MAX3220BCAP ,3V to 5.5V, up to 250kbps true RS-232 transceiver with 4microA autoshutdown plus and power-on reset. Reset threshold 2.85V.Applications ______________Ordering InformationPalmtop ComputersPART* TEMP. RANGE PIN-PACKAGEPortab ..
MAX3220BEAP ,3V to 5.5V, up to 250kbps true RS-232 transceiver with 4microA autoshutdown plus and power-on reset. Reset threshold 2.85V.ELECTRICAL CHARACTERISTICS(V = 3V to 5.5V, C1–C4 = 0.1µF (tested at 3.3V ±10%), C1 = 0.047µF, C2–C4 ..
MAX3221 ,1µA Supply Current, True +3V to +5.5V RS-232 Transceivers with AutoShutdown™FeaturesThe MAX3221/MAX3223/MAX3243 achieve 1µA supply • Integrated Charge Pump Circuitry Simplifie ..
MAX3221 ,1µA Supply Current, True +3V to +5.5V RS-232 Transceivers with AutoShutdown™ApplicationsMAX3223EAP -40°C to +85°C 20 SSOP• Battery-Powered EquipmentMAX3223EUP -40°C to +85°C 2 ..
MAX3221CAE ,1A Supply Current / True +3V to +5.5V RS 232 Transceiver with AutoShutdownMAX3221/MAX3223/MAX3243*19-0306; Rev 6; 3/991µA Supply-Current, True +3V to +5.5VRS-232 Transceiver ..
MAX3221CAE+ ,+3V to +5.5V RS-232 Transceivers with AutoShutdownGeneral Description Benefits and
MAX6456UT29S+T ,µP Supervisors with Separate VCC Reset and Manual Reset OutputsFeaturesThe MAX6453–MAX6456 are low-power, dual-voltage ● Precision Factory-Set Reset Thresholds Fr ..
MAX6457UKD0B+T ,High-Voltage, Low-Current Voltage Monitors in SOT Packagesapplications. Each device is available in a smallPin Configurations appear at end of data sheet.SOT ..
MAX6457UKD3B+T ,High-Voltage, Low-Current Voltage Monitors in SOT Packagesapplications or allows(50µs, 150ms)the device to operate in transparent mode. The MAX6458 Internal ..
MAX6457UKD3C-T ,150 ms, high-voltage, low-current voltage monitor in SOT packageApplications+21V (NOMINAL)BATTERY IN DC-DC OUTUndervoltage Monitoring/ShutdownCHARGER CONVERTERSHDN ..
MAX6458UKD0A-T ,50 ms, high-voltage, low-current voltage monitor in SOT packageapplications or allows(50µs, 150ms)the device to operate in transparent mode. The MAX6458 Internal ..
MAX6458UKD0B+ ,High-Voltage, Low-Current Voltage Monitors in SOT PackagesELECTRICAL CHARACTERISTICS(V = 4V to 28V, T = -40°C to +125°C, unless otherwise specified. Typical ..
MAX3220BCAP-MAX3220BEAP
3V to 5.5V, up to 250kbps true RS-232 transceiver with 4microA autoshutdown plus and power-on reset. Reset threshold 4.25V.
_______________General DescriptionThe MAX3320 combines a microprocessor (µP) super-
visory circuit with an RS-232 transceiver. The power-on
reset performs a single function: it asserts a reset signal
whenever the VCCsupply voltage declines below a pre-
set threshold, staying asserted for at least 100ms after
VCCrises above the reset threshold. The MAX3320 has
an active-low RESEToutput, which is guaranteed to be in
the correct state for VCCdown to 1V. The reset compara-
tor is designed to ignore fast transients on VCC. Reset
thresholds suitable for operation with a variety of supply
voltages are available.
The MAX3320 transceivers have a proprietary low-
dropout transmitter output stage, enabling true RS-232
performance with a dual charge pump powered from a
+3V to +5.5V supply. The device requires only four
small 0.1µF external charge-pump capacitors, and is
guaranteed to run at data rates of up to 250kbps. It
comes in the space-saving 20-pin SSOP package.
________________________ApplicationsPalmtop Computers
Portable/Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
____________________________FeaturesPrecise Monitoring of 5V and 3.3V Power-
Supply Voltages:
— 100ms (min) Power-On RESETPulse Width
— Power-Supply Transient Immunity
— Guaranteed RESETValid to VCC= 1V4µA Supply Current Achieved with
AutoShutdown PlusReceivers Always ActivePower-On Reset Always Active4µA Low-Power Shutdown250kbps Guaranteed Data Rate
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
__________________Pin Configuration19-1253; Rev 0; 8/97
AutoShutdown Plus is a trademark of Maxim Integrated Products.
