AVAILABLE
EVALUATION KIT AVAILABLE
Functional Diagrams
Pin Configurations appear at end of data sheet.
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
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 con-
sumption, 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 protected to the above standards, while the transmit-
ter output pins are protected to ±15kV using the Human
Body Model.
A proprietary low-dropout transmitter output stage delivers
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 opera-
tion from a +3.3V supply. Each device guarantees opera-
tion at data rates of 250kbps while maintaining RS-232
output levels. The MAX3237E guarantees operation 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
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
19-1298; Rev 12; 12/10
Ordering Information
Ordering Information continued at end of data sheet.
+
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.
Pin Configurations, Selector Guide, and Typical Operating
Circuits appear at end of data sheet.
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
MegaBaud and UCSP are trademarks of Maxim Integrated
Products, Inc.
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
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)
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.
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
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)
MAX3222E, MAX3232E,
MAX3241E, MAX3246E 0.3 1
Supply Current SHDN = VCC, no load
MAX3237E 0.5 2.0
mA
SHDN = GND 1 10 μA
Shutdown Supply Current 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
VCC = +3.3V 2.0
Input Logic High T_IN, EN,SHDN, MBAUD VCC = +5.0V 2.4 V
Transmitter Input Hysteresis 0.5 V
T_IN, EN,SHDN MAX3222E, MAX3232E,
MAX3241E, MAX3246E ±0.01 ±1
Input Leakage Current
T_IN, SHDN, MBAUD MAX3237E (Note 5) 9 18
μA
2
Maxim Integrated
±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)
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
VCC = +3.3V 0.6 1.1
Input Threshold Low TA = +25°C VCC = +5.0V 0.8 1.5 V
VCC = +3.3V 1.5 2.4
Input Threshold High TA = +25°C VCC = +5.0V 2.0 2.4 V
Input Hysteresis 0.5 V
Input Resistance TA = +25°C 3 5 7 k
TRANSMITTER OUTPUTS
Output Voltage Swing All transmitter outputs loaded with 3k! to ground
(Note 6) ±5 ±5.4 V
Output Resistance VCC = 0V, transmitter output = ±2V 300 50k
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
3k to GND, T1OUT and T2OUT loaded with 2.5mA
each
±5 V
ESD PROTECTION
Human Body Model ±15
IEC 1000-4-2 Air-Gap Discharge (except MAX3237E) ±15
IEC 1000-4-2 Contact Discharge (except MAX3237E) ±8
R_IN, T_OUT
IEC 1000-4-2 Contact Discharge (MAX3246E only) ±9
kV
Human Body Model ±15
IEC 1000-4-2 Air-Gap Discharge ±15
T_IN, R_IN, R_OUT, EN,SHDN,
MBAUD MAX3237E
IEC 1000-4-2 Contact Discharge ±8
kV
Maxim Integrated
3
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—MAX3237E
(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 testedat +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 CONDITIONS MIN TYP MAX UNITS
RL = 3kΩ, CL = 1000pF, one transmitter switching,
MBAUD = GND 250
VCC = +3.0V to +4.5V, RL = 3kΩ, CL = 250pF,
one transmitter switching, MBAUD = VCC 1000Maximum Data Rate
VCC = +4.5V to +5.5V, RL = 3kΩ, CL = 1000pF,
one transmitter switching, MBAUD = VCC 1000
kbps
tPHL 0.15
Receiver Propagation Delay R_IN to R_OUT, CL = 150pF tPLH 0.15 µs
Receiver Output Enable Time Normal operation 2.6 µs
Receiver Output Disable Time Normal operation 2.4 µs
|tPHL - tPLH|, MBAUD = GND
Transmitter Skew (Note 7) |tPHL - tPLH|, MBAUD = VCC
100 ns
Receiver Skew |tPHL - tPLH|50ns
MBAUD = GND 6 30
CL = 150pF
to 1000pF MBAUD = VCC 24 150
VCC = +3.3V,
RL = 3kΩ to 7kΩ,
+3.0V to -3.0V or
-3.0V to +3.0V,
TA = +25°C CL = 150pF to 2500pF,
MBAUD = GND 430
V/µs
Transition-Region Slew Rate
TIMING CHARACTERISTICS—MAX3222E/MAX3232E/MAX3241E/MAX3246E
(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 SYMBOL CONDITIONS MIN TYP MAX UNITS
TA = TMIN to TMAX
(MAX3222E/MAX3232E/
MAX3241E) (Note 6)
