from Shutdown or
Powering Up
T1OUT
R1OUTB
Tx
5k
UART
V
CC
T1IN
LOGIC
TRANSITION
DETECTOR
R1IN
R1OUT
THREE-STATED
EN = V
CC
SHDN = GND
V
CC
TO
µP
Rx
PREVIOUS
RS-232
Tx
UART
PROTECTION
DIODE
PROTECTION
DIODE
SHDN = GND
V
CC
V
CC
GND
Rx
5k
a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM
A ACTIVE RECEIVER OUTPUT IN SHUTDOWN.
b) NEW MAX3237E/MAX3241E: EN SHUTS DOWN RECEIVER OUTPUTS
B (EXCEPT FOR B OUTPUTS), SO NO CURRENT FLOWS TO UART IN SHUTDOWN.
B B OUTPUTS INDICATE RECEIVER ACTIVITY DURING SHUTDOWN WITH EN HIGH.
GND
MAX3237E/
MAX3241E
40µs/div
SHDN
T2OUT
T1OUT
5V/div
0
2V/div
0
V
CC
= 3.3V
C1–C4 = 0.1µF
www.maximintegrated.com Maxim Integrated
10
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
ESD protection can be tested in various ways; the trans-
mitter outputs and receiver inputs for the MAX3222E/
MAX3232E/MAX3241E/MAX3246E are characterized for
protection to the following limits:
±15kV using the Human Body Model
±8kV using the Contact Discharge method specified
in IEC 1000-4-2
±9kV (MAX3246E only) using the Contact Discharge
method specified in IEC 1000-4-2
±15kV using the Air-Gap Discharge method specified
in IEC 1000-4-2
Figure 4a. Human Body ESD Test Model Figure 4b. Human Body Model Current Waveform
Figure 5a. IEC 1000-4-2 ESD Test Model Figure 5b. IEC 1000-4-2 ESD Generator Current Waveform
Table 1. MAX3222E/MAX3237E/MAX3241E/
MAX3246E Shutdown and Enable Control
Truth Table
SHDN EN T_OUT R_OUT
R_OUTB
(MAX3237E/
MAX3241E)
0 0 High
impedance Active Active
0 1 High
impedance
High
impedance Active
1 0 Active Active Active
1 1 Active High
impedance Active
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
R
C
1M
R
D
1500
HIGH-
VOLTAGE
DC
SOURCE
DEVICE-
UNDER-
TEST
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC
50M to 100M
RD
330
HIGH-
VOLTAGE
DC
SOURCE
DEVICE-
UNDER-
TEST
tr = 0.7ns to 1ns
30ns
60ns
t
100%
90%
10%
I
PEAK
I
www.maximintegrated.com Maxim Integrated
11
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
For the MAX3237E, all logic and RS-232 I/O pins are
characterized for protection to ±15kV per the Human
Body Model.
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents test
setup, test methodology, and test results.
Human Body Model
Figure 4a shows the Human Body Model, and Figure
4b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the test device through a
1.5kΩ resistor.
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and per-
formance of finished equipment; it does not specifically
refer to integrated circuits. The MAX3222E/MAX3232E/
MAX3237E/MAX3241E/MAX3246E help you design
equipment that meets level 4 (the highest level) of IEC
1000-4-2, without the need for additional ESDprotection
components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak cur-
rent in IEC 1000-4-2, because series resistance is lower
in the IEC 1000-4-2 model. Hence, the ESD withstand
voltage measured to IEC 1000-4-2 is generally lower
than that measured using the Human Body Model. Figure
5a shows the IEC 1000-4-2 model, and Figure 5b shows
the current waveform for the ±8kV IEC 1000-4-2 level 4
ESD Contact Discharge test. The Air-Gap Discharge test
involves approaching the device with a charged probe.
The Contact Discharge method connects the probe to the
device before the probe is energized.
Machine Model
The Machine Model for ESD tests all pins using a 200pF
storage capacitor and zero discharge resistance. Its
objective is to emulate the stress caused by contact that
occurs with handling and assembly during manufacturing.
All pins require this protection during manufacturing, not
just RS-232 inputs and outputs. Therefore, after PC board
assembly, the Machine Model is less relevant to I/O ports.
