ANALOG W DEVICES CMOS RS-232 Drivers/Receivers

D~5C-c::t\ +~VI u ~ -,. ANALOGW DEVICES

+5VPoweredCMOSRS-232Drivers/Receivers

FEATURESSingle 5 V Power SupplyMeets All RS-232-C and V.28 SpecificationsMultiple Drivers and ReceiversOn-Board DC-DC Converters:t:9 V Output Swing with +5 V Supplylow Power CMOS: 5 mA Operationlow Power Shutdown $1 p.A3-State TTl/CMOS Receiver Outputs:t:30 V Receiver Input levelsPlug-In Replacement for MAX230-241

APPLICATIONSComputersPeripheralsModemsPrintersInstruments

GENERAL DESCRIPTIONThe AD230 family of 5 V only, RS-232 line drivers/receiversprovides a variety of configurations to fit most communicationneeds, especially in applications where :t 12 V is not available.The AD230, AD235, AD236 and AD241 feature a low powershutdown mode which reduces power dissipation to less than5 j.LW making them ideally suited for battery powered equip-ment. The AD233 and AD235 do not require any external com-ponents and are particularly useful in applications where printedcircuit board space is critical.

1\ll members of the AD230 family, except the AD231 and theAD239, include tWointernal charge pump voltage converterswhich allow operation from a single +5 V supply. These con-verters convert the + 5 V input power to the :t 10 V required forRS-232 output levels. The AD231 and AD239 are designed tooperate from +5 V and + 12 V supplies. An internal + 12 V to- 12 V charge pump voltage converter generates the - 12 Vsupply.

In order to minimize the package count in all applications, awide selection of driver/receiver combinations is available (seetable below).

SELECTION TABLE

Information furnished by Analog Devices is believed to be accurate andreliable. However, no responsibility is assumed by Analog Devices for itsuse; nor for any infringements of patents or other rights of third partieswhich may result from its use. No license is granted by implication orotherwise under any patent or patent rights of Analog Devices.

"

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.Tel: 617/329-4700 Fax: 617/326-8703 Twx: 710/394-6577Telex: 924491 Cable: ANALOG NORWOODMASS

No. of No. of Low Power TTLPart Power RS-232 RS-232 External Shutdown Three-State No. ofNumber Supply Voltage Drivers Receivers Capacitors (SD) EN Pins

AD230 +5 V 5 0 4 Yes No 20AD231 +5 V & +7.5 V 2 2 2 No No 14

to 13.2VAD232 +5 V 2 2 4 No No 16AD233 +5 V 2 2 None No No 20AD234 +5 V 4 0 4 No No 16AD235 +5 V 5 5 None Yes Yes 24AD236 +5 V 4 3 4 Yes Yes 24AD237 +5 V 5 3 4 No No 24AD238 +5 V 4 4 4 No No 24AD239 +5 V & +12 V 3 5 2 No Yes 24AD241 +5 V 4 5 4 Yes Yes 28

OBSOLETE

SPECIFICATIONS(Vee = +5 V:t 10% (AD231,AD232,AD234,AD236,AD238,AD239,AD241);Vee= +5 V :t 5% (AD233,AD235);V+ = 7.5Vto 13.2V (AD231)&V+ = 12 V :t 10% (AD239);All Specifications Tminto Tmaxunlessotherwisenoted.)

NOTE'Sample tested to ensure compliance.

Specifications subject to change without notice.

ABSOLUTE MAXIMUM RATINGS*(T A = 25°C unless otherwise noted)

Vcc 0.3Vto+6V

V+ (Vcc-0.3V)to+13VV- +0.3Vto-13VInput Voltages

TIN 0.3Vto(Vcc+0.3V)R1N ::I::30V

Output Voltages

TOUT' . . . . . . . . . . . . . . (V+, +0.3 V) to (V-, -0.3 V)ROUT O.3Vto(Vcc+O.3V)

Short Circuit Duration

TOUT Continuous

Power DissipationCerdip (Derate 9.5 mW/OCabove +70°C) 675 mWPlastic DIP (Derate 7 mW/OCabove +70°C) 375 mWSOIC (Derate 7 mW/oC above +70°C) 375 mW

Operating Temperature RangeCommercial (J Version) 0 to +70°CIndustrial (A Version) . . . . . . . . . . . . . . . -40°C to +85°CExtended (S Version) """"""" -55°C to + 125ac

Storage Temperature Range. . . . . . . . . . . -65ac to + 150acLead Temperature (Soldering, 10 secs) . . . . . . . . . . . + 300°C

*This is a stress rating only and functional operation of the deviceat these or any other conditions above those indicated in theoperation sections of this specification is not implied. Exposureto absolute maximum rating conditions for extended periods oftime may affect reliability.

