MAX3232E ,±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 TransceiversApplicationsModel. The logic and receiver I/O pins of the MAX3237EBattery-Powered Equipmentare prot ..
MAX3232ECAE ,+-15kV ESD-protected, down to 10nA, 3.0V to5.5V, up to 1Mbps, true RS-232 transceiver.FeaturesThe MAX3222E/MAX3232E/MAX3237E/MAX3241E are ESD Protection for RS-232 I/O Pins3V-powered ..
MAX3232ECAE+ ,±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 TransceiversFeaturesThe MAX3222E/MAX3232E/MAX3237E/MAX3241E/ ♦♦ For Space-Constrained
MAX3232ECAE+T ,±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 TransceiversEVALUATION KIT AVAILABLEMAX3222E/MAX3232E/MAX3237E/ MAX3241E/MAX3246E±15kV ESD-Protected, Down to 1 ..
MAX3232ECAE-T ,±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 TransceiversFeaturesThe MAX3222E/MAX3232E/MAX3237E/MAX3241E/ ♦♦ For Space-Constrained
MAX3232ECD ,3-V to 5.5-V Multichannel RS-232 Line Driver/Receiver With +/-15kV IEC ESD Protection 16-SOIC 0 to 70Electrical Characteristics — Device ....... 512 Device and Documentation Support........ 136.6
MAX6690MEE ,2C Accurate Remote/Local Temperature Sensor with SMBus Serial InterfaceApplicationsDXP 3 14 SMBCLKDesktop Computers WorkstationsDXN 4 MAX6690 13 N.C.Notebook Computers Te ..
MAX6690MEE+ ,2°C Accurate Remote/Local Temperature Sensor with SMBus Serial InterfaceFeaturesThe MAX6690 is a precise digital thermometer that ♦ High Accuracy ±2°C (max) from +70°C to ..
MAX6690MEE+T ,2°C Accurate Remote/Local Temperature Sensor with SMBus Serial InterfaceELECTRICAL CHARACTERISTICS(V = +3V to +5.5V, T = -55°C to +125°C, unless otherwise noted. Typical v ..
MAX6692MUA ,Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature AlarmsApplicationsVCC10kΩ EACHDesktop ComputersNotebook ComputersDXPSDA DATAServersMAX6648 CLOCKSCLKMAX66 ..
MAX6692MUA ,Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature AlarmsELECTRICAL CHARACTERISTICS(V = 3.0V to 5.5V, T = -55°C to +125°C, unless otherwise specified. Typic ..
MAX6692MUA ,Precision SMBus-Compatible Remote/Local Temperature Sensors with Overtemperature AlarmsApplicationsVCC10kΩ EACHDesktop ComputersNotebook ComputersDXPSDA DATAServersMAX6648 CLOCKSCLKMAX66 ..
MAX3232E
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V, Up to 1Mbps, True RS-232 Transceivers
AVAILABLE
EVALUATION KIT AVAILABLE
General DescriptionThe 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
ApplicationsBattery-Powered Equipment
Cell PhonesSmart 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
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
PARTTEMP RANGEPIN-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
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= TMINto 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.
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 (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.
PARAMETERCONDITIONSMINTYPMAXUNITS
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 INPUTSInput 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,SHDNMAX3222E, MAX3232E,
MAX3241E, MAX3246E ±0.01 ±1 Input Leakage Current
T_IN, SHDN, MBAUD MAX3237E (Note 5) 9 18
μA
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= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 3, 4)
PARAMETERCONDITIONSMINTYPMAXUNITS
RECEIVER OUTPUTSOutput 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 INPUTSInput 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 OUTPUTSOutput 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 PROTECTIONHuman 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
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= TMINto 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 atthe supply rails.
