MAX3218CAP+ Fast Delivery |IC PHOENIX CO.,LIMITED

MAX3218CAP+ ,1µA, 1.8V to 4.25V RS-232 Transceiver with AutoShutdown™FeaturesThe MAX3218 RS-232 transceiver is intended for bat - BETTER THAN BIPOLAR!tery-powered EIA/T ..
MAX3218EAP ,1A Supply Current / 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdownGeneral Description ________
MAX3218EAP ,1A Supply Current / 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdownFeaturesThe MAX3218 RS-232 transceiver is intended for bat- BETTER THAN BIPOLAR!tery-powered EIA/TI ..
MAX3218EPP ,1A Supply Current / 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdownMAX3218*19-0380; Rev 0; 3/951µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoS ..
MAX321CSA ,Precision, Dual-Supply, SPST Analog SwitchesELECTRICAL CHARACTERISTICS(V+ = +5V ±10%, V- = -5V ±10%, VINH = 3.5V, VINL = 2.5V, TA = TMIN to TMA ..
MAX321CSA+ ,Precision, Dual Supply, SPST, Analog CMOS SwitchesMAX320/MAX321/MAX32219-0350; Rev 0; 12/94Precision, Dual-Supply, SPST Analog Sw itches_____________ ..
MAX6445UK23L-T ,2.313 V, mP reset circuit with long manual reset setup periodFeaturesThe MAX6443–MAX6452 low-current microprocessor Single- or Dual-Supply Voltage Monitorsrese ..
MAX6454UT29S ,uP Supervisors with Separate VCC Reset and Manual Reset OutputsFeaturesThe MAX6453–MAX6456 are low-power, dual-voltage Precision Factory-Set Reset Thresholds Fro ..
MAX6454UT46S-T ,4.625 V, mP supervisor with separate Vcc reset and manual reset outputFeaturesThe MAX6453–MAX6456 are low-power, dual-voltage Precision Factory-Set Reset Thresholds Fro ..
MAX6455UT16S+T ,µP Supervisors with Separate VCC Reset and Manual Reset OutputsApplicationsRESET 1 6 MR RESET 1 6 MR● Set-Top Boxes ● Consumer ElectronicsMAX6453 MAX6455● DVD Pla ..
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 ..

MAX3218CAP+
1µA, 1.8V to 4.25V RS-232 Transceiver with AutoShutdown™
_______________General Description
The MAX3218 RS-232 transceiver is intended for bat-tery-powered EIA/TIA-232E and V.28/V.24 communica-tions interfaces that need two drivers and two receiverswith minimum power consumption from a single low-voltage supply. It provides a wide +1.8V to +4.25Voperating voltage range while maintaining true RS-232and EIA/TIA-562 voltage levels. The MAX3218 runsfrom two alkaline, NiCd, or NiMH cells without any formof voltage regulator. A guaranteed 120kbps data rateprovides compatibility with popular software for com-municating with personal computers.
Supply current is reduced to 1µA with Maxim’s newAutoShutdown™ feature. When the MAX3218 does notsense a valid signal level on the receiver inputs, the on-board power-supply and drivers shut down. Thisoccurs if the RS-232 cable is disconnected or if thetransmitters of the connected peripheral are turned off.The system turns on again when a valid level is appliedto either RS-232 receiver input. As a result, the systemsaves power without changes to the existing software.Additionally, the MAX3218 can be forced into or out ofshutdown, under logic control.
While shut down, all receivers can remain active or canbe disabled under logic control, permitting a systemincorporating the CMOS MAX3218 to monitor externaldevices while in low-power shutdown. Three-state dri-vers are provided on both receiver outputs so that multi-ple receivers, generally of different interface standards,can be on the same bus. The MAX3218 is available in20-pin DIP and SSOP packages.
________________________Applications
Battery-Powered Equipment
Subnotebook Computers
PDAs
Hand-Held Equipment
Peripherals
Cellular Phones
____________________________Feature
BETTER THAN BIPOLAR!1μA Supply Current Using AutoShutdown™Operates Directly from Two Alkaline,
NiCd or NiMH Cells+1.8V to +4.25V Single-Supply Voltage Range120kbps Data Rate GuaranteedLow-Cost Surface-Mount ComponentsMeets EIA/TIA-232E SpecificationsThree-State Receiver OutputsFlow-Through PinoutOn-Board DC-DC Converters20-Pin SSOP and DIP Packages
