MAX3323EEUE+T ,±15kV ESD-Protected, RS-232 Transceivers for Multidrop Applicationsapplications with low powerControlrequirements, high data-rate capabilities, andenhanced electrosta ..
MAX3325EAI ,3V dual RS-232 transceiver with LCD supply and contrast controller.ApplicationsPDAs and Palmtop ComputersTOP VIEWHandy TerminalsC2+ 1 28 C1+GPS ReceiversC2- 2 27 V+Ha ..
MAX3325EAI ,3V dual RS-232 transceiver with LCD supply and contrast controller.FeaturesThe MAX3325 integrates a two-transmitter, two-receiver' +3.0V to +3.6V Single-Supply Operat ..
MAX333ACAP ,Precision, Quad, SPDT, CMOS Analog SwitchMAX333A19-0189; Rev 1; 6/99Precision, Quad, SPDT, CMOS Analog Switch_______________
MAX333ACAP ,Precision, Quad, SPDT, CMOS Analog SwitchELECTRICAL CHARACTERISTICS—Dual Supplies(GND = 0V, V+ = +15V, V- = -15V, T = +25°C, unless otherwis ..
MAX333ACAP+ ,Precision, Quad, SPDT, CMOS Analog SwitchMAX333A19-0189; Rev 1; 6/99Precision, Quad, SPDT, CMOS Analog Switch_______________
MAX697CWE+ ,Microprocessor Supervisory CircuitsApplicationsMAX69613 LLIN4● Computers GND● Controllers12 N.C.BATT ON 5● Intelligent Instruments● Cr ..
MAX697CWE+T ,Microprocessor Supervisory CircuitsFeatures● Adjustable Low-Line Monitor and Power-Down ResetThe MAX696/MAX697 supervisory circuits re ..
MAX697EWE ,Microprocessor Supervisory CircuitsELECTRICAL CHARACTERISTICS
(Vcc = full operating range, VBATT = 2.8V, TA 2 25°C, unless otherwis ..
MAX697EWE ,Microprocessor Supervisory CircuitsFeatures
. Adjustable Low Line monitor and Power Down
Reset
. Power OK/Reset Time Delay
. ..
MAX697EWE+ ,Microprocessor Supervisory CircuitsElectrical Characteristics(V = full operating range, V = 2.8V, T = +25°C, unless otherwise noted.)C ..
MAX698 ,Low-Cost Power On Reset ICElectrical Characteristics(V = +5V, T = +25°C, unless otherwise noted.)CC APARAMETER CONDITIONS MIN ..
MAX3322EEUP-MAX3322EEUP+-MAX3322EEUP+T-MAX3323EEUE+-MAX3323EEUE+T
±15kV ESD-Protected, RS-232 Transceivers for Multidrop Applications
General DescriptionThe MAX3322E/MAX3323E 3.0V to 5.5V powered
EIA/TIA-232 and V.28/V.24 communications interfaces
are designed for multidrop applications with low power
requirements, high data-rate capabilities, and
enhanced electrostatic discharge (ESD) protection. All
RS-232 inputs and outputs are protected to ±15kV
using the IEC 1000-4-2 Air-Gap Discharge method,
±8kV using the IEC 1000-4-2 Contact Discharge
method, and ±15kV using the Human Body Model.
The MAX3322E/MAX3323E have pin-selectable
5kΩ/high-impedance RS-232 receivers. These devices
are capable of receiving data in high-impedance mode.
In multidrop applications, one receiver has a 5kΩinput
resistance, while the other receivers are high imped-
ance to ensure the RS-232 standard is observed. Logic
control permits selection of the functional mode: high
impedance or RS-232 standard load. The transmitters
are enabled by logic control to allow the multiplexing of
the inputs to a single UART.
A proprietary low-dropout transmitter output stage
enables true RS-232 performance from a 3.0V to 5.5V
supply with a dual charge pump. The charge pump
requires only four small 0.1µF capacitors for operation
from a 3.3V supply. The MAX3322E/MAX3323E are
capable of running at data rates up to 250kbps while
maintaining RS-232-compliant output levels. The
MAX3322E/MAX3323E have a unique VLpin that allows
operation in mixed-logic voltage systems. Both input
and output logic levels are pin programmable through
the VLpin.
The MAX3322E is a 2Tx/2Rx device for hardware hand-
shaking in standard RS-232 mode, and the MAX3323E
is a 1Tx/1Rx, required in most multidrop applications.