250
Maximum Data Rate
RL = 3kΩ,
CL = 1000pF,
one transmitter
switching TA = + 25°C ( M AX 3246E ) 250
kbps
tPHL 0.15
Receiver Propagation Delay tPLH
Receiver input to receiver output,
CL = 150pF 0.15 µs
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|50ns
Transition-Region Slew Rate
V
C C
= + 3.3V , TA = + 25°C ,
RL = 3kΩ to 7kΩ , m easur ed
fr om + 3.0V to - 3.0V or - 3.0V to
+ 3.0V , one tr ansm i tter sw i tchi ng
CL = 150pF
to 1000pF 6 30 V/µs
4
Maxim Integrated
-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-
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
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
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
-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 3kΩ + CL
5
3
1
-1
-3
-5
V
OUT+
VOUT-
-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 3kΩ + CL
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE
-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
3kΩ + CL LOAD, EACH OUTPUT
2Mbps 1.5Mbps
1Mbps
2Mbps
1Mbps
1.5Mbps
__________________________________________Typical Operating Characteristics
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA = +25°C, unless otherwise noted.)
-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-
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
0
4
2
8
6
12
10
14
01000 2000 3000 4000 5000
MAX3241E
SLEW RATE vs. LOAD CAPACITANCE
MAX3237E toc05
LOAD CAPACITANCE (pF)
SLEW RATE (V/µs)
Maxim Integrated
5
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)
(VCC = +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA = +25°C, unless otherwise noted.)
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 3kΩ + CL-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 3kΩ + 1000pF
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE (MBAUD = GND)
0
10
20
30
40
50
2.0
MAX3237E SUPPLY CURRENT
vs. SUPPLY VOLTAGE (MBAUD = GND)
MAX3237E toc14
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
3.0 3.52.5 4.0 4.5 5.0
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3kΩ AND 1000pF
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+
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-
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 3kΩ + CL
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
3kΩ + CL LOAD EACH OUTPUT
-SLEW, 2Mbps
+SLEW, 2Mbps
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 3kΩ + CL
6
Maxim Integrated
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
*
These pins have an active positive feedback resistor internal to the MAX3237E, allowing unused inputs to be left unconnected.
Pin Description
PIN
MAX3222E MAX3232E MAX3241E
TQFN SO/
DIP
TSSOP/
SSOP TQFN
SO/DIP/
SSOP/
16-PIN
TSSOP
20-PIN
TSSOP
MAX3237E SSOP/
SO/
TSSOP
TQFN MAX3246E NAME FUNCTION
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,
8
F6, 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
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 (continued)
PIN
MAX3222E MAX3232E MAX3241E
TQFN SO/
DIP
TSSOP/
SSOP TQFN
SO/DIP/
SSOP/
16-PIN
TSSOP
20-PIN
TSSOP
MAX3237E SSOP/
SO/
TSSOP
TQFN MAX3246E NAME FUNCTION
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).
8
Maxim Integrated
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 con-
vert TTL/CMOS-logic levels to ±5V EIA/TIA-232-compli-
ant levels.
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E transmitters guarantee a 250kbps data rate
with worst-case loads of 3kΩin parallel with 1000pF,
providing compatibility with PC-to-PC communication
software (such as LapLink™). Transmitters can be par-
alleled 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 shut-
down 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 trans-
mitter inputs have a 400kΩactive 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 guarantee a 1Mbps data rate
with worst-case loads of 3kΩin 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 3kΩin 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-
impedance state. Receivers can be either active or
inactive in shutdown (Table 1).
