MAX3250EAI ,50V Isolated / 3.0V to 5.5V / 250kbps / 2 Tx/2 Rx / RS-232 TransceiverApplicationsR1OUT 2 27 C2-Industrial ControlR2OUT 3 26 GNDProgrammable Logic ControllerT1IN 4 25 FA ..
MAX3250EAI+ ,±50V Isolated, 3.0V to 5.5V, 250kbps, 2 Tx/2 Rx, RS-232 TransceiverGeneral Description Benefits and
MAX3250EAI+T ,±50V Isolated, 3.0V to 5.5V, 250kbps, 2 Tx/2 Rx, RS-232 TransceiverApplicationsR1OUT 2 27 C2-Industrial ControlR2OUT 3 26 GNDProgrammable Logic ControllerT1IN 4 25 FA ..
MAX325CPA ,Precision, Single-Supply, SPST Analog SwitchesFeaturesThe MAX323/MAX324/MAX325 are precision, dual, ' Low On-Resistance (R ), 60Ω max (33Ω typ)ON ..
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MAX325CSA ,Precision, Single-Supply, SPST Analog SwitchesGeneral Description ________
MAX691AEPE ,Microprocessor Supervisory CircuitsApplications______________Ordering InformationComputersControllersPART TEMP. RANGE PIN-PACKAGEMAX69 ..
MAX691AEPE+ ,Microprocessor Supervisory CircuitsElectrical Characteristics(MAX691A, MAX800L: V = +4.75V to +5.5V; MAX693A, MAX800M: V = +4.5V to +5 ..
MAX691AESE ,Microprocessor Supervisory CircuitsGeneral Description ________
MAX691AESE ,Microprocessor Supervisory CircuitsELECTRICAL CHARACTERISTICS(MAX691A, MAX800L: V = +4.75V to +5.5V, MAX693A, MAX800M: V = +4.5V to +5 ..
MAX691AESE+ ,Microprocessor Supervisory CircuitsApplications● ComputersPIN- PART TEMP RANGEPACKAGE● ControllersMAX691ACUE -0°C to +70°C 16 TSSOP● I ..
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MAX3250EAI
50V Isolated / 3.0V to 5.5V / 250kbps / 2 Tx/2 Rx / RS-232 Transceiver
General DescriptionThe MAX3250 is a 3.0V to 5.5V powered, ±50V isolated
EIA/TIA-232 and V.28/V.24 communications interface
with high data-rate capabilities. The MAX3250 is a dual
die part that operates with up to ±50V difference
between the RS-232 side and the logic side (ISOCOM
to GND). This makes the device ideal for operation in
noisy conditions with high common-mode voltages.
This feature prevents damage to the device if RS-232
lines are inadvertently short-circuited to a +24V or ±48V
power bus.
The MAX3250 is powered by a single 3V to 5.5V supply
on the logic side. Power is transferred from the logic
side to the isolated side by ±100V external capacitors.
The MAX3250 has two receivers (Rx) and two drivers
(Tx) and is guaranteed to run at data rates of 250kbps
while maintaining RS-232 output levels. The trans-
ceivers have a proprietary low-dropout transmitter out-
put stage, delivering true RS-232 performance from a
3V to 5.5V supply with a dual charge pump. The device
features a FAULTopen-drain output to signal an exces-
sive isolated-side voltage condition on any of the RS-
232 inputs. This output can drive an alarm LED or can
be monitored by the processor to prevent operation
under these conditions. The receiver outputs are high
impedance in shutdown, allowing multiple interfaces
(IrDA, RS-232, RS-485) to be connected to the same
UART.
The MAX3250 is available in a space-saving 28-pin
SSOP package.
ApplicationsIndustrial Control
Programmable Logic Controller
Point-of-Sale Equipment
PC-to-Router Connections
Diagnostic Ports
Telecom Equipment
Features±50V Isolation20µA Supply Current in Shutdown250kbps Guaranteed Data RateFAULT
OutputHigh-Impedance Transmitter and Receiver
Outputs in ShutdownSpace-Saving SSOP PackageInductorless/Transformerless Design Simplifies
EMI ComplianceLow-Cost Replacement for Opto-Isolated
TransceiversMeets EIA/TIA-232 Specifications Down to 3.0V
MAX3250
±50V Isolated, 3.0V to 5.5V,
250kbps, 2 Tx/2 Rx, RS-232 Transceiver
Ordering Information19-2443; Rev 1; 2/03
Typical Operating Circuit appears at end of data sheet.