Table 2. Required Minimum Capacitor
Values
Table 3. Logic-Family Compatibility with
Various Supply Voltages
Figure 6a. MAX3241E Transmitter Output Voltage vs. Load
Current Per Transmitter
VCC
(V)
C1
(ΜF)
C2, C3, C4
(ΜF)
MAX3222E/MAX3232E/MAX3241E
3.0 to 3.6 0.1 0.1
4.5 to 5.5 0.047 0.33
3.0 to 5.5 0.1 0.47
MAX3237E/MAX3246E
3.0 to 3.6 0.22 0.22
3.15 to 3.6 0.1 0.1
4.5 to 5.5 0.047 0.33
3.0 to 5.5 0.22 1.0
SYSTEM
POWER-SUPPLY
VOLTAGE
(V)
VCC SUPPLY
VOLTAGE
(V)
COMPATIBILITY
3.3 3.3 Compatible with all
CMOS families
5 5
Compatible with
all TTL and CMOS
families
5 3.3
Compatible with ACT
and HCT CMOS,
and with AC, HC, or
CD4000 CMOS
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
012345678910
MAX3222E-fig06a
LOAD CURRENT PER TRANSMITTER (mA)
TRANSMITTER OUTPUT VOLTAGE (V)
V
OUT+
V
OUT-
V
OUT+
V
OUT-
V
CC
V
CC
= 3.0V
www.maximintegrated.com Maxim Integrated
12
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Applications Information
Capacitor Selection
The capacitor type used for C1–C4 is not critical for prop-
er operation; polarized or nonpolarized capacitors can
be used. The charge pump requires 0.1μF capacitors for
3.3V operation. For other supply voltages, see Table 2 for
required capacitor values. Do not use values smaller than
those listed in Table 2. Increasing the capacitor values
(e.g., by a factor of 2) reduces ripple on the transmitter
outputs and slightly reduces power consumption. C2, C3,
and C4 can be increased without changing C1’s value.
However, do not increase C1 without also increasing
the values of C2, C3, C4, and CBYPASS to maintain
the proper ratios (C1 to the other capacitors).
When using the minimum required capacitor values,
make sure the capacitor value does not degrade
excessively with temperature. If in doubt, use capacitors
with a larger nominal value. The capacitor’s equivalent
series resistance (ESR), which usually rises at low tem-
peratures, influences the amount of ripple on V+ and V-.
Power-Supply Decoupling
In most circumstances, a 0.1μF VCC bypass capacitor
is adequate. In applications sensitive to power-supply
noise, use a capacitor of the same value as charge-pump
capacitor C1. Connect bypass capacitors as close to the
IC as possible.
Operation Down to 2.7V
Transmitter outputs meet EIA/TIA-562 levels of ±3.7V
with supply voltages as low as 2.7V.
Figure 6b. Mouse Driver Test Circuit
MAX3241E
EN
23
R5OUT
15
R4OUT
16
R3OUT
17
R2OUT
18
R1OUT
19
R2OUTB
20
R1OUTB
21
5k
5k
5k
5k
5k
R5IN 8
V
CC
R4IN 7
6
R2IN 5
R1IN 4
SHDN 22
GND
25
T3IN
12
T2IN
13
T1IN
14
C2-
2
C2+
1
C1-
24
C1+
28
T3OUT 11
+V
COMPUTER SERIAL PORT
+V
-V
GND
Tx
T2OUT 10
T1OUT 9
V- 3
V+ 27
V
CC
V
CC
C4
C3 C1
C2
C
BYPASS
V
CC
= +3.0V TO +5.5V
26
R3IN
MOUSE
www.maximintegrated.com Maxim Integrated
13
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Transmitter Outputs Recovering
from Shutdown
Figure 3 shows two transmitter outputs recovering from
shutdown mode. As they become active, the two trans-
mitter outputs are shown going to opposite RS-232 levels
(one transmitter input is high; the other is low). Each
transmitter is loaded with 3kΩ in parallel with 2500pF.
The transmitter outputs display no ringing or undesirable
transients as they come out of shutdown. Note that the
transmitters are enabled only when the magnitude of V-
exceeds approximately -3.0V.