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5kΩ
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3
C1
C2
0.1µF
VCC
T_ OUT
T_ IN
GND 7kΩ150pF
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5kΩ
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3
C1
C2
0.1µF
VCC
T_ OUT
T_ IN
GND 3kΩ1000pF
(2500pF, MAX3237E only)
MINIMUM SLEW-RATE TEST CIRCUIT MAXIMUM SLEW-RATE TEST CIRCUIT
Figure 1. Slew-Rate Test Circuits
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
LapLink is a trademark of Traveling Software.
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
engineers have developed state-of-the-art structures to
protect 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.
T1OUT
R1OUTB
Tx
5kΩ
UART
VCC
T1IN
LOGIC
TRANSITION
DETECTOR
R1IN
R1OUT
THREE-STATED
EN = VCC
SHDN = GND
VCC
TO
µP
Rx
PREVIOUS
RS-232
Tx
UART
PROTECTION
DIODE
PROTECTION
DIODE
SHDN = GND
VCC
VCC
GND
Rx
5kΩ
a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM
A
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
Figure 2. Detection of RS-232 Activity when the UART and
Interface are Shut Down; Comparison of MAX3237E/MAX3241E
(b) with Previous Transceivers (a)
40µs/div
SHDN
T2OUT
T1OUT
5V/div
0
2V/div
0
VCC = 3.3V
C1–C4 = 0.1µF
Figure 3. Transmitter Outputs Recovering from Shutdown or
Powering Up
10
Maxim Integrated
±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
transmitter 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 speci-
fied in IEC 1000-4-2
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
100pF
RC
1MΩ
RD
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE-
UNDER-
TEST
Figure 4a. Human Body ESD Test Model
IP 100%
90%
36.8%
tRL TIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
Ir
10%
0
0
AMPERES
Figure 4b. Human Body Model Current Waveform
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
Cs
150pF
RC
50MΩ to 100MΩ
RD
330Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE-
UNDER-
TEST
Figure 5a. IEC 1000-4-2 ESD Test Model
tr = 0.7ns to 1ns
30ns
60ns
t
100%
90%
10%
IPEAK
I
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
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
1.5kΩresistor.
IEC 1000-4-2
The IEC 1000-4-2 standard covers ESD testing and
performance of finished equipment; it does not specifi-
cally 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 ESD-
protection components.
The major difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2, because series resistance is
lower in the IEC 1000-4-2 model. Hence, the ESD with-
stand 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 resis-
tance. 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
-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)
VOUT+
VOUT-
VOUT+
VOUT-
VCC
VCC = 3.0V
Figure 6a. MAX3241E Transmitter Output Voltage vs. Load
Current Per Transmitter
Table 3. Logic-Family Compatibility with
Various Supply Voltages
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
55
Compatible with all
TTL and CMOS
families
5 3.3
C om p ati b l e w i th AC T
and H C T C M OS , and
w i th AC , H C , or
C D 4000 C M O S
12
Maxim Integrated
±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
proper operation; polarized or nonpolarized capacitors
can be used. The charge pump requires 0.1µF capaci-
tors for 3.3V operation. For other supply voltages, see
Table 2 for required capacitor values. Do not use val-
ues 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 capaci-
tors with a larger nominal value. The capacitor’s equiv-
alent series resistance (ESR), which usually rises at low
temperatures, 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.
