MAX3233ECWP+TG36 ,±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsELECTRICAL CHARACTERISTICS(V = +3.0V to +3.6V for MAX3233E, V = +4.5V to +5.5V for MAX3235E; T = T ..
MAX3233ECWP-T ,±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsFeaturesThe MAX3233E/MAX3235E are EIA/TIA-232 and V.28/V.24 ♦ ESD Protection for RS-232 I/O Pinscom ..
MAX3233EEWP ,【15kV ESD-Protected, 1レA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsELECTRICAL CHARACTERISTICS(V = +3.0V to +3.6V for MAX3233E, V = +4.5V to +5.5V for MAX3235E; T = T ..
MAX3233EEWP/T ,±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsApplications GNDT2INSubnotebook and Palmtop Computers 4 17T1INV-Cellular Phones516Battery-Powered E ..
MAX3233EEWP+G36 ,±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal Capacitorsfeatures, high data-rate capabilities, and±8kV—IEC 1000-4-2, Contact Dischargeenhanced electrostati ..
MAX3233EEWP+T ,±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsELECTRICAL CHARACTERISTICS(V = +3.0V to +3.6V for MAX3233E, V = +4.5V to +5.5V for MAX3235E; T = T ..
MAX6730UTRD3 ,Single-/Dual-/Triple-Voltage µP Supervisory Circuits with Independent Watchdog OutputApplications● Multivoltage SystemsWDO NMIPUSHBUTTON● Telecom/Networking EquipmentMRSWITCH● Computer ..
MAX6730UTRD3 ,Single-/Dual-/Triple-Voltage µP Supervisory Circuits with Independent Watchdog OutputElectrical Characteristics(V 1 = V 2 = +0.8V to +5.5V, T = -40°C to +85°C, unless otherwise noted. ..
MAX6731UTTD3+ ,Single-/Dual-/Triple-Voltage µP Supervisory Circuits with Independent Watchdog Outputfeatures Down to +0.63V (MAX6734/MAX6735 Only)significantly improves system reliability and accurac ..
MAX6733UTSVD3-T ,Vcc1: 2.925 V, Vcc2: 1.575 V, active timeout period: 140 ms-280 ms, single/dual/triple-voltage mP supervisor circuit with independent watchdog outputfeatures significantly improves systemVoltages Down to +0.63V (MAX6734/MAX6735 Only)reliability and ..
MAX6734KASYD3-T ,Vcc1: 2.925 V, Vcc2: 2.188 V, active timeout period: 140 ms-280 ms, single/dual/triple-voltage mP supervisor circuit with independent watchdog outputApplicationsonly the V 1 threshold suffix after the “UT.” Insert the resetCCMultivoltage Systems ti ..
MAX6735KASYD3-T ,Vcc1: 2.925 V, Vcc2: 2.188 V, active timeout period: 140 ms-280 ms, single/dual/triple-voltage mP supervisor circuit with independent watchdog outputELECTRICAL CHARACTERISTICS(V 1 = V 2 = +0.8V to +5.5V, T = -40°C to +85°C, unless otherwise noted. ..
MAX3233ECWP+-MAX3233ECWP+TG36-MAX3233ECWP-T-MAX3233EEWP/T-MAX3233EEWP+G36-MAX3233EEWP+T-MAX3233EEWP+TG36-MAX3235EEWP+TG36
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal Capacitors
________________General DescriptionThe MAX3233E/MAX3235E are EIA/TIA-232 and V.28/V.24
communications interfaces with automatic shutdown/
wake-up features, high data-rate capabilities, and
enhanced electrostatic discharge (ESD) protection. All
transmitter outputs and receiver inputs are protected to
±15kV using IEC 1000-4-2 Air-Gap Discharge, to ±8kV
using IEC 1000-4-2 Contact Discharge, and to ±15kV
using the Human Body Model. The MAX3233E operates
from a +3.3V supply; the MAX3235E operates from +5.0V.
All devices achieve a 1μA supply current using Maxim’s
revolutionary AutoShutdown Plus™ feature. These
devices automatically enter a low-power shutdown
mode when the following two conditions occur: either
the RS-232 cable is disconnected or the transmitters of
the connected peripherals are inactive, and the UART
driving the transmitter inputs is inactive for more than
30 seconds. They turn on again when they sense a
valid transition at any transmitter or receiver input.
AutoShutdown Plus saves power without changes to
the existing BIOS or operating system.