Typical Operating Circuit appears at end of data sheet.
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VCC= 3V to 5.5V, C1–C4 = 0.1µF (tested at 3.3V ±10%), C1 = 0.047µF, C2–C4 = 0.33µF (tested at 5V ±10%), 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.
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, FORCEOFF, FORCEON................................-0.3V to 6V
R_IN.................................................................................±25V
Output Voltages
T_OUT..........................................................................±13.2V
R_OUT, INVALID, RESET.......................-0.3V to (VCC+ 0.3V)
Short-Circuit Duration
T_OUT....................................................................Continuous
Continuous Power Dissipation (TA= +70°C)
SSOP (derate 8.00mW/°C above +70°C)....................640mW
Operating Temperature Ranges
MAX3320_CAP...................................................0°C to +70°C
MAX3320_EAP................................................-40°C to +85°C
Storage Temperature Range.............................-65°C to +160°C
Lead Temperature (soldering, 10sec).............................+300°C
Note 1:V+ and V- can have a magnitude of +7V (max), but their absolute difference cannot exceed +13V.
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
ELECTRICAL CHARACTERISTICS (continued)(VCC= 3V to 5.5V, C1–C4 = 0.1µF (tested at 3.3V ±10%), C1 = 0.047µF, C2–C4 = 0.33µF (tested at 5V ±10%), TA= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +25°C.)
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
TIMING CHARACTERISTICS(VCC= 3V to 5.5V, C1–C4 = 0.1µF, C1–C4 = 0.1µF (for 3.3V ±10%), C1 = 0.047µF, C2–C4 = 0.33µF (tested at 5V ±10%), = TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
__________________________________________Typical Operating Characteristics(VCC= 3.3V, 250kbps data rate, C1–C4 = 0.1µF, all transmitters loaded with 3kW. Typical values are at TA= +25°C, unless
otherwise noted.)
MAX3320A/B/L/T
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
______________________________________________________________Pin Description
____________________________Typical Operating Characteristics (continued)(VCC= 3.3V, 250kbps data rate, C1–C4 = 0.1µF, all transmitters loaded with 3kW. Typical values are at TA= +25°C, unless
otherwise noted.)
MAX3320A/B/L/T
______________ Detailed Description
Dual Charge-Pump Voltage ConverterThe MAX3320’s internal power supply consists of a reg-
ulated dual charge pump that provides output voltages
of +5.5V (doubling charge pump) and -5.5V (inverting
charge pump) while VCCremains in the 3V to 5.5V
range. The charge pumps operate in discontinuous
mode; they are enabled if the output voltages are less
than 5.5V, and disabled if output voltages exceed 5.5V.
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 5V EIA/TIA-232 levels. The
MAX3320 transmitters guarantee a 250kbps data rate
with worst-case loads of 3kWin parallel with 1000pF,
providing compatibility with PC-to-PC communication
software (such as LapLink™). Transmitters can be par-
alleled to drive multiple receivers. Figure 1 shows a
complete system connection.
When FORCEOFFis driven to ground, the transmitter’s
outputs become high impedance. When the
AutoShutdown Plus circuitry senses that all receiver
and transmitter inputs are inactive for more than 30sec,
the transmitters turn off and the outputs go into a high-
impedance state, but the receivers remain active.
When the power is off or the MAX3320 is shut down,
outputs may be driven up to ±12V.
The transmitter inputs do not have pull-up resistors.
Connect unused inputs to GNDor VCC.Laplink is a trademark of Traveling Software.
RS-232 ReceiversThe receivers convert RS-232 signals to CMOS-logic out-
put levels. All receivers have inverting outputs and are
active in shutdown FORCEOFF(Table 1).
AutoShutdown Plus ModeMaxim’s AutoShutdown Plus feature, which operates
when FORCEOFFis high and FORCEON is low, achieves
a 4µA supply current. When the MAX3320 senses no
valid signal levels on all receiver and transmitter inputs for
30sec, the on-board power supply and drivers shut off,
Table 1. MAX3320 Output Control Truth Table X = Don’t Care
*Time since last receiver or transmitter input activity
3V to 5.5V, up to 250kbps True RS-232 Transceiver
with 4µA AutoShutdown Plus and Power-On Reset