The MAX3322E is offered in a space-saving TSSOP
package. The MAX3323E is offered in 16-pin DIP and
space-saving TSSOP packages.
ApplicationsBar-Code Scanners
Video Security
Industrial Data Acquisition
Data Splitters
FeaturesPin-Selectable 5kΩ/High-Impedance Receivers Transmitter Outputs Three-Stated by Logic
ControlVLPin for Compatibility with Mixed Voltage
Systems 1Tx/1Rx (MAX3323E) or 2Tx/2Rx (MAX3322E)
Versions 250kbps Data Rate1µA Low-Power ShutdownHigh ESD 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 Discharge
MAX3322E/MAX3323E
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
Pin Configurations
Ordering Information19-2667; Rev 1; 1/03
Typical Operating Circuit and Functional Diagram appear
at end of data sheet.
MAX3322E/MAX3323E
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
ABSOLUTE MAXIMUM RATINGSStresses 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.
All Voltages Referenced to GND
VCC, VL....................................................................-0.3V to +6V
V+ (Note 1)....................................................(VCC- 0.3V) to +7V
V- (Note 1)................................................................+0.3V to -7V
V+ + |V-| (Note 1).................................................................+13V
Input Voltages
TIN_, RENABLE, TXENABLE, SHDN.....................-0.3V to +6V
RIN_..................................................................................±25V
Output Voltages
TOUT_............................................................................±13.2V
ROUT_........................................................-0.3V to (VL+ 0.3V)
Short-Circuit Duration TOUT_ to GND........................Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin DIP (derate 10.5mW/°C above +70°C)............842mW
16-Pin TSSOP (derate 9.4mW/°C above +70°C)........755mW
20-Pin TSSOP(derate 11mW/°C above +70°C)..........879mW
Operating Temperature Range
MAX3322E/MAX3323E...................................-40°C to +85°C
Junction Temperature.....................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
DC ELECTRICAL CHARACTERISTICS(VCC= 3.0V to 5.5V, VL= 1.65V to 5.5V, C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µF, C2 = C3 = C4 = 0.33µF, tested at +5V
Note 1:V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
MAX3322E/MAX3323E
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
DC ELECTRICAL CHARACTERISTICS (continued)(VCC= 3.0V to 5.5V, VL= 1.65V to 5.5V, C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µF, C2 = C3 = C4 = 0.33µF, tested at +5V
TIMING CHARACTERISTICS(VCC= 3.0V to 5.5V, VL= 1.65V to 5.5V, C1–C4 = 0.1µF, tested at +3.3V ±10%; C1 = 0.047µF, C2 = C3 = C4 = 0.33µF, tested at +5V
Note 2:Guaranteed by design. Not production tested.
MAX3322E/MAX3323E
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
Typical Operating Characteristics(VCC= 3.3V, VL= 3.3V, C1–C4 = 0.1µF, TA= +25°C.)
Detailed DescriptionThe MAX3322E/MAX3323E are RS-232 transceivers for
multidrop applications (i.e., multiple-receiver operation).
The devices are pin selectable between standard RS-232
operation with 5kΩinput resistance receivers or high-
input-impedance receivers. Receivers of the MAX3322E/
MAX3323E remain active in both modes of operation. In
multidrop applications, a selected receiver is set at a 5kΩ
input resistance, while the others are high-input imped-
ance, maintaining RS-232 standards. Logic control per-
mits selection of the functional mode: high impedance or
normal load. The transmitters are enabled by logic control
to allow transmission-line sharing.
The logic supply input (VL) controls the levels of the
system’s I/O and works from 1.65V to 5.5V, providing
compatibility with lower microprocessor I/O voltages.
The transmitters are inverting level translators that con-
vert CMOS logic levels into RS-232-compatible levels.
They guarantee 250kbps with loads of RL= 3kΩand CL
= 1000pF. The transmitters are enabled or disabled
(three-stated) by the logic control TXENABLE, which
manages transmission-line sharing in multidrop applica-
tions. When TXENABLE is high, the transmitter is
enabled. When TXENABLE is low, the transmitter is put
in high-impedance state. The receivers can be used in
two conditions, selectable by the logic control RENABLE.
When RENABLE is high, the internal 5kΩresistor is con-
nected across receiver input and ground. When
RENABLE is low, the receiver input is high impedance,
while maintaining receiving capability.
In shutdown mode, all transmitter and receiver outputs
are three-stated, receiver inputs are in high impedance,
the charge pump is turned off, V+ decays to VCC, and
V- decays to ground. ESD protection structures are
incorporated in all pins to protect against ESD events
encountered during handling and assembly. The
receiver inputs and the transmitter outputs have ±15kV
ESD structure implementation.
