MAX3232CSE ,3.0V to 5.5V / Low-Power / up to 1Mbps / True RS-232 Transceivers Using Four 0.1F External CapacitorsFeaturesThe MAX3222/MAX3232/MAX3237/MAX3241 trans- ' Low Supply Current:300µA (MAX3222/MAX3232/MAX3 ..
MAX3232CSE ,3.0V to 5.5V / Low-Power / up to 1Mbps / True RS-232 Transceivers Using Four 0.1F External CapacitorsApplicationsV+ 3 16 GNDNotebook, Subnotebook, and Palmtop ComputersC1- T1OUT4 15High-Speed ModemsMA ..
MAX3232CSE ,3.0V to 5.5V / Low-Power / up to 1Mbps / True RS-232 Transceivers Using Four 0.1F External Capacitorsfeatures a 1µA shutdown mode' Pin Compatible with Industry-Standard MAX232that reduces power consum ..
MAX3232CSE ,3.0V to 5.5V / Low-Power / up to 1Mbps / True RS-232 Transceivers Using Four 0.1F External CapacitorsFeaturesThe MAX3222/MAX3232/MAX3237/MAX3241 trans- ' Low Supply Current:300µA (MAX3222/MAX3232/MAX3 ..
MAX3232CSE ,3.0V to 5.5V / Low-Power / up to 1Mbps / True RS-232 Transceivers Using Four 0.1F External CapacitorsMAX3222/MAX3232/MAX3237/MAX3241*19-0273; Rev 5; 3/993.0V to 5.5V, Low-Power, up to 1Mbps, True RS-2 ..
MAX3232CSE+ ,3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232 Transceivers Using Four 0.1µF External CapacitorsELECTRICAL CHARACTERISTICS(V = +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T to T , unless otherwis ..
MAX667CSA ,+5V/Programmable Low-Dropout Voltage Regulatorfeatures include a low-Shutdown Mode: 0.2µA Typ Quiescent Currentvoltage detector to indicate powe ..
MAX667CSA ,+5V/Programmable Low-Dropout Voltage RegulatorELECTRICAL CHARACTERISTICS(GND = 0V, V = +9V, V = +5V, C1 = 10m F, unless otherwise noted.)IN OUT T ..
MAX667CSA ,+5V/Programmable Low-Dropout Voltage RegulatorMAX667 MAX66719-3894; Rev 3; 10/94+5V/Programmable Low-DropoutVoltage Regulator_______________
MAX667CSA ,+5V/Programmable Low-Dropout Voltage Regulatorapplications where the input voltages______________Ordering Informationare above +3.5V. Choose the ..
MAX667CSA. ,+5V/Programmable Low-Dropout Voltage RegulatorMAX667 MAX66719-3894; Rev 3; 10/94+5V/Programmable Low-DropoutVoltage Regulator_______________
MAX667CSA+ ,+5V Programmable, Low-Dropout Voltage Regulatorfeatures include a low-Shutdown Mode: 0.2µA Typ Quiescent Currentvoltage detector to indicate powe ..
MAX3232+CSE-MAX3232CPE-MAX3232CSE-MAX3232CUE-MAX3232CWE-MAX3232EPE-MAX3232ESE-MAX3232EUE-MAX3232EWE-MAX3237CAI-MAX3237EAI-MAX3241CAI-MAX3241CAI--MAX3241CUI-MAX3241CWI-MAX3241EAI-MAX3241EWI
3.0V to 5.5V / Low-Power / up to 1Mbps / True RS-232 Transceivers Using Four 0.1F External Capacitors
_______________General DescriptionThe MAX3222/MAX3232/MAX3237/MAX3241 trans-
ceivers have a proprietary low-dropout transmitter out-
put stage enabling true RS-232 performance from a
3.0V to 5.5V supply with a dual charge pump. The
devices require only four small 0.1µF external charge-
pump capacitors. The MAX3222, MAX3232, and
MAX3241 are guaranteed to run at data rates of
120kbps while maintaining RS-232 output levels. The
MAX3237 is guaranteed to run at data rates of 250kbps
in the normal operating mode and 1Mbps in the
MegaBaud™ operating mode, while maintaining RS-232
output levels.
The MAX3222/MAX3232 have 2 receivers and 2
drivers. The MAX3222 features a 1µA shutdown mode
that reduces power consumption and extends battery
life in portable systems. Its receivers remain active in
shutdown mode, allowing external devices such as
modems to be monitored using only 1µA supply cur-
rent. The MAX3222 and MAX3232 are pin, package,
and functionally compatible with the industry-standard
MAX242 and MAX232, respectively.