The MAX3233E/MAX3235E have internal dual charge
pumps requiring no external capacitors. Both trans-
ceivers have a proprietary low-dropout transmitter out-
put stage that enables true RS-232 performance from a
+3.0V to +3.6V supply for the MAX3233E or a +4.5V to
+5.5V supply for the MAX3235E. These devices are
guaranteed to operate up to 250kbps. Both are avail-
able in space-saving 20-pin wide SO or plastic DIP
packages.
________________________ApplicationsSubnotebook and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Handheld Equipment
Peripherals
Embedded Systems
____________________________FeaturesESD Protection for RS-232 I/O Pins
±15kV—Human Body Model
±8kV—IEC 1000-4-2, Contact Discharge
±15kV—IEC 1000-4-2, Air-Gap DischargeLatchup Free1μA Supply CurrentAutoShutdown Plus—1997 EDN Magazine
Innovation of the YearSingle-Supply Operation
+3.0V to +3.6V (MAX3233E)
+4.5V to +5.5V (MAX3235E)250kbps Guaranteed Data Rate6V/μs Guaranteed Slew RateMeets EIA/TIA-232 Specifications Down to 3.0V
(MAX3233E)Internal Charge-Pump Capacitors
MAX3233E/MAX3235E
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal Capacitors19-1473; Rev 2; 8/04
PART
MAX3233ECWP0°C to +70°C
TEMP RANGEPIN-PACKAGE20 SO
AutoShutdown Plus is a trademark of Maxim Integrated Products, Inc.
_______________Ordering Information
Ordering Information continued at end of data sheet.MAX3233E
MAX3235ER2OUTR2IN
T2OUT
GND
C2-
C2+
C1-
C1+
INVALID
T2IN
T1IN
FORCEON
R1OUT
T1OUT
R1IN
VCC
FORCEOFF
CHARGE
PUMP
SO/DIP
Pin Configuration/ Functional Diagram
Typical Operating Circuit appears at end of data sheet.MAX3233ECPP0°C to +70°C20 Plastic DIP
MAX3233EEPP-40°C to +85°C20 Plastic DIP
MAX3233EEWP-40°C to +85°C20 SO
†Co7;
4,7erpg.
MAX3233E
/MAX3235E
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VCC= +3.0V to +3.6V for MAX3233E, VCC= +4.5V to +5.5V for MAX3235E; TA= TMINto TMAX, unless otherwise noted. Typical val-
ues 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 toabsolute maximum rating conditions for extended periods may affect device reliability.
VCCto GND (MAX3233E).........................................-0.3V to +4V
VCCto GND (MAX3235E).........................................-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, FORCEON, FORCEOFFto GND....................-0.3V to +6V
R_IN to GND...................................................................±25V
Output Voltages
T_OUT to GND.............................................................±13.2V
R_OUT, INVALIDto GND......................-0.3V to (VCC+ 0.3V)
Short-Circuit Duration
T_OUT to GND......................................................Continuous
Continuous Power Dissipation (TA= +70°C)
Wide SO (derate 10mW/°C above +70°C)..................800mW
Plastic DIP (derate 11.11mW/°C above +70°C).........889mW
Operating Temperature Ranges
MAX323_EC_P...................................................0°C to +70°C
MAX323_EE_P................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) (Note 2)...................+300°C
Note 1:V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
Note 2:Maximum reflow temperature is +220°C.
FORCEON = GND, FORCEOFF= VCC,
all R_IN idle, all T_IN idle= +25°C
CONDITIONS357Input Resistance0.5Input Hysteresis
1.82.4V1.52.4Input Threshold High
0.81.3V0.61.0Input Threshold Low-25+25Input Voltage RangeVCC- 0.6 VCC- 0.1Output Voltage High0.4Output Voltage Low110Supply Current, Shutdown110Supply Current,
AutoShutdown Plus±0.01±1
Transmitter Input Hysteresis V0.52.4Input Logic Threshold High0.31Supply Current,
AutoShutdown Plus Disabled0.8Input Logic Threshold Low
UNITSMINTYPMAXSYMBOLPARAMETERFORCEOFF= GND= +25°C
T_IN, FORCEON, FORCEOFF
FORCEON = FORCEOFF= VCC, no load
T_IN, FORCEON, FORCEOFF
IOUT= -1.0mA
IOUT= 1.6mA
Input Leakage Current
DC CHARACTERISTICS(VCC= 3.3V for MAX3233E, VCC= 5.0V for MAX3235E, TA= +25°C.)