Mouse Drivability
The MAX3241E is designed to power serial mice while
operating from low-voltage power supplies. It has been
tested with leading mouse brands from manufacturers
such as Microsoft and Logitech. The MAX3241E success-
fully drove all serial mice tested and met their current and
voltage requirements.
Figure 7. Loopback Test Circuit
Figure 8. MAX3241E Loopback Test Result at 120kbps
Figure 9. MAX3241E Loopback Test Result at 250kbps
Figure 10. MAX3237E Loopback Test Result at 1000kbps
(MBAUD = VCC)
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5k
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
V
CC
C4
C3
C1
C2
0.1µF
V
CC
T_ OUT
T_ IN
GND
1000pF
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
V
CC
= 3.3V
C1–C4 = 0.1µF
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
V
CC
= 3.3V, C1–C4 = 0.1µF
+5V
0
+5V
0
-5V
+5V
0
T_IN
T_OUT
5k + 250pF
R_OUT
400ns/div
VCC = 3.3V
C1–C4 = 0.1µF
www.maximintegrated.com Maxim Integrated
14
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Figure 6a shows the transmitter output voltages under
increasing load current at +3.0V. Figure 6b shows a typi-
cal mouse connection using the MAX3241E.
High Data Rates
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E maintain the RS-232 ±5V minimum trans-
mitter output voltage even at high data rates. Figure 7
shows a transmitter loopback test circuit. Figure 8 shows
a loopback test result at 120kbps, and Figure 9 shows
the same test at 250kbps. For Figure 8, all transmitters
were driven simultaneously at 120kbps into RS-232 loads
in parallel with 1000pF. For Figure 9, a single transmitter
was driven at 250kbps, and all transmitters were loaded
with an RS-232 receiver in parallel with 1000pF.
The MAX3237E maintains the RS-232 ±5.0V minimum
transmitter output voltage at data rates up to 1Mbps.
Figure 10 shows a loopback test result at 1Mbps with
MBAUD = VCC. For Figure 10, all transmitters were
loaded with an RS-232 receiver in parallel with 250pF.
Interconnection with 3V and 5V Logic
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E can directly interface with various 5V logic
families, including ACT and HCT CMOS. See Table 3
for more information on possible combinations of inter-
connections.
UCSP Reliability
The UCSP represents a unique packaging form factor that
may not perform equally to a packaged product through
traditional mechanical reliability tests. UCSP reliability is
integrally linked to the user’s assembly methods, circuit
board material, and usage environment. The user should
closely review these areas when considering use of a
UCSP package. Performance through Operating Life Test
and Moisture Resistance remains uncompromised as the
wafer-fabrication process primarily determines it.
Mechanical stress performance is a greater consideration
for a UCSP package. UCSPs are attached through direct
solder contact to the user’s PC board, foregoing the
inherent stress relief of a packaged product lead frame.
Solder joint contact integrity must be considered. Table
4 shows the testing done to characterize the UCSP reli-
ability performance. In conclusion, the UCSP is capable
of performing reliably through environmental stresses as
indicated by the results in the table. Additional usage data
and recommendations are detailed in Application Note
1891: Wafer-Level Packaging (WLP) and Its Applications.
Table 4. Reliability Test Data
TEST CONDITIONS DURATION FAILURES PER
SAMPLE SIZE
Temperature Cycle TA = -35°C to +85°C,
TA = -40°C to +100°C
150 cycles,
900 cycles
0/10,
0/200
Operating Life TA = +70°C 240 hours 0/10
Moisture Resistance TA = +20°C to +60°C, 90% RH 240 hours 0/10
Low-Temperature Storage TA = -20°C 240 hours 0/10
Low-Temperature Operational TA = -10°C 24 hours 0/10
Solderability 8-hour steam age 0/15
ESD ±15kV, Human Body Model 0/5
High-Temperature Operating Life TJ = +150°C 168 hours 0/45
www.maximintegrated.com Maxim Integrated
15
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
20
19
18
17
16
15
14
13
1
2
3
8
12
11
10
4
5
6
7
SHDN
V
CC
GND
T1OUT
C1-
V+
C1+
EN
R1IN
R1OUT
T1IN
T2IN
T2OUT
V-
C2-
C2+
9
R2IN
R2OUT
TSSOP/SSOP
N.C.