The MAX3241 is a complete serial port (3 drivers/
5 receivers) designed for notebook and subnotebook
computers. The MAX3237 (5 drivers/3 receivers) is ideal
for fast modem applications. Both these devices feature
a shutdown mode in which all receivers can remain
active while using only 1µA supply current. Receivers R1
(MAX3237/MAX3241) and R2 (MAX3241) have extra out-
puts in addition to their standard outputs. These extra
outputs are always active, allowing external devices
such as a modem to be monitored without forward bias-
ing the protection diodes in circuitry that may have VCC
completely removed.
The MAX3222, MAX3237, and MAX3241 are available
in space-saving TSSOP and SSOP packages.
________________________ApplicationsNotebook, Subnotebook, and Palmtop Computers
High-Speed Modems
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
____________________________FeaturesLow Supply Current:
300µA (MAX3222/MAX3232/MAX3241)
500µA (MAX3237)Guaranteed Data Rate:
120kbps (MAX3222/MAX3232/MAX3241)
250kbps (MAX3237—Normal Operation)
1Mbps (MAX3237—MegaBaud Operation)1µA Low-Power Shutdown with Receivers Active
(MAX3222/MAX3237/MAX3241)Flow-Through Pinout (MAX3237)Meets EIA/TIA-232 Specifications Down to 3.0VGuaranteed Mouse Driveability (MAX3241)Pin Compatible with Industry-Standard MAX232
(MAX3232)
Pin Compatible with Industry-Standard MAX242
(MAX3222)Guaranteed Slew Rate:
6V/µs (MAX3222/MAX3232/MAX3237/MAX3241)
24V/µs (MAX3237—MegaBaud Operation)
MAX3222/MAX3232/MAX3237/MAX3241*
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors19-0273; Rev 5; 3/99
MegaBaud is a trademark of Maxim Integrated Products.
Typical Operating Circuits appear at end of data sheet.
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VCC= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
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.
Note 1:V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
VCC...........................................................................-0.3V to +6V
V+ (Note 1)...............................................................-0.3V to +7V
V- (Note 1)................................................................+0.3V to -7V
V+ + V- (Note 1)...................................................................+13V
Input Voltages
T_IN, SHDN, EN...................................................-0.3V to +6V
MBAUD...................................................-0.3V to (VCC+ 0.3V)
R_IN.................................................................................±25V
Output Voltages
T_OUT...........................................................................±13.2V
R_OUT....................................................-0.3V to (VCC+ 0.3V)
Short-Circuit Duration
T_OUT....................................................................Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin Plastic DIP (derate 10.53mW/°C above +70°C)...842mW
16-Pin Narrow SO (derate 8.70mW/°C above +70°C)....696mW
16-Pin Wide SO (derate 9.52mW/°C above +70°C)........762mW
16-Pin TSSOP (derate 6.7mW/°C above +70°C).............533mW
18-Pin Plastic DIP (derate 11.11mW/°C above +70°C)..889mW
18-Pin SO (derate 9.52mW/°C above +70°C)..............762mW
20-Pin SSOP (derate 8.00mW/°C above +70°C).........640mW
20-Pin TSSOP (derate 7.0mW/°C above +70°C).............559mW
28-Pin SO (derate 12.50mW/°C above +70°C).....................1W
28-Pin SSOP (derate 9.52mW/°C above +70°C).........762mW
28-Pin TSSOP (derate 8.7mW/°C above +70°C).............696mW
Operating Temperature Ranges
MAX32_ _C_ _.....................................................0°C to +70°C
MAX32_ _E_ _ .................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10sec).............................+300°C
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
TIMING CHARACTERISTICS—MAX3222/MAX3232/MAX3241(VCC= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
ELECTRICAL CHARACTERISTICS (continued)(VCC= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
__________________________________________Typical Operating Characteristics(VCC= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, TA= +25°C, unless otherwise noted.)
TIMING CHARACTERISTICS—MAX3237(VCC= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
Note 2:MAX3222/MAX3232/MAX3241: C1–C4 = 0.1µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested at 5.0V ±10%.
MAX3237: C1–C4 = 0.1µF tested at 3.3V ±5%; C1–C4 = 0.22µF tested at 3.3V ±10%; C1 = 0.047µF, C2–C4 = 0.33µF tested
at 5.0V ±10%.
Note 3:Transmitter input hysteresis is typically 250mV.
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
_____________________________Typical Operating Characteristics (continued)(VCC= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, TA= +25°C, unless otherwise noted.)