MAX3241E
EN
23
R5OUT
15
R4OUT
16
R3OUT
17
R2OUT
18
R1OUT
19
R2OUTB
20
R1OUTB
21
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
R5IN 8
VCC
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
VCC
VCC
C4
C3 C1
C2
CBYPASS
VCC = +3.0V TO +5.5V
26
R3IN
MOUSE
Figure 6b. Mouse Driver Test Circuit
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
Figure 7. Loopback Test Circuit
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
VCC = 3.3V
C1–C4 = 0.1µF
Figure 8. MAX3241E Loopback Test Result at 120kbps
2µs/div
T1IN
T1OUT
R1OUT
5V/div
5V/div
5V/div
VCC = 3.3V, C1–C4 = 0.1µF
Figure 9. MAX3241E Loopback Test Result at 250kbps
+5V
0
+5V
0
-5V
+5V
0
T_IN
T_OUT
5kΩ + 250pF
R_OUT
400ns/div
VCC = 3.3V
C1–C4 = 0.1µF
Figure 10. MAX3237E Loopback Test Result at 1000kbps
(MBAUD = VCC)
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5kΩ
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
VCC
C4
C3
C1
C2
0.1µF
VCC
T_ OUT
T_ IN
GND
1000pF
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 3kΩin parallel with 2500pF.
The transmitter outputs display no ringing or undesir-
able 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 manu-
facturers such as Microsoft and Logitech. The
MAX3241E successfully drove all serial mice tested
and met their current and voltage requirements.
14
Maxim Integrated
±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
typical mouse connection using the MAX3241E.
High Data Rates
The MAX3222E/MAX3232E/MAX3237E/MAX3241E/
MAX3246E maintain the RS-232 ±5V minimum transmit-
ter 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 trans-
mitters 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 environ-
ment. 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 considera-
tion 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 consid-
ered. Table 4 shows the testing done to characterize
the UCSP reliability performance. In conclusion, the
UCSP is capable of performing reliably through envi-
ronmental 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
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
__________________________________________________________Pin Configurations
20
19
18
17
16
15
14
13
1
2
3
8
12
11
10
4
5
6
7
SHDN
VCC
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.
VCC
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
VCC
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+
VCC
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+
VCC
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
VCC
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+
VCC
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
++++
++
+
16
Maxim Integrated
Pin Configurations (continued)
19
20
18
17
7
6
8
C1-
C2-
V-
9
C1+
R1IN
N.C.
T1IN
T1OUT
12
SHDN
45
15 14 12 11
EN
V+
*EP
N.C.
R2OUT
R2IN
T2OUT
MAX3222E
C2+ R1OUT
3
13
VCC
16 10 T2IN
GND
TQFN
*EP
TOP VIEW
15
16
14
13
6
5
7
C2+
V-
8
C1-
R1IN
T1IN
T1OUT
12
VCC
4
12 11 9
V+
C1+
T2IN
R2OUT
R2IN
T2OUT
MAX3232E
C2- R1OUT
3
10
GND
TQFN
TOP VIEW
++
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
UCSP
F6F5F4F3F2
E6E3
D6
C6
B6B3
A2 A3 A4 A5 A6
TOP VIEW
(BUMPS ON BOTTOM)
T1OUT
GNDC1-C1+VCC
R3IN
R2INR1INR5OUTR4OUT
R4IN
R5IN
T3OUT
T2OUT
B2: SHDN
C2: R1OUT
D2: T3IN
E2: T2IN
B3: EN
E3: T1IN
*CONNECT EP TO GND.
BUMPS B4, B5, C3, C4,
C5, D3, D4, D5, E4, AND
E5 NOT POPULATED
E2
D2
C2
B2
F1
E1
D1
C1
B1
A1
V+
R3OUT
R2OUT
V-
C2-
C2+
MAX3246E
+
Maxim Integrated
17
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
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
VCC
17
C1
0.1µF
C2
0.1µF
CBYPASS
+3.3V
RS-232
INPUTS
TTL/CMOS
OUTPUTS 5kΩ
5kΩ
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 VCC 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
VCC
C4
0.1µF
16
C1
0.1µF
C2
0.1µF
CBYPASS
+3.3V
RS-232
INPUTS
TTL/CMOS
OUTPUTS
C3*
0.1µF
5kΩ
5kΩ
SEE TABLE 2 FOR CAPACITOR SELECTION.