N.C.
MAX3222E
20
19
18
17
16
15
14
13
1
2
3
8
12
11
10
4
5
6
7
N.C.
V
CC
GND
T1OUT
C1-
V+
C1+
N.C.
R1IN
R1OUT
T2IN
R2OUT
T2OUT
V-
C2-
C2+
9
R2IN
N.C.
TSSOP
T1IN
N.C.
MAX3232E
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
V
CC
GND
T1OUT
R1INC2+
C1-
V+
C1+
MAX3232E
R1OUT
T1IN
T2IN
R2OUTR2IN
T2OUT
V-
C2-
SO/DIP/SSOP/TSSOP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
C1+
V+
V
CC
GND
C1-
EN
R5OUT
SHDN
R1OUTB
R2OUTB
R1OUT
R2OUT
R3OUT
R4OUT
T1IN
T2IN
T3IN
T3OUT
T2OUT
T1OUT
R5IN
R4IN
R3IN
R2IN
R1IN
V-
C2-
C2+
SSOP/SO/TSSOP TQFN
MAX3241E
TOP VIEW
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
C1+
V+
V
CC
C1-
T1IN
T2IN
MBAUD
T3IN
R1OUT
R2OUT
T4IN
R3OUT
T5IN
R1OUTB
SHDN
EN
T5OUT
R3IN
T4OUT
R2IN
R1IN
T3OUT
T2OUT
T1OUT
V-
C2-
GND
C2+
SSOP
MAX3237E
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
SHDN
V
CC
GND
T1OUT
C1-
V+
C1+
EN
R1IN
R1OUT
T1IN
T2IN
T2OUT
V-
C2-
C2+
10
9R2OUTR2IN
SO/DIP
MAX3222E
32
31
30
29
28
27
26
N.C.
V-
C2-
C2+
C1+
V+
V
CC
25 N.C.
9
10
11
12
13
14
15
N.C.
T3IN
T2IN
T1IN
R5OUT
R4OUT
R3OUT
16N.C.
17
18
19
20
21
22
23
R2OUT
R1OUT
R2OUTB
R1OUTB
SHDN
EN
C1-
8
7
6
5
4
3
2
T3OUT *EP
*CONNECT EP TO GND.
T2OUT
T1OUT
R5IN
R4IN
R3IN
R2IN
MAX3241E
1R1IN 24 GND
TOP VIEW
++++
+ +
+
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16
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Pin Congurations
UCSP
F6F5F4F3F2
E6E3
D6
C6
B6B3
A2 A3 A4 A5 A6
TOP VIEW
(BUMPS ON BOTTOM)
T1OUT
GNDC1-C1+V
CC
R3IN
R2INR1INR5OUTR4OUT
R4IN
R5IN
T3OUT
T2OUT
B2: SHDN
C2: R1OUT
D2: T3IN
E2: T2IN
B3: EN
E3: T1IN
BUMPS B4, B5, C3, C4,
C5, D3, D4, D5, E4, AND
E5 NOT POPULATED
*CONNECT EP TO GND.
E2
D2
C2
B2
F1
E1
D1
C1
B1
A1
V+
R3OUT
R2OUT
V-
C2-
C2+
MAX3246E
+
19
20
18
17
7
6
8
C1-
C2-
V-
9
C1+
R1IN
N.C.
T1IN
T1OUT
1 2
SHDN
4 5
15 14 12 11
EN
V+
*EP
N.C.