______________Ordering InformationContact factory for dice specifications.μA Supply Current, 1.8V to 4.25V-Powere
RS-232 Transceiver with AutoShutdown™
PART
MAX3218CPP
MAX3218CAP0°C to +70°C
0°C to +70°C
TEMP. RANGEPIN-PACKAGE
20 Plastic DIP
20 SSOP
19-0380; Rev 0; 3/95
MAX3218C/D
MAX3218EPP-40°C to +85°C
0°C to +70°CDice†
20 Plastic DIP™ AutoShutdown is a trademark of Maxim Integrated Products.
MAX3218EAP-40°C to +85°C20 SSOP
GND
C1+
GND
FORCEON
FORCEOFF
INVALID
TOP VIEW
C1-
T1OUT
T2OUTT2IN
T1IN
VCC
GND
R1IN
R2INR2OUT
R1OUT
DIP/SSOP
MAX3218
__________________Pin Configuration
μA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, VCC= 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA= TMINto TMAX, unless otherwise noted.Typical values are at VCC= 3.0V, TA= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functionaloperation 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.
Supply VoltagesVCC....................................................................-0.3V to +4.6V V+..........................................................(VCC- 0.3V) to +7.5VV-.......................................................................+0.3V to -7.4VVCCto V-..........................................................................+12VLX................................................................-0.3V to (1V + V+)Input VoltagesT_IN, FORCEON, FORCEOFF............................-0.3V to +7VR_IN.................................................................................±25VOutput VoltagesT_OUT.............................................................................±15V)R_OUT....................................................-0.3V to (VCC+ 0.3V)
Short-Circuit Duration, R_OUT, T_OUT to GND .......ContinuousContinuous Power Dissipation (TA= +70°C)Plastic DIP (derate 11.11mW/°C above +70°C)..........889mWSSOP (derate 8.00mW/°C above +70°C)..................640mWOperating Temperature RangesMAX3218C_ P...................................................0°C to +70°CMAX3218E_ P.................................................-40°C to +85°CStorage Temperature Range ...........................-65°C to +150°CLead Temperature (soldering, 10sec) ...........................+300°C
VCC= 3.0V, TA= +25°C, all R_IN open,FORCEON = GND, FORCEOFF = VCC
IOUT= -0.4mA, |R_IN|> 2.8V
IOUT= 1.0mA, -0.3V < R_IN < 0.3V
1µA supply current, Figure 4a
Figure 4a
R_OUT, IOUT= 1.0mA
T_IN, FORCEON = FORCEOFF= 0V or VCC
T_IN, FORCEON, FORCEOFF
FORCEOFF= GND, TA= +25°C, VCC= 3.0V
R_OUT, 0V ≤R_OUT ≤VCC,FORCEON = FORCEOFF= 0V
T_IN, FORCEON, FORCEOFF
R_OUT, IOUT= -0.4mA
CONDITIONS
VCC- 0.25
INVALIDOutput Low Voltage0.4-0.30.3Receiver Input ThresholdsTransmitters Disabled2.8Receiver Input Thresholds, Transmitters Enabled0.05±10Output Leakage CurrentVCC- 0.25VCC- 0.08Output Voltage High1.010Supply Current, AutoShutdown™1.84.25Operating Voltage Range0.4Output Voltage Low0.001±1Input Leakage Current0.67 x VCCInput Logic Threshold High
1.0100.33 x VCCInput Logic Threshold Low
UNITSMINTYPMAXPARAMETER
FORCEON = FORCEOFF= VCC= 3.0V, no loadmA2.03.0Supply Current,
AutoShutdown™ Disabled
Supply Current, ShutdownµA
INVALIDOutput High VoltageV
DC CHARACTERISTICS
AUTOSHUTDOWN (FORCEON = GND,FORCEOFF= VCC)
LOGIC INPUTS AND RECEIVER OUTPUTS
Positive threshold
Negative threshold-2.8
μA Supply Current, 1.8V to 4.25V-PowereRS-232 Transceiver with AutoShutdown™
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VCC= 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA= TMINto TMAX, unless otherwise noted.Typical values are at VCC= 3.0V, TA= +25°C.)500tDTTransmitter Output Disable Time
2500pF ||3kΩload each transmitter, one trans-
mitter switching, 150pF load each receiver= +25°C, VCC= 3.0V, RL= 3kΩto 7kΩ, CL= 50pF to 2500pF, measured from +3V to -3V or -3V to +3V
2500pF ||3kΩload
150pF load
150pF load
2500pF ||3kΩload
CONDITIONS200500tDRReceiver Output Disable Time90300tER
kbps120235Data Rate
Receiver Output Enable Time
V/µs3.030Transition Region Slew Rate
1.82.7tPLHTTransmitter Propagation Delay250450tETTransmitter Output Enable Time2901000tPHLR
2601000tPLHRReceiver Propagation Delay1.92.7tPHLT
UNITSMINTYPMAXSYMBOLPARAMETER
TIMING CHARACTERISTICS
(Circuit of Figure 1, VCC= 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA= TMINto TMAX, unless otherwise noted.Typical values are at VCC= 3.0V, TA= +25°C.)