MAX3322E/MAX3323E
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
MAX3322E/MAX3323E
Dual Charge-Pump Voltage ConverterThe MAX3322E/MAX3323Es’ internal power supply con-
sists of a regulated dual charge pump that provides out-
put voltages of +5.5V (doubling charge pump) and
-5.5V (inverting charge pump), regardless of the input
voltage (VCC), over a +3.0V to +5.5V range. The charge
pumpsoperate in a discontinuous mode: if the output
voltages are less than 5.5V, the charge pumps are
enabled; if the output voltages exceed 5.5V, the charge
pumps are disabled. Each charge pump requires a fly-
ing capacitor (C1, C2) and reservoir capacitor (C3, C4)
to generate the V+ and V- supplies. Because supply
voltages can vary from +3V up to +5.5V, the selection
of the capacitor values depends on the VCCvalue.
Table 2 shows minimum capacitor values.
RS-232 TransmittersThe transmitters are inverting level translators that con-
vert CMOS-logic levels to 5.0V EIA/TIA-232 levels. The
transmitters are enabled or disabled (three-stated) by
the logic control TXENABLE, which manages transmis-
sion-line sharing in multidrop applications. When
TXENABLE is high, the transmitter is enabled. When
TXENABLE is low, the transmitter is put in a high-
impedance state (see Table 1).
The MAX3322E/MAX3323Es’ transmitters guarantee a
250kbps data rate with worst-case loads of 3kΩin par-
allel with 1000pF, providing compatibility with PC-to-PC
communication software (such as LapLink™).
Transmitters can be paralleled to drive multiple
receivers or mice. Figure 3 shows a complete system
connection.
RS-232 ReceiversMAX3322E/MAX3323E receivers convert RS-232 sig-
nals to CMOS-logic output levels. The unique feature of
the receivers is the switchable input resistance. The
receiver input resistance can be 5kΩor high imped-
ance. These two conditions are selectable by the logic
control RENABLE. When RENABLE is high, the 5kΩ
resistor is connected across the receiver input and
ground. When RENABLE is low, the receiver input is
high impedance, maintaining receiving capability. This
feature permits the design of multidrop applications,
which observe RS-232 interface standards.
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop ApplicationsFigure 1. Transmitter Propagation-Delay Timing
Figure 2. Receiver Propagation-Delay Timing
High-input impedance is guaranteed from -13.0V to
+13.0V, when the receiver is in high-input-impedance
mode. The receiver is able to withstand the RS-232
maximum input voltage of ±25V.
Shutdown ModeSupply current falls to less than 10µA when the
MAX3322E/MAX3323E are placed in shutdown mode
(logic low). When in shutdown mode, the devices’
charge pumps are turned off, V+ decays to VCC, V- is
pulled to ground, the transmitter outputs and the
receiver outputs are disabled (high impedance), and
the receiver inputs are in high impedance (Table 1).
The device enters shutdown when VLor VCCis absent.
The time required to exit shutdown is typically 50µs, as
shown in Figure 4. Connect SHDNto VCCif shutdown
mode is not used.
Logic Supply InputUnlike other RS-232 interface devices, in which the
receiver outputs swing between 0 and VCC, the
MAX3322E/MAX3323E feature a separate logic supply
input (VL) that sets VOUTfor the receiver outputs and
sets thresholds for the transmit and shutdown inputs.
This feature allows a great deal of flexibility in interfac-
ing to many types of systems with different logic levels.
Connect this input to the host logic supply (1.65V ≤VL5.5V).
±15kV ESD ProtectionTo protect the MAX3322E/MAX3323E against ESD,
transmitters and receivers have extra protection against
static electricity to protect the device up to ±15kV. The
ESD structures withstand high ESD in all states: normal
operation, shutdown, and powered down. ESD protec-
tion can be tested in various ways; the transmitter and
receiver pins are characterized for protection to the fol-
lowing limits:±15kV using the Human Body Model±8kV using the IEC 1000-4-2 Contact Discharge
method±15kV using the IEC 1000-4-2 Air-Gap method
Note:ESD performance depends on many conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body ModelFigure 5 shows the Human Body Model, and Figure 6
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 inter-
est, which is then discharged into the test device
through a 1.5kΩresistor.
MAX3322E/MAX3323E
±15kV ESD-Protected, RS-232 Transceivers for
Multidrop Applications
