MAXIM MAX3222E, MAX3232E, MAX3237E, MAX3241E, MAX3246E User Manual

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 protected 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 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 opera­tion from a +3.3V supply. Each device guarantees opera­tion 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-232­compliant output levels.

The MAX3222E/MAX3232E have two receivers and two
transmitters. The MAX3222E features a 1µA shutdown
mode that reduces power consumption in battery-pow­ered 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 func­tionally 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 shut­down mode in which all receivers remain active, while
consuming only 1µA (MAX3241E/MAX3246E) or 10nA
(MAX3237E).

The MAX3222E, MAX3232E, and MAX3241E are avail­able in space-saving SO, SSOP, TQFN and TSSOP pack­ages. The MAX3237E is offered in an SSOP package.
The MAX3246E is offered in the ultra-small 6 x 6 UCSP™
package.

Applications

Battery-Powered Equipment Printers
Cell Phones Smart Phones
Cell-Phone Data Cables xDSL Modems
Notebook, Subnotebook,

and Palmtop Computers

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

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,

Up to 1Mbps, True RS-232 Transceivers

________________________________________________________________ Maxim Integrated Products 1

19-1298; Rev 10; 1/06

_______________Ordering Information

Ordering Information continued at end of data sheet.

*Dice are tested at TA= +25°C, DC parameters only.

**EP = Exposed paddle.

Pin Configurations, Selector Guide, and Typical Operating
Circuits appear at end of data sheet.

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

PIN­PACKAGE

PKG

CODE

MAX3222ECTP

20 Thin QFN­EP** (5mm x
5mm)

T2055-5

MAX3222ECUP

20 TSSOP —

MAX3222ECAP

20 SSOP —

MAX3222ECWN

18 Wide SO —

MAX3222ECPN

—

MAX3222EC/D

Dice* —

MAX3222EETP

20 Thin QFN­EP** (5mm x
5mm)

T2055-5

MAX3222EEUP

20 TSSOP —

MAX3222EEAP

20 SSOP —

MAX3222EEWN

18 Wide SO —

MAX3222EEPN

—

MAX3232ECAE

16 SSOP —

MAX3232ECWE

16 Wide SO —

MAX3232ECPE

—

MegaBaud and UCSP are trademarks of Maxim Integrated
Products, Inc.

†

Covered by U.S. Patent numbers 4,636,930; 4,679,134;
4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and
other patents pending.

0°C to +70°C

0°C to +70°C

0°C to +70°C

0°C to +70°C

0°C to +70°C 18 Plastic DIP

0°C to +70°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C 18 Plastic DIP

0°C to +70°C

0°C to +70°C

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

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, TA= T

MIN

to T

MAX

, 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.

VCCto 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 (MAX3241E)................-0.3V to (V

CC

+ 0.3V)

Short-Circuit Duration, T_OUT to GND.......................Continuous

Continuous Power Dissipation (T

A

= +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-Lead Thin QFN (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

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 recom­mended 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

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

V

CC

= +5.0V 2.4

V

Transmitter Input Hysteresis 0.5 V

T_IN, EN, SHDN

MAX3222E, MAX3232E,
MAX3241E, MAX3246E

±1

Input Leakage Current

T_IN, SHDN, MBAUD MAX3237E (Note 5) 9 18

µA

RECEIVER OUTPUTS

Output Leakage Current

R_OUT (MAX3222E/MAX3237E/MAX3241E/
MAX3246E), EN = V

CC

, receivers disabled

µA

Output-Voltage Low

I

OUT

= 1.6mA (MAX3222E/MAX3232E/MAX3241E/

MAX3246E), I

OUT

= 1.0mA (MAX3237E)

0.4 V

SHDN = R_IN = GND, T_IN = GND or VCC (MAX3237E)

±0.01

±0.05 ±10

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,

Up to 1Mbps, True RS-232 Transceivers

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 3, 4)

PARAMETER CONDITIONS

UNITS

Output-Voltage High I

OUT

= -1.0mA

0.6

0.1

V

RECEIVER INPUTS

Input Voltage Range -25

V

VCC = +3.3V 0.6 1.1

Input Threshold Low TA = +25°C

V

CC

= +5.0V 0.8 1.5

V

VCC = +3.3V 1.5 2.4

Input Threshold High TA = +25°C

V

CC

= +5.0V 2.0 2.4

V

Input Hysteresis 0.5 V

Input Resistance TA = +25°C 3 5 7 kΩ

TRANSMITTER OUTPUTS

Output Voltage Swing

All transmitter outputs loaded with 3kΩ to ground
(Note 6)