VCC= 2.0V to 4.25V
CONDITIONS
UNITSMINTYPMAXPARAMETER
VCC= 1.8V to 4.25V
VCC= 1.8V to 4.25V0.3Input Threshold Low
-15V < R_IN < 15VkΩ357
VCC= 1.8V to 3.6V
Input Resistance
Input HysteresisV2.8Input Threshold High
VCC= 0V, -2V < T_OUT < 2V
Output Short-Circuit CurrentmA300Output Resistance
±24±100
All transmitter outputs loaded with 3kΩto groundOutput Voltage SwingV±5±6-25+25Input Voltage Range
EIA/TIA-232E RECEIVER INPUTS
EIA/TIA-232E TRANSMITTER OUTPUTS
Figure 4bµs250tWUReceiver Threshold toTransmitters Enabled
Figure 4bµs1tINVHReceiver Positive or NegativeThreshold to INVALIDHigh
Figure 4bµs30tINVLReceiver Positive or NegativeThreshold to INVALIDLow
AUTOSHUTDOWN TIMING
μA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™
TRANSMITTER OUTPUT VOLTAGE vs.
LOAD CAPACITANCE AT 120kbps
AX3218-04
LOAD CAPACITANCE (pF)
(V
VOUT+
VOUT-
SLEW RATE vs.
TRANSMITTER CAPACITANCE
MAX3218-05
LOAD CAPACITANCE (pF)
(V
+SLEW
-SLEW
DATA RATE 120kbps,
TRANSMITTERS LOADED WITH
3kW PLUS INDICATED CAPACITANCE
__________________________________________Typical Operating Characteristics
(Circuit of Figure 1, VCC= 1.8V, all transmitter outputs loaded with 3kΩ, TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT vs.
SUPPLY VOLTAGE
MAX3218-01
SUPPLY VOLTAGE (V)
(m
1 TRANSMITTER FULL DATA RATE
1 TRANSMITTER 1/8 DATA RATE
RL = 3kW + 2500pF
240kbps
120kbps
20kbps
0kbps
TRANSMITTING SUPPLY CURRENT
vs. LOAD CAPACITANCE
AX3218-02
LOAD CAPACITANCE (pF)
(m
20kbps
120kbps
VCC = 2.4V
TRANSMITTER 1 OPERATING
AT SPECIFIED BIT RATE,
TRANSMITTER 2 OPERATING
AT 1/16 THAT RATE.
235kbps
VOH
FORCEON, FORCEOFF
T_OUT
2V/div
VOL
TIME TO EXIT SHUTDOWN
(ONE TRANSMITTER HIGH,
ONE TRANSMITTER LOW)
100ms/div
VCC = 1.8V
RL = 3kW || 2500pF
_______________Detailed Description
The MAX3218 line driver/receiver is intended for bat-tery-powered EIA/TIA-232 and V.28/V.24 communica-tions interfaces that require two drivers and tworeceivers. The operating voltage extends from 1.8V to4.25V, yet the device maintains true RS-232 andEIA/TIA-562 transmitter output voltage levels. This widesupply voltage range permits direct operation from avariety of batteries without the need for a voltage regu-lator. For example, the MAX3218 can be run directlyfrom a single lithium cell or a pair of alkaline cells. Itcan also be run directly from two NiCd or NiMH cellsfrom full-charge voltage down to the normal 0.9V/cellend-of-life point. The 4.25V maximum supply voltageallows the two rechargeable cells to be trickle- or fast-charged while driving the MAX3218.
The circuit comprises three sections: power supply,transmitters, and receivers. The power-supply sectionconverts the supplied input voltage to 6.5V, providing thevoltages necessary for the drivers to meet true RS-232levels. External components are small and inexpensive.
The transmitters and receivers are guaranteed to oper-ate at 120kbps data rates, providing compatibility withLapLink™ and other high-speed communications soft-ware.
The MAX3218 is equipped with Maxim’s new propri-etary AutoShutdown™ circuitry. This achieves a 1µAsupply current by shutting down the device when theRS-232 cable is disconnected or when the connectedperipheral transmitters are turned off. While shut down,both receivers can remain active or can be disabledunder logic control. With this feature, the MAX3218 canbe in low-power shutdown mode and still monitor activi-ty on external devices. Three-state drivers are provid-ed on both receiver outputs.
Three-state drivers on both receiver outputs are provid-ed so that multiple receivers, generally of different inter-face standards, can be wire-ORed at the UART.itch-Mode Power SupplyThe switch-mode power supply uses a single inductorwith one diode and three small capacitors to generate±6.5V from an input voltage in the 1.8V to 4.25V range.