PARAMETERCONDITIONSMINTYPMAXUNITSRL = 3kΩ, CL = 1000pF, one transmitter switching,
MBAUD = GND250
VCC = +3.0V to +4.5V, RL = 3kΩ, CL = 250pF,
one transmitter switching, MBAUD = VCC1000Maximum Data Rate
VCC = +4.5V to +5.5V, RL = 3kΩ, CL = 1000pF,
one transmitter switching, MBAUD = VCC1000
kbps
tPHL0.15Receiver Propagation DelayR_IN to R_OUT, CL = 150pFtPLH0.15µs
Receiver Output Enable TimeNormal operation2.6µs
Receiver Output Disable TimeNormal operation2.4µs
|tPHL - tPLH|, MBAUD = GNDTransmitter Skew (Note 7)|tPHL - tPLH|, MBAUD = VCC100ns
Receiver Skew|tPHL - tPLH|50ns
MBAUD = GND630CL = 150pF
to 1000pF
MBAUD = VCC24150
VCC = +3.3V,
RL = 3kΩ to 7kΩ,
+3.0V to -3.0V or
-3.0V to +3.0V,
TA = +25°CCL = 150pF to 2500pF,
MBAUD = GND430
V/µsTransition-Region Slew Rate
TIMING CHARACTERISTICS—MAX3222E/MAX3232E/MAX3241E/MAX3246E(VCC= +3V to +5.5V, C1–C4 = 0.1µF, TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 3, 4)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSTA = TMIN to TMAX
(MAX3222E/MAX3232E/
MAX3241E) (Note 6)
250Maximum Data Rate
RL = 3kΩ,
CL = 1000pF,
one transmitter
switchingTA = + 25°C ( M AX 3246E ) 250
kbps
tPHL0.15Receiver Propagation DelaytPLH
Receiver input to receiver output,
CL = 150pF0.15µs
Receiver Output Enable TimeNormal operation (except MAX3232E)200ns
Receiver Output Disable TimeNormal operation (except MAX3232E)200ns
Transmitter Skew|tPHL - tPLH|(Note 7)100ns
Receiver Skew|tPHL - tPLH|50ns
Transition-Region Slew RateC C = + 3.3V , TA = + 25°C ,
RL = 3kΩ to 7kΩ , m easur ed
fr om + 3.0V to - 3.0V or - 3.0V to3.0V , one tr ansm i tter sw i tchi ng
CL = 150pF
to 1000pF630V/µs
MAX3222E/MAX3232E/MAX3237E/
MAX3241E/MAX3246E
10002000300040005000
MAX3222E/MAX3232E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCEMAX3237E toc01
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
T1 TRANSMITTING AT 250kbps
T2 TRANSMITTING AT 15.6kbps
VOUT+
VOUT-10002000300040005000
MAX3222E/MAX3232E
SLEW RATE vs. LOAD CAPACITANCEMAX3237E toc02
LOAD CAPACITANCE (pF)
SLEW RATE (V/
+SLEW
FOR DATA RATES UP TO 250kbps
-SLEW20001000300040005000
MAX3222E/MAX3232E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCEMAX3237E 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
MAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = GND)MAX3237E toc07
TRANSMITTER OUTPUT VOLTAGE (V)
FOR DATA RATES UP TO 250kbps
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3kΩ + CL
VOUT+
VOUT-10001500500200025003000
MAX3246E toc07A
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 CAPACITANCEMAX3237E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCE (MBAUD = VCC)
MAX3237E toc08
TRANSMITTER OUTPUT VOLTAGE (V)
1 TRANSMITTER AT FULL DATA RATE
4 TRANSMITTERS AT 1/16 DATA RATE
3kΩ + CL LOAD, EACH OUTPUT
2Mbps1.5Mbps
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.)10002000300040005000
MAX3241E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCEMAX3237E to04
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
VOUT+
VOUT-20001000300040005000
MAX3241E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCEMAX3237E toc06
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
120kbps
20kbps
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps10002000300040005000
MAX3241E
SLEW RATE vs. LOAD CAPACITANCEMAX3237E toc05
LOAD CAPACITANCE (pF)
SLEW RATE (V/
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.)
MAX3237E
TRANSMITTER SKEW vs. LOAD CAPACITANCE
(MBAUD = VCC)
MAX3237E toc12
LOAD CAPACITANCE (pF)
TRANSMITTER SKEW (ns)|tPLH - tPHL|
1 TRANSMITTER AT 500kbps
4 TRANSMITTERS AT 1/16 DATA RATE
ALL TRANSMITTERS LOADED
WITH 3kΩ + CL-6
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)MAX3237E SUPPLY CURRENT
vs. SUPPLY VOLTAGE (MBAUD = GND)
MAX3237E toc14
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3kΩ AND 1000pF
MAX3246E
TRANSMITTER OUTPUT VOLTAGE
vs. LOAD CAPACITANCEMAX3237E toc15
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
VOUT-
VOUT+
MAX3246E
SLEW RATE vs. LOAD CAPACITANCEMAX3237E toc16
LOAD CAPACITANCE (pF)
SLEW RATE (V/
SR+
SR-
MAX3246E
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCEMAX3237E toc17
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps
250kbps
120kbps
20kbps
MAX3237E
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = GND)MAX3237E toc09
LOAD CAPACITANCE (pF)
SLEW RATE (V/
SR+
SR-
1 TRANSMITTER AT 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3kΩ + CL
MAX3237E
SLEW RATE vs. LOAD CAPACITANCE
(MBAUD = VCC)MAX3237E toc10
LOAD CAPACITANCE (pF)
SLEW RATE (V/