Pin Configuration
MAX3250
±50V Isolated, 3.0V to 5.5V,
250kbps, 2 TX/2 RX, RS-232 Transceiver
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, Unless Otherwise Noted.
VCC...........................................................................-0.3V to +6V
ISOCOM...............................................................................±80V
ISOVCCto ISOCOM..................................................-0.3V to +6V
V+ to ISOCOM (Note 1)............................................-0.3V to +7V
V- to ISOCOM (Note 1)............................................+0.3V to -7V
V+ + |V-| (Note 1)...................................................................13V
Input Voltages
T_IN, SHDN...........................................................-0.3V to +6V
R_IN to ISOCOM...............................................................±25V
Output Voltages
T_OUT to ISOCOM........................................................±13.2V
R_OUT.....................................................-0.3V to (VCC+ 0.3V)FAULT....................................................................-0.3V to +6V
C1-, C2-......................................................-0.3V to (VCC+ 0.3V)
C1+, C2+, C3+, C3-, C4+, C4-
to ISOCOM......................................-0.3V to (ISOVCC+ 0.3V)
T_OUT Current..............30mA (continuous), 50mA (peak, 10µs)
R_IN Current..................30mA (continuous), 50mA (peak, 10µs)
ISOCOM Current...........30mA (continuous), 50mA (peak, 10µs)
Short-Circuit Duration T_OUT to ISOCOM.................Continuous
Continuous Power Dissipation (TA= +70°C)
28-Pin SSOP (derate 9.5mW/°C above +70°C)...........762mW
Operating Temperature Ranges
MAX3250CAI.....................................................0°C to +70°C
MAX3250EAI...................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS(VCC= 3.0V to 5.5V, see Typical Operating Circuitand Table 1 for capacitor values, ISOCOM = GND, TA= TMINto TMAX, unless oth-
Note 1:V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V.
MAX3250
±50V Isolated, 3.0V to 5.5V,
250kbps, 2 TX/2 RX, RS-232 Transceiver
ELECTRICAL CHARACTERISTICS (continued)(VCC= 3.0V to 5.5V, see Typical Operating Circuitand Table 1 for capacitor values, ISOCOM = GND, TA= TMINto TMAX, unless oth-
TIMING CHARACTERISTICS(VCC= 3.0V to 5.5V, see Typical Operating Circuitand Table 1 for capacitor values, ISOCOM = GND, TA= TMINto TMAX, unless oth-
Note 2:All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to device
ground, unless otherwise noted.
Note 3:Transmitter skew is measured at the transmitter zero crosspoints.
MAX3250
±50V Isolated, 3.0V to 5.5V,
250kbps, 2 TX/2 RX, RS-232 Transceiver
Typical Operating Characteristics(VCC= 3.3V, 250kbps data rate, see Typical Operating Circuitand Table 1 for capacitor values, all transmitters loaded with 3kΩandto ISOCOM, TA= +25°C, unless otherwise noted.)
MAX3250
±50V Isolated, 3.0V to 5.5V,
250kbps, 2 TX/2 RX, RS-232 Transceiver
MAX3250
±50V Isolated, 3.0V to 5.5V,
250kbps, 2 TX/2 RX, RS-232 Transceiver
Detailed DescriptionThe MAX3250 is a 3.0V to 5.5V powered, ±50V isolated
EIA/TIA-232 and V.28/V.24 communications interface
with high data-rate capabilities. The MAX3250 is a dual
die part that operates with up to ±50V difference
between the RS-232 side and the logic side (ISOCOM
to GND). This makes the device ideal for operation in
noisy conditions with high common-mode voltages.
This feature prevents damage to the device if RS-232
lines are inadvertently short-circuited to a +24V or ±48V
power bus.
The MAX3250 typically draws 15mA of supply current
when unloaded. Supply current drops to 20µA when
the device is placed in shutdown mode.
The MAX3250 has two receivers and two drivers and is
guaranteed to operate at data rates up to 250kbps. The
device features a FAULTopen-drain output to signal an
excessive isolated-side voltage condition on any of the
RS-232 inputs. This output can drive an alarm LED or can
be monitored by the processor to prevent operation
under these conditions. The receiver outputs are high
impedance in shutdown, allowing multiple interfaces
(IrDA, RS-232, RS-485) to be connected to the same
UART (Figure 1). The MAX3250 is a low-cost replacement
for opto-isolated transceivers.
Isolated Power SupplyThe MAX3250 drives a high-frequency square wave into
C1 and a complementary square wave into C2. These
Figure 1. Functional Diagram