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
______________________________________________________________Pin Description
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
_______________Detailed Description
Dual Charge-Pump Voltage ConverterThe MAX3222/MAX3232/MAX3237/MAX3241’s internal
power supply consists of a regulated dual charge pump
that provides output voltages of +5.5V (doubling charge
pump) and -5.5V (inverting charge pump), regardless of
the input voltage (VCC) over the 3.0V to 5.5V range. The
charge pumps operate in a discontinuous mode; if the
output voltages are less than 5.5V, the charge pumps
are enabled, and if the output voltages exceed 5.5V, the
charge pumps are disabled. Each charge pump
requires a flying capacitor (C1, C2) and a reservoir
capacitor (C3, C4) to generate the V+ and V- supplies.
RS-232 TransmittersThe transmitters are inverting level translators that con-
vert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
The MAX3222/MAX3232/MAX3241 transmitters guaran-
tee a 120kbps data rate with worst-case loads of 3kΩin
parallel with 1000pF, providing compatibility with PC-to-
PC communication software (such as LapLink™).
Typically, these three devices can operate at data rates
of 235kbps. Transmitters can be paralleled to drive multi-
ple receivers or mice.
The MAX3222/MAX3237/MAX3241’s output stage is
turned off (high impedance) when the device is in shut-
down mode. When the power is off, the MAX3222/
MAX3232/MAX3237/MAX3241 permit the outputs to be
driven up to ±12V.
The transmitter inputs do not have pull-up resistors.
Connect unused inputs to GND or VCC.
MAX3237 MegaBaud OperationIn normal operating mode (MBAUD = GND), the
MAX3237 transmitters guarantee a 250kbps data rate
with worst-case loads of 3kΩin parallel with 1000pF.
This provides compatibility with PC-to-PC communica-
tion software, such as Laplink™.
For higher speed serial communications, the MAX3237
features MegaBaud operation. In MegaBaud operating
mode (MBAUD = VCC), the MAX3237 transmitters guar-
antee a 1Mbps data rate with worst-case loads of 3kΩin
parallel with 250pF for 3.0V < VCC < 4.5V. For 5V ±10%
operation, the MAX3237 transmitters guarantee a 1Mbps
data rate into worst-case loads of 3kΩin parallel with
1000pF.
Figure 1. Slew-Rate Test Circuits
LapLink is a trademark of Traveling Software.
MAX3222/MAX3232/MAX3237/MAX3241
3.0V to 5.5V, Low-Power, up to 1Mbps, True RS-232ransceivers Using Four 0.1µF External Capacitors
RS-232 ReceiversThe receivers convert RS-232 signals to CMOS-logic out-
put levels. The MAX3222/MAX3237/MAX3241 receivers
have inverting three-state outputs. In shutdown, the
receivers can be active or inactive (Table 1).
The complementary outputs on the MAX3237 (R1OUTB)
and the MAX3241 (R1OUTB, R2OUTB) are always active,
regardless of the state of ENor SHDN. This allows for
Ring Indicator applications without forward biasing other
devices connected to the receiver outputs. This is ideal
for systems where VCCis set to 0V in shutdown to
accommodate peripherals, such as UARTs (Figure 2).
MAX3222/MAX3237/MAX3241
Shutdown ModeSupply current falls to less than 1µA in shutdown mode
(SHDN= low). When shut down, the device’s charge
pumps are turned off, V+ is pulled down to VCC, V- is
pulled to ground, and the transmitter outputs are dis-
abled (high impedance). The time required to exit shut-
down is typically 100µs, as shown in Figure 3. ConnectSHDN to VCCif the shutdown mode is not used. SHDN
has no effect on R_OUT or R_OUTB.
MAX3222/MAX3237/MAX3241
Enable ControlThe inverting receiver outputs (R_OUT) are put into a
high-impedance state when ENis high. The complemen-
tary outputs R1OUTB and R2OUTB are always active,
regardless of the state of ENand SHDN(Table 1). EN
has no effect on T_OUT.
__________Applications Information
Capacitor SelectionThe 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, refer to
Table 2 for required capacitor values. Do not use values
lower than those listed in Table 2. Increasing the capaci-
tor values (e.g., by a factor of 2) reduces ripple on the
transmitter outputs and slightly reduces power consump-
tion. 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, and C4, 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 exces-
sively with temperature. If in doubt, use capacitors with a
higher nominal value. The capacitor’s equivalent series
resistance (ESR), which usually rises at low tempera-
tures, influences the amount of ripple on V+ and V-.