LOGIC INPUTS AND RECEIVER OUTPUTS
RECEIVER INPUTS= +25°CVCC= 5.0V, MAX3235E
VCC= 3.3V, MAX3233E
VCC= 5.0V, MAX3235E
VCC= 3.3V, MAX3233E
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsT_IN, FORCEON,
FORCEOFFVCC= 5.0V, MAX3235E
VCC= 3.3V, MAX3233E
MAX3233E
/MAX3235E
ELECTRICAL CHARACTERISTICS (continued)(VCC= +3.0V to +3.6V for MAX3233E, VCC= +4.5V to +5.5V for MAX3235E; TA= TMINto TMAX, unless otherwise noted. Typical val-
ues are at TA= +25°C.)
CONDITIONS30010MOutput Resistance±5±5.4Output Voltage Swing
UNITSMINTYPMAXSYMBOLPARAMETERFigure 3a153060tAUTOSHDNReceiver or Transmitter Edge to
Transmitters Shut Down100tWUReceiver or Transmitter Edge to
Transmitters Enabled1tINVHReceiver Positive or Negative
Threshold to INVALIDHighVCC - 0.6INVALID, Output Voltage High0.4INVALIDOutput Voltage Low-0.30.3Receiver Input Threshold to
INVALIDOutput Low
-2.7V2.7Receiver Input Threshold to
INVALIDOutput High
±15R_IN, T_OUTkV
±15
±25
Output Leakage Current
±60mAOutput Short-Circuit Current
VCC= V+ = V- = 0, transmitter outputs = ±2V
All transmitter outputs loaded with 3kΩto
ground
Figure 3b (Note 3)
Figure 3b (Note 3)
Figure 3b
IOUT= -1.0mA
IOUT= -1.6mA
Figure 3a
Human Body Model
VOUT= ±12V
transmitters
disabled
IEC1000-4-2 Contact Discharge
IEC1000-4-2 Air Discharge
VCC= 0 or +4.5V to
5.5V (MAX3235E)
VCC= 0 or +3.0V to
3.6V (MAX3233E)
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal Capacitors±25
MAX3233E
MAX3235E50μs70tINVLReceiver Positive or Negative
Threshold to INVALIDLowFigure 3b
TRANSMITTER OUTPUTS
ESD PROTECTION
AutoShutdown PLUS(FORCEON = GND, FORCEOFF= VCC)
Positive threshold
Negative threshold
Note 3:A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds.
MAX3233E
/MAX3235E
TIMING CHARACTERISTICS (VCC= +3.0V to +3.6V for MAX3233E, VCC= +4.5V to +5.5V for MAX3235E; TA= TMINto TMAX, unless otherwise noted. Typical val-
ues are at TA= +25°C.)
Note 2:A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds.
Note 3:Transmitter skew is measured at the transmitter zero cross points.CL= 150pF
to 2500pF= 150pF
to 1000pF
R_IN to R_OUT, = 150pF= 3kΩ, CL= 1000pF,
one transmitter switching
VCC= 3.3V (MAX3233E),
VCC= 5.0V (MAX3235E), = +25°C,= 3kΩto 7kΩ,
measured from +3V to -3V
or -3V to +3V
Normal operation
Normal operation
(Note 4)
CONDITIONS100nstPHL
kbps250Maximum Data Rate
Receiver Propagation Delay
V/μs3030
Transition-Region Slew Rate200Receiver Output Enable Time200Receiver Output Disable Time150⏐tPHL- tPLH ⏐Transmitter Skew180⏐tPHL- tPLH ⏐Receiver Skew
UNITSMINTYPMAXSYMBOLPARAMETERVOUT-
VOUT+
TRANSMITTER OUTPUT VOLTAGE vs.
LOAD CAPACITANCE
3233E/35Etoc01
LOAD CAPACITANCE (pF)
(V20001000300040005000
OPERATING SUPPLY CURRENT
vs. LOAD CAPACITANCEAX3233E/35E toc02
LOAD CAPACITANCE (pF)
(m
TRANSMITTER 1 AT DATA RATE
TRANSMITTER 2 AT 1/16 DATA RATE
20kbps
120kbps
250kbps10002000300040005000
SLEW RATE vs.
LOAD CAPACITANCE3233E/35Etoc01
LOAD CAPACITANCE (pF)
(VSLEW RATE -
SLEW RATE +
Note 4:Transmitter skew is measured at the transmitter zero crosspoints.