MAX3222E MAX3232E
18
Maxim Integrated
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
_____________________________________Typical Operating Circuits (continued)
EN
23
R5OUT
15
R4OUT
16
R3OUT
17
R2OUT
18
R1OUT
19
R2OUTB
20
R1OUTB
21
TTL/CMOS
OUTPUTS
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
R5IN 8
*C3 CAN BE RETURNED TO EITHER VCC 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
VCC
C4
0.1µF
C3*
0.1µF
C1
0.1µF
C2
0.1µF
26
+3.3V
CBYPASS
MAX3241E
EN
13
R3OUT
18
R2OUT
20
R1OUT
21
R1OUTB
16
LOGIC
OUTPUTS
5kΩ
5kΩ
5kΩ
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
VCC
0.1µF
C3*
0.1µF
0.1µF
0.1µF
26
MBAUD 15
T5IN
17
T4IN
19
T5OUT 12
T4OUT 10
SHDN 14
T4
T5
CBYPASS
+3.3V
MAX3237E
Maxim Integrated
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
5kΩ
5kΩ
5kΩ
5kΩ
5kΩ
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
20
Maxim Integrated
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers
Selector Guide
PART
NO. OF
DRIVERS/
RECEIVERS
LOW-POWER
SHUTDOWN
GUARANTEED
DATA RATE
(bps)
MAX3222E 2/2 ✔250k
MAX3232E 2/2 — 250k
MAX3237E
(Normal) 5/3 ✔250k
MAX3237E
(MegaBaud) 5/3 ✔1M
MAX3241E 3/5 ✔250k
MAX3246E 3/5 ✔250k
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.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)
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
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
†
+
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.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
20 TQFN T2055+5 20-0140 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 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
Chip Information
PROCESS: BICMOS
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
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 qualified
part to Ordering Information, corrected capacitor in Typical Operating Circuits 1, 19
Revision History
22 Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications 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.
© 2010 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.
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MAX3222ECAP+ MAX3222ECUP+ MAX3222ECWN+ MAX3222EEAP+ MAX3222EEUP+ MAX3222EEWN+
MAX3232ECAE+ MAX3232ECPE+ MAX3232ECTE+ MAX3232ECUP+ MAX3232ECWE+ MAX3232EEAE+
MAX3232EEPE+ MAX3232EEUP+ MAX3232EEWE+ MAX3237ECAI+ MAX3237EEAI+ MAX3241ECAI+
MAX3241ECWI+ MAX3241EEAI+ MAX3241EEUI+ MAX3222ECUP+G071 MAX3222EEUP+G071
MAX3232ECUP+G071 MAX3232EEUP+G071 MAX3222ECUP+TG071 MAX3222EEUP+TG071
MAX3232ECUP+TG071 MAX3232EEUP+TG071 MAX3222ECAP+T MAX3222ECPN+ MAX3222ECTP+
MAX3222ECTP+T MAX3222ECUP+T MAX3222ECWN+T MAX3222EEAP+T MAX3222EEPN+ MAX3222EETP+
MAX3222EETP+T MAX3222EEUP+T MAX3222EEWN+T MAX3232ECAE+T MAX3232ECTE+T MAX3232ECUE+
MAX3232ECUE+T MAX3232ECUP+T MAX3232ECWE+T MAX3232EEAE+T MAX3232EETE+ MAX3232EETE+T
MAX3232EEUE+ MAX3232EEUE+T MAX3232EEUP+T MAX3232EEWE+T MAX3237ECAI+T MAX3237EEAI+T
MAX3241ECAI+T MAX3241ECTJ+ MAX3241ECTJ+T MAX3241ECUI+ MAX3241ECUI+T MAX3241ECWI+T
MAX3241EEAI+T MAX3241EEUI+T MAX3241EEWI+ MAX3241EEWI+T