±5

V

Output Resistance VCC = 0, transmitter output = ±2V

Ω

Output Short-Circuit Current

mA

Output Leakage Current

V

C C

= 0 or + 3.0V to + 5.5V , V

OU T

= ± 12V , tr ansm i tter s

d i sab l ed ( M AX 3222E /M AX 3232E /M AX 3241E /M AX 3246E )

µA

MOUSE DRIVABILITY (MAX3241E)

Transmitter Output Voltage

T1IN = T2IN = GND, T3IN = V

CC

, T3OUT loaded with
3kΩ to GND, T1OUT and T2OUT loaded with 2.5mA
each

±5 V

ESD PROTECTION

Human Body Model

IEC 1000-4-2 Air-Gap Discharge (except MAX3237E)

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

IEC1000-4-2 Air-Gap Discharge

T_IN, R_IN, R_OUT, EN, SHDN,
MBAUD

MAX3237E

IEC1000-4-2 Contact Discharge ±8

kV

MIN TYP MAX

VCC -

300 50k

VCC -

±5.4

±15

±15

±15

±15

+25

±60

±25

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers

4 _______________________________________________________________________________________

TIMING CHARACTERISTICS—MAX3237E

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, TA= T

MIN

to T

MAX

, 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 T

A

= +25°C.

Note 7: Transmitter skew is measured at the transmitter zero crosspoints.

PARAMETER CONDITIONS

MIN

TYP

MAX

UNITS

RL = 3kΩ, CL = 1000pF, one transmitter switching,
MBAUD = GND

VCC = +3.0V to +4.5V, RL = 3kΩ, CL = 250pF,
one transmitter switching, MBAUD = V

CC

Maximum Data Rate

V

CC

= +4.5V to +5.5V, RL = 3kΩ, CL = 1000pF,

one transmitter switching, MBAUD = V

CC

kbps

t

PHL

Receiver Propagation Delay R_IN to R_OUT, CL = 150pF

t

PLH

µs

Receiver Output Enable Time Normal operation

µs

Receiver Output Disable Time Normal operation

µs

| t

PHL

- t

PLH

|, MBAUD = GND

Transmitter Skew (Note 7)

| t

PHL

- t

PLH

|, MBAUD = V

CC

ns

Receiver Skew | t

PHL

- t

PLH

|

ns

MBAUD = GND 6 30

CL = 150pF
to 1000pF

MBAUD = V

CC

VCC = +3.3V,

-3.0V to +3.0V,
T

A

= +25°C

C

L

= 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= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 3, 4)

PARAMETER

CONDITIONS

UNITS

TA = T

MIN

to T

MAX

(MAX3222E/MAX3232E/
MAX3241E) (Note 6)

Maximum Data Rate

R

L

= 3kΩ,

C

L

= 1000pF,
one transmitter
switching T

A

= + 25°C ( M AX 3246E )

kbps

t

PHL

Receiver Propagation Delay

t

PLH

Receiver input to receiver output,
C

L

= 150pF

µs

Receiver Output Enable Time Normal operation (except MAX3232E)

ns

Receiver Output Disable Time Normal operation (except MAX3232E)

ns

Transmitter Skew

(Note 7)

ns

Receiver Skew

ns

Transition-Region Slew Rate

V

C C

= + 3.3V , TA = + 25°C ,

R

L

= 3kΩ to 7kΩ , m easur ed

fr om + 3.0V to - 3.0V or - 3.0V to

630

V/µs

|t

|t

SYMBOL

- t

PHL

PLH

- t

PHL

PLH

|

|50

C

= 150pF

L

to 1000pF

+ 3.0V , one tr ansm i tter sw i tchi ng

MIN TYP MAX

250

250

0.15

0.15

200

200

100

RL = 3kΩ to 7kΩ,
+3.0V to -3.0V or

250

1000

1000

0.15

0.15

2.6

2.4

100

50

24 150

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,

Up to 1Mbps, True RS-232 Transceivers

_______________________________________________________________________________________ 5

-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 + C

L

5

3

1

-1

-3

-5

V

OUT+

V

OUT-

-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)

V

OUT-

V

OUT

+

FOR DATA RATES UP TO 250kbps
1 TRANSMITTER 250kbps
4 TRANSMITTERS 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3kΩ + C

L

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 = V

CC

)

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 + C

L

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 3kΩ and 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

V

OUT+

V

OUT-

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

0 1000 2000 3000 4000 5000

MAX3241E

SLEW RATE vs. LOAD CAPACITANCE

MAX3237E toc05

LOAD CAPACITANCE (pF)

SLEW RATE (V/µs)

-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

V

OUT+

V

OUT-

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

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VCC= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and CL, TA = +25°C, unless otherwise noted.)