R2OUT
R2IN
T2OUT
MAX3222E
C2+ R1OUT
3
13
V
CC
16 10 T2IN
GND
TQFN
*EP
TOP VIEW
15
16
14
13
6
5
7
C2+
V-
8
C1-
R1IN
T1IN
T1OUT
1 2
V
CC
4
12 11 9
V+
C1+
T2IN
R2OUT
R2IN
T2OUT
MAX3232E
C2- R1OUT
3
10
GND
TQFN
TOP VIEW
+ +
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17
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Pin Congurations (continued)
R2OUT10
1
R1OUT13
R2IN 9
18
GND
16
RS-232
OUTPUTS
TTL/CMOS
INPUTS
T2IN
11
T1IN
12
C2-
6
C2+
5
C1-
4
C1+
2
R1IN 14
T2OUT 8
T1OUT 15
V- 7
V+ 3
V
CC
17
C1
0.1µF
C2
0.1µF
C
BYPASS
+3.3V
RS-232
INPUTS
TTL/CMOS
OUTPUTS 5k
5k
EN
SHDN
C3
*
0.1µF
C4
0.1µF
NOTE: PIN NUMBERS REFER TO SO/DIP PACKAGES.
MAX3222E PINOUT REFERS TO SO/DIP PACKAGES.
MAX3232E PINOUT REFERS TO TSSOP/SSOP/SO/DIP PACKAGES
*
C3 CAN BE RETURNED TO EITHER V
CC
OR GROUND.
R2OUT9
R1OUT12
R2IN 8
GND
15
RS-232
OUTPUTS
TTL/CMOS
INPUTS
T2IN
10
T1IN
11
C2-
5
C2+
4
C1-
3
C1+
1
R1IN 13
T2OUT 7
T1OUT 14
V- 6
V+ 2
V
CC
C4
0.1µF
16
C1
0.1µF
C2
0.1µF
C
BYPASS
+3.3V
RS-232
INPUTS
TTL/CMOS
OUTPUTS
C3
*
0.1µF
5k
5k
SEE TABLE 2 FOR CAPACITOR SELECTION.
MAX3222E MAX3232E
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18
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Typical Operating Circuits
EN
23
R5OUT
15
R4OUT
16
R3OUT
17
R2OUT
18
R1OUT
19
R2OUTB
20
R1OUTB
21
TTL/CMOS
OUTPUTS
5k
5k
5k
5k
5k
R5IN 8
*
C3 CAN BE RETURNED TO EITHER V
CC
OR GROUND.
R4IN 7
R3IN 6
R2IN 5
R1IN 4
RS-232
INPUTS
SHDN 22
GND
25
RS-232
OUTPUTS
TTL/CMOS
INPUTS
T3IN
12
T2IN
13
T1IN
14
C2-
2
C2+
1
C1-
24
C1+
28
T3OUT 11
T2OUT 10
T1OUT 9
V- 3
V+
27
V
CC
C4
0.1µF
C3
*
0.1µF
C1
0.1µF
C2
0.1µF
26
+3.3V
C
BYPASS
MAX3241E
EN
13
R3OUT
18
R2OUT
20
R1OUT
21
R1OUTB
16
LOGIC
OUTPUTS
5k
5k
5k
R3IN 11
R2IN 9
R1IN 8
RS-232
INPUTS
GND
2
RS-232
OUTPUTS
LOGIC
INPUTS
T3IN
22
T2IN
23
T1IN
24
C2-
3
C2+
1
C1-
25
C1+
28
T3OUT 7
T2OUT 6
T1OUT 5
T1
T2
T3
R1
R2
R3
V- 4
V+
27
V
CC
0.1µF
C3*
0.1µF
0.1µF
0.1µF
26
MBAUD 15
T5IN
17
T4IN
19
T5OUT 12
T4OUT 10
SHDN 14
T4
T5
C
BYPASS
+3.3V
MAX3237E
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19
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Typical Operating Circuits (continued)
EN
B3
R5OUT
A3
R4OUT
A2
R3OUT
A1
R2OUT
B1
R1OUT
C2
TTL/CMOS
OUTPUTS
5k
5k
5k
5k
5k
R5IN C6
*C3 CAN BE RETURNED TO EITHER VCC OR GROUND.
R4IN B6
R3IN A6
R2IN A5
R1IN A4
RS-232
INPUTS
SHDN B2
GND
F5
RS-232
OUTPUTS
TTL/CMOS
INPUTS
T3IN
D2
T2INE2
T1IN
E3
C2-
D1
C2+
E1
C1-
F4
C1+
F3
T3OUT D6
T2OUT E6
T1OUT F6
V- C1
V+
F1
VCC
C4
0.1µF
C3*
0.1µF
C1
0.1µF
C2
0.1µF
F2
+3.3V
CBYPASS
MAX3246E
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20
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Typical Operating Circuits (continued)
+Denotes a lead(Pb)-free/RoHS-compliant package.