Inductor SelectionUse a 15µH inductor with a saturation current rating of atleast 350mA and less than 1Ωresistance. Table 1 listssuppliers of inductors that meet the 15µH/350mA/1Ωspecifications.μA Supply Current, 1.8V to 4.25V-Powere
RS-232 Transceiver with AutoShutdown™
Receiver InputsR2IN, R1IN11, 12
Transmitter Outputs, swing between V+ and V-T2OUT, T1OUT13, 14
Negative Supply generated on-boardV-15
Terminal for Charge-Pump CapacitorC1-, C1+16, 18
Positive Supply generated on-boardV+19
GroundGND5, 17, 20
Supply Voltage Input, 1.8V to 4.25V. Bypass to GND with at least 1µF.VCC6
Transmitter InputsT1IN, T2IN7, 8
Receiver OutputsR1OUT, R2OUT9, 10
Drive low to shut down transmitters and on-board power supply, overriding all automatic circuitry and FORCEON.FORCEOFF4
Drive high when FORCEOFF= high to override automatic circuitry, keeping transmitters on.FORCEON3
PIN
Output of Invalid Signal Detector. Low if invalid RS-232 levels are present on all receiver inputs,otherwise high.INVALID2
Inductor/Diode Connection PointLX1
FUNCTIONNAME
______________________________________________________________Pin Description
™ LapLink is a trademark of Traveling Software, Inc.
AutoShutdown is a trademark of Maxim Integrated Products.
Diode SelectionKey diode specifications are fast recovery time (<10ns),average current rating (>100mA), and peak current rat-ing (>350mA). Inexpensive fast silicon diodes, such asthe 1N6050, are generally recommended. More expen-sive Schottky diodes improve efficiency and give slightlybetter performance at very low VCCvoltages. Table 1lists suppliers of both surface-mount and through-holediodes. 1N914s are usually satisfactory, but specifica-tions and performance vary widely with different manu-facturers.
Capacitor SelectionUse capacitors with values at least as indicated inFigure 1. Capacitor C2 determines the ripple on V+, butnot the absolute voltage. Capacitors C1 and C3 deter-mine both the ripple and the absolute voltage of V-.Bypass VCCto GND with at least 1µF (C4) placed closeto pins 5 and 6. If the VCCline is not bypassed else-where (e.g., at the power supply), increase C4 to 4.7µF.
You may use ceramic or polarized capacitors in alllocations. If you use polarized capacitors, tantalumtypes are preferred because of the high operating fre-quency of the power supplies (about 250kHz). If alu-minum electrolytics are used, higher capacitancevalues may be required.μA Supply Current, 1.8V to 4.25V-Powered
RS-232 Transceiver with AutoShutdown™
MANUFACTURERPHONEPART NUMBERFAX
USA (814) 237-1431LQH4N150K-TAMurata-ErieUSA (814) 238-0490
USA (708) 956-0666Japan (03) 3607-5111CD43150SumidaUSA (708) 956-0702Japan (03) 3607-5428
USA (508) 853-5000TMPD6050LTAllegroUSA (508) 853-7556
USA (708) 803-6100Japan (03) 3278-5111NLC453232T-150KTDKUSA (708) 803-6296Japan (03) 3278-5358
USA (516) 435-1110CMPSH-3 (Schottky)Central SemiconductorUSA (516) 435-1824
USA (408) 749-0510MMBD6050LT1 (silicon)MotorolaUSA (408) 991-7420
USA (401) 762-3800PMBD6050 (silicon)PhilipsUSA (401) 767-4493
USA (408) 749-05101N6050 (silicon),1N5817 (Schottky)MotorolaUSA (408) 991-7420
Table 1. Suggested Component Suppliers
GND
T2OUT
R1IN
R2IN
T1OUT
C1-
C1+
T2IN
R1OUT
R2OUT
T1IN14
C3F
C1
0.47mF
C4F
C2F
5, 17, 20
VCC119
1.8V to
4.25V
15mH1N6050
FORCEON
INVALID
FORCEOFF
MAX3218
Figure 1. Typical Operating Circuit
Inductors
Diodes—Surface-Mount
Diodes—Through-Hole

Partno	Mfg	Dc	Qty	Available	Descript
MAX3218CAP+	MAXIM	N/a	34	avai	1µA, 1.8V to 4.25V RS-232 Transceiver with AutoShutdown™
MAX3218CAP+ \|MAX3218CAP	MAX	N/a	11	avai	1µA, 1.8V to 4.25V RS-232 Transceiver with AutoShutdown™