0

20

60

40

80

100

0

MAX3237E

TRANSMITTER SKEW vs. LOAD CAPACITANCE

(MBAUD = V

CC

)

MAX3237E toc12

LOAD CAPACITANCE (pF)

1000 1500500 2000

TRANSMITTER SKEW (ns)

|t

PLH

- t

PHL

|
1 TRANSMITTER AT 500kbps
4 TRANSMITTERS AT 1/16 DATA RATE
ALL TRANSMITTERS LOADED
WITH 3kΩ + C

L

-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)

V

OUT-

V

OUT

+

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

V

OUT-

V

OUT+

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 + C

L

0

10

20

30

50

40

60

70

0

MAX3237E

SLEW RATE vs. LOAD CAPACITANCE

(MBAUD = V

CC

)

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 + C

L

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 + C

L

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,

Up to 1Mbps, True RS-232 Transceivers

_______________________________________________________________________________________ 7

*These pins have an active positive feedback resistor internal to the MAX3237E, allowing unused inputs to be left unconnected.

Pin Description

PIN

MAX3222E MAX3232E

TQFN

SO/DIP/

16-PIN

NAME

FUNCTION

19

1—— — 13* 23

B3 EN

Receiver Enable. Active
low.

1

2

12 2828

F3

Positive Terminal of
Voltage-Doubler Charge­Pump Capacitor

20

3

23 2727

F1 V+

+5.5V Generated by the
Charge Pump

2

413 4 25 24

F4

Negative Terminal of
Voltage-Doubler Charge­Pump Capacitor

3

524 5 1 1

E1

Positive Terminal of
Inverting Charge-Pump
Capacitor

4

635 6 3 2

D1

Negative Terminal of
Inverting Charge-Pump
Capacitor

5

746 7 4 3

C1 V-

-5.5V Generated by the
Charge Pump

6, 15

8,

5,

5, 6, 7,

10, 12

9,

10,

11

6,
7,

8

F6, E6,

D6

RS-232 Transmitter
Outputs

7, 14

9,

6,

A4, A5,
A6, B6,

C6

RS-232 Receiver Inputs

8, 13

10,

7,

12,

15

18, 20,

21

13,
14,
15,

C2, B1,
A1, A2,

A3

TTL/CMOS Receiver
Outputs

10, 11

11,

13,

14

17*, 19*,
22*, 23*,

24*

12,
13,

14

10,
11,

E3, E2,

D2

TTL/CMOS Transmitter
Inputs

MAX3241E

SO/

TSSOP/

DIP

SSOP

1

2

3

4

5

6

7

8, 17

15

9, 16

14

10, 15

13

12, 13 8, 9 10, 11

12

TQFN

SSOP/

TSSOP

16

15

7, 14 8, 17

12

8, 13 9, 16 8, 9, 11 4–8 1–5

11

9, 12

10

20-PIN
TSSOP

MAX3237E

SSOP/

SO

15–19

17, 18

QFN

22

28

27

23

29

30

31

12

MAX3246E

C1+

C1-

C2+

C2-

T_OUT

R_IN

R_OUT

T_IN

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

/MAX3246E

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 Transceivers

8 _______________________________________________________________________________________

Pin Description (continued)

PIN

MAX3222E MAX3232E

TQFN

SO/DIP/

16-PIN

FUNCTION

16

18

15 18 2 25

F5

Ground

17

19

16 19 26 26

F2

+3.0V to +5.5V Supply
Voltage

18

20 — — — 14* 22

B2

Shutdown Control. Active
low.

9, 12

——

1, 10,

——

25,

C3, D3, B4,

C4, D4, E4,

B5, C5, D5,

E5

No Connection. For
MAX3246E, these
locations are not
populated with solder
bumps.

—

——— — 15* —

—

MegaBaud Control Input.
Connect to GND for
normal operation; connect
to VCC for 1Mbps
transmission rates.

—

——— — 16

20,

21

—

Noninverting
Complementary Receiver
Outputs. Always active.

EP

—

—— — —

—

Exposed Paddle. Solder
the exposed paddle to
the ground alone or leave
unconnected.

MAX3241E

SO/
DIP

16

TSSOP/

SSOP

TQFN

13

SSOP/

TSSOP

20-PIN
TSSOP

MAX3237E

SSOP/

SO/

TSSOP

QFN

24

MAX3246E

NAME

GND

17

18

— 11, 14

—

—

—

14

EP

11, 20

26

21

9, 16,

32

—

19, 20

EP

V

CC

SHDN

N.C.

MBAUD

R_OUTB

GND