-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
MAX3237E
SUPPLY CURRENT vs. LOAD CAPACITANCE
WHEN TRANSMITTING DATA (MBAUD = GND)LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
120kbps
20kbps
1 TRANSMITTER AT 20kbps, 120kbps, 250kbps
4 TRANSMITTERS AT 15.6kbps
ALL TRANSMITTERS LOADED
WITH 3kΩ + CL
MAX3222E/MAX3232E/MAX3237E/
MAX3241E/MAX3246E
±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
MAX3222EMAX3232EMAX3241E
TQFNSO/
DIP
TSSOP/
SSOPTQFN
SO/DIP/
SSOP/
16-PIN
TSSOP
20-PIN
TSSOP
MAX3237ESSOP/
SO/
TSSOP
TQFNMAX3246ENAMEFUNCTION11———13*2322B3ENReceiver Enable. Active
low.221612282828F3C1+
Positive Terminal of
Voltage-Doubler Charge-
Pump Capacitor331523272727F1V++5.5V Generated by the
Charge Pump44134252423F4C1-
Negative Terminal of
Voltage-Doubler Charge-
Pump Capacitor552451129E1C2+
Positive Terminal of
Inverting Charge-Pump
Capacitor663563230D1C2-
Negative Terminal of
Inverting Charge-Pump
Capacitor774674331C1V--5.5V Generated by the
Charge Pump
6, 158,8, 175,7, 148, 175, 6, 7,
10, 12
10,
F6, E6,T_OUTRS-232 Transmitter
Outputs
7, 149,9, 166,8, 139, 168, 9, 114–81–5
A4, A5,
A6, B6,
R_INRS-232 Receiver Inputs
8, 1310,10, 157,9, 1212,
18, 20,15–19
13,
14,
15,
17, 18
C2, B1,
A1, A2,
R_OUTTTL/CMOS Receiver
Outputs
10, 1111,12, 138, 910, 1113,
17*, 19*,
22*, 23*,
24*
12,
13,
10,
11,
E3, E2,T_INTTL/CMOS Transmitter
Inputs
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
MAX3222EMAX3232EMAX3241E
TQFNSO/
DIP
TSSOP/
SSOPTQFN
SO/DIP/
SSOP/
16-PIN
TSSOP
20-PIN
TSSOP
MAX3237ESSOP/
SO/
TSSOP
TQFNMAX3246ENAMEFUNCTION161813151822524F5GNDGround1719141619262626F2VCC+3.0V to +5.5V Supply
Voltage1820———14*2221B2SHDNShutdown Control. Active
low.
9, 12—11, 14——1, 10,
11, 20——
9, 16,
25,
C3, D3, B4,
C4, D4, E4,
B5, C5, D5,
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.————1620,19, 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).
MAX3222E/MAX3232E/MAX3237E/
MAX3241E/MAX3246E
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 VCCrange. 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 OperationFor 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
MAX3237Etransmitters 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 ENhigh 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_ INR_ OUT
C2-
C2+
C1-
C1+VCCC1
C2
0.1µF
VCC
T_ OUTT_ IN
GND7kΩ150pF
MAX3222E
MAX3232E
MAX3237E
MAX3241E
MAX3246E
5kΩ
R_ INR_ OUT
C2-
C2+
C1-
C1+VCCC1
C2
0.1µF
VCC
T_ OUTT_ IN
GND3kΩ1000pF
(2500pF, MAX3237E only)
MINIMUM SLEW-RATE TEST CIRCUITMAXIMUM SLEW-RATE TEST CIRCUITFigure 1. Slew-Rate Test Circuits
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 TransceiversMAX3222E/MAX3232E/MAX3237E/
MAX3241E/MAX3246E
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 TransceiversThe complementary outputs on the MAX3237E/
MAX3241E(R_OUTB) are always active, regardless of the
state of ENor 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 VCCdrops 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 SHDNto VCCif shutdown mode is
not used. SHDNhas no effect on R_OUT or R_OUTB
(MAX3237E/MAX3241E).
±15kV ESD ProtectionAs 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
5kΩ
UART
VCC
T1IN
LOGIC
TRANSITION
DETECTOR
R1INR1OUT
THREE-STATED
EN = VCC
SHDN = GND
VCCµP
PREVIOUS
RS-232
UART
PROTECTION
DIODE
PROTECTION
DIODE
SHDN = GND
VCC
VCC
GND
5kΩ
a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROMA 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
2V/div
VCC = 3.3V
C1–C4 = 0.1µF
Figure 3. Transmitter Outputs Recovering from Shutdown or
Powering Up
MAX3222E/MAX3232E/MAX3237E/
MAX3241E/MAX3246E
±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
Up to 1Mbps, True RS-232 TransceiversESD 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
100pF
RC
1MΩ
RD
1500Ω
HIGH-
VOLTAGE
SOURCE
DEVICE-
UNDER-
TEST
Figure 4a. Human Body ESD Test Model
IP 100%
90%
36.8%
tRLTIME
tDL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
10%
AMPERES
Figure 4b. Human Body Model Current Waveform
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
150pF
RC
50MΩ to 100MΩ
RD
330Ω
HIGH-
VOLTAGE
SOURCE
DEVICE-
UNDER-
TEST
Figure 5a. IEC 1000-4-2 ESD Test Model
tr = 0.7ns to 1ns
30ns
60ns
100%
90%
10%
IPEAK
Figure 5b. IEC 1000-4-2 ESD Generator Current Waveform
Table 1. MAX3222E/MAX3237E/MAX3241E/
MAX3246E Shutdown and Enable Control
Truth TableSHDNEN
T_OUTR_OUT
R_OUTB
(MAX3237E/
MAX3241E)0High
impedanceActiveActive1High
impedance
High
impedanceActive0ActiveActiveActive1ActiveHigh
impedanceActive
MAX3222E/MAX3232E/MAX3237E/
MAX3241E/MAX3246E