__________________________________________Typical Operating Characteristics(VCC= +3.3V for MAX3233E, VCC= +5.0V for MAX3235E; 250kbps data rate; all transmitters loaded with 3kΩand CL; TA= +25°C,
unless otherwise noted.)
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal Capacitors250tPLH
MAX3233E
MAX3235E
MAX3233E
MAX3235EMAX3235E
MAX3233E
MAX3233E
/MAX3235E
______________________________________________________________Pin DescriptionTTL/CMOS Receiver Outputs
FUNCTIONPINNAME11, 12
R2OUT
Invalid Signal Detector Output, active low. A logic high indicates that a valid RS-232
level is present on a receiver.
T2INTTL/CMOS Transmitter OutputsINVALID
T1OUTRS-232 Transmitter Outputs
FORCEONForce-On Input, active high. Drive high to override AutoShutdown Plus, keeping
transmitters and receivers active (FORCEOFFmust be high) (Table 1).
R1INRS-232 Receiver Outputs
C1+Positive terminal of the internal voltage-doubling charge-pump capacitor. Leave
unconnected or connect to an external 0.1μF capacitor. See Charge PumpSection.
VCCSupply Voltage (MAX3233E = +3.3V, MAX3235E = +5.0V)
FORCEOFFForce-Off Input, active low. Drive low to shut down transmitters, receivers, and charge
pump. This overrides AutoShutdown Plus and FORCEON (Table 1).+5.5V generated by the charge pump. Do not connect.
C1-Negative terminal of the internal voltage-doubling charge-pump capacitor. Leave
unconnected or connect to an external 0.1μF capacitor. See Charge PumpSection.
C2+Positive terminal of the internal inverting charge-pump capacitor. Do not connect.
C2-Negative terminal of the internal inverting charge-pump capacitor. Do not connect.-5.5V generated by the charge pump. Do not connect.
GNDGround
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsR1OUTT1INT2OUTR2IN
_______________Detailed Description
Dual Charge-Pump Voltage Converter The MAX3233E/MAX3235E’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), with no external capaci-
tors. The charge pump operates in discontinuous
mode: if the output voltages are less than 5.5V, the
charge pump is enabled; if the output voltages exceed
5.5V, the charge pump is disabled.
RS-232 Transmitters The transmitters are inverting level translators that
convert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
The devices 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 paralleled to
drive multiple receivers. Figure 1 shows a complete
system connection.
When FORCEOFFis driven to ground or when the Auto-
Shutdown Plus circuitry senses that all receiver and
transmitter inputs are inactive for more than 30sec, the
transmitters are disabled and the outputs go into a high-
impedance state. When powered off or shut down, the
outputs can be driven to ±12V. The transmitter inputs
do not have pull-up resistors. Connect unused inputs to
GND or VCC.
RS-232 Receivers The receivers convert RS-232 signals to CMOS-logic
output levels. They feature inverting outputs that always
remain active (Table 1).
The MAX3233E/MAX3235E feature an INVALIDoutput
that is enabled low when no valid RS-232 voltage levels
have been detected on all receiver inputs. Because
INVALIDindicates the receiver input’s condition, it is
independent of FORCEON and FORCEOFFstates
(Figures 2 and 3).
AutoShutdown Plus ModeThe devices achieve a1μAsupplycurrentwith Maxim’s
AutoShutdown Plus feature, which operates when
FORCEOFFis high and a FORCEON is low. When these
devices do not sense a valid signal transition on any
receiver or transmitter input for 30sec, the on-board
charge pumps are shut down, reducing supply current
to 1μA. This occurs if the RS-232 cable is disconnected,
or if the connected peripheral transmitters are turned off
and the UART driving the transmitter inputs is inactive.
The system turns on again when a valid transition is
MAX3233E
/MAX3235E
±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual RS-232 Transceivers with Internal CapacitorsMAX3233E
MAX3235E
I/O
CHIP
WITH
UART
CPURS-232
POWER-
MANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER
FORCEOFF
FORCEON
INVALID
Figure 1. Interface Under Control of PMU
LapLink is a trademark of Traveling Software.
+0.3V
-0.3V
INVALID
R_IN
INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR
AT LEAST 80μs.80µs
TIMER
+2.7V
-2.7V
INVALID
R_IN
INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN ABOVE +2.7V OR BELOW
-2.7V FOR 1μs.
80µs
TIMER
Figure 2a. INVALIDFunctional Diagram, INVALIDLow
Figure 2b. INVALIDFunctional Diagram, INVALIDHigh