†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 Reliability Notice in the UCSP
Reliability section of this datasheet for more information.
**EP = Exposed pad.
PART TEMP RANGE PIN-PACKAGE
MAX3232ECTE+ 0°C to +70°C 16 TQFN-EP**
(5mm x 5mm)
MAX3232ECUE+ 0°C to +70°C 16 TSSOP
MAX3232ECUP+ 0°C to +70°C 20 TSSOP
MAX3232ECSE+ 0°C to +70°C 16 SOIC
MAX3232EESE+ -40°C to +85°C 16 SOIC
MAX3232EEAE+ -40°C to +85°C 16 SSOP
MAX3232EEWE+ -40°C to +85°C 16 Wide SO
MAX3232EEPE+ -40°C to +85°C 16 Plastic DIP
MAX3232EETE+ -40°C to +85°C 16 TQFN-EP**
(5mm x 5mm)
MAX3232EEUE+ -40°C to +85°C 16 TSSOP
MAX3232EEUP+ -40°C to +85°C 20 TSSOP
MAX3237ECAI+ 0°C to +70°C 28 SSOP
MAX3237EEAI+ -40°C to +85°C 28 SSOP
MAX3241ECAI+ 0°C to +70°C 28 SSOP
MAX3241ECWI+ 0°C to +70°C 28 Wide SO
MAX3241ECUI+ 0°C to +70°C 28 TSSOP
MAX3241ECTJ+ 0°C to +70°C 32 TQFN-EP**
(7mm x 7mm)
MAX3241EEAI+ -40°C to +85°C 28 SSOP
MAX3241EEWI+ -40°C to +85°C 28 Wide SO
MAX3241EEUI+ -40°C to +85°C 28 TSSOP
MAX3246ECBX-T+ 0°C to +70°C 6 x 6 UCSP
MAX3246EEBX-T+ -40°C to +85°C 6 x 6 UCSP
PART
NO. OF
DRIVERS/
RECEIVERS
LOW-
POWER
SHUTDOWN
GUARANTEED
DATA RATE
(bps)
MAX3222E 2/2 P250k
MAX3232E 2/2 250k
MAX3237E
(Normal)5/3 P250k
MAX3237E
(MegaBaud) 5/3 P1M
MAX3241E 3/5 P250k
MAX3246E 3/5 P250k
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
20 TQFN T2055+5 21-0140 90-0010
20 TSSOP H20+2 21-0066 90-0116
20 SSOP A20+1 21-0056 90-0094
18 Wide SO W18+1 21-0042 90-0181
18 PDIP P18+5 21-0043
16 SOIC S16 +1 21-0041 90-0097
16 SSOP A16+2 21-0056 90-0106
16 Wide SO W16+3 21-0042 90-0107
16 PDIP P16+1 21-0043
16 TQFN T1655+2 21-0140 90-0072
16 TSSOP U16+1 21-0066 90-0117
28 SSOP A28+1 21-0056 90-0095
28 Wide SO W28+6 21-0042 90-0109
28 TSSOP U28+2 21-0066 90-0171
32 TQFN T3277+2 21-0144 90-0125
6x6 HCSP B36+3 21-0082
Refer to
Application
Note 1891
www.maximintegrated.com Maxim Integrated
21
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
Ordering Information (continued) Selector Guide
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
11 10/07 Corrected Package Information 22–28
12 12/10 Changed all parts to lead free in the Ordering Information, added automotive qualied
part to Ordering Information, corrected capacitor in Typical Operating Circuits 1, 19
13 12/18 Updated Ordering Information and Package Information tables 21
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2018 Maxim Integrated Products, Inc.
22
MAX3222E/MAX3232E/
MAX3237E/MAX3241E/
MAX3246E
±15kV ESD-Protected, Down to 10nA,
3.0V to 5.5V, Up to 1Mbps,
True RS-232 Transceivers
Revision History
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.