CAUTION

ESD (electrostatic discharge) sensitive device. The digital control inputs are diode protected;however, permanent damage may occur on unconnected devices subject to high energy electro-static fields. Unused devices must be stored in conductive foam or shunts. The protective foamshould be discharged to the destination socket before devices are removed.

-2-

~--- -

Parameter Min Typ Max Units Test Conditions/Comments

Output Voltage Swing ::I::5 ::I::9 Volts All Transmitter Outputs Loaded with 3 kil to GroundVcc Power Supply Current 4 10 mA No Load, T A = 25°C

0.4 1 mA AD231, AD239V+ Power Supply Current 5 10 mA No Load, V+ = 12 V AD231 & AD239 OnlyShutdown Supply Current 1 10 f.LA TA = +25°CInput Logic Threshold Low, VINL 0.8 V TIN' EN, SDInput Logic Threshold High, VINH 2.0 V TIN' EN, SDLogic Pullup Current 15 200 f.LA TIN = 0 VRS-232 Input Voltage Range -30 +30 VRS-232 Input Threshold Low 0.8 1.2 V Vcc = 5 V, TA = +25°CRS-232 Input Threshold High 1.7 2.4 V Vcc = 5 V, TA = +25°CRS-232 Input Hysteresis 0.2 0.5 1.0 V Vcc=5VRS-232 Input Resistance 3 5 7 kil Vcc = 5V, TA = +25°CTTL/CMOS Output Voltage Low, VOL 0.4 V lOUT = 3.2 mATTL/CMOS Output Voltage High, VOH 3.5 V lOUT = -1.0 mATTL/CMOS Output Leakage Current 0.05 ::1::10 f.LA EN = Vceo0 V ::; ROUT::;VccOutput Enable Time (TEN) 400 ns AD235, AD236, AD239, AD241

(Figure 25. RL = 1 kil, CL = 150 pF)Output Disable Time (Tod 250 ns AD235, AD236, AD239, AD241

(Figure 25. RL = 1 kil, CL = 150 pF)Propagation Delay 0.5 f.Ls RS-232 to TTLInstantaneous Slew Ratel 30 V/f.LS CL = 10pF, RL = 3-7kil, TA = +25°CTransition Region Slew Rate 3 V/f.LS RL = 3 kil, CL = 2500pF

Measured from +3 V to -3 V or -3 V to +3 VOutput Resistance 300 il Vcc = V+ = V- = 0 V, VOUT= ::1::2VRS-232 Output Short Circuit Current ::1::10 mA

OBSOLETE

)

)

)

)

)

T30UT

T10UT

T20UT

T21N

T1IN AD230TOP VIEW

(Not to Scale)GND

Vcc

C1+

V+

NC =NO CONNECT

Figure 1. AD230 DIP/SOIC Pin ConfigurationGND-

6-"INTERNAL 400kfl PULL.UP RESISTORON EACH TTLiCMOS INPUT

Figure 2. AD230 Typical Operating Circuit

DIP

AD231TOP VIEW

(Not to Scale)T10UT

A1oUT

T21N T11N

SOIC

.C+C-V-

T20UT

A21N

AD231TOP VIEW

(Not to Scale) II!!!A11N

A2oUT

T21N

NC

NC =NO CONNECT

Figure 3. AD231 DIP & SOIC Pin Configurations

{

T11NTTLICMOSINPUTS*

T21N

{

R10UT

TTL/CMOSOUTPUTS

R2oUT

AD231GND-

12-"INTERNAL 400kfl PULL.UP RESISTORON EACH TTL/CMOS INPUT

**INTERNAL 5kfl PULL.DOWN RESISTORON EACH RS.232 INPUT


-3-

10l-lF

I+ 16V

T1INT 12 . T1oUT

T21N4 3

T2oUT

TTL/CMOS i T31N14 1 2"

INPUTS* T30UT OUTPUTS

15 20T41N T4oUT

T5'N19 16

T50UT,

NC18

AD23017

SD

1N914 OR EQUIVALENTVcc I..T

C+ V++12V TO -12V

VOLTAGECONVERTERv-h4.71-lF

C- I+16V

81 1_'-...- 111

. T1. }

RS-232OUTPUTS

71 I_- 14 . T2oUT

91 _"""':-1 110

RI'"}

.RS-232

_./ I 15INPUTS**

61R21N

OBSOLETE

AD232TOP VIEW

(Not to Scale)

Figure 5. AD232 DIP/SOIC Pin Configuration

+5VINPUT

10".F...L+6.3VI

161 '(;1+ Vcc

+5V TO +10V 23Ic1-VOLTAGE DOUBLERV+

641C2+ +10V TO -10V V-

C2-VOLTAGEINVERTER5

10".F

~+16:0"'

}RS-232OUTPUTS

T2oUT

R1'N

}RS-232INPUTS"

R2'N

-'INTERNAL 400kil PULL-UP RESISTORON EACH TTLiCMOS INPUT

**INTERNAL 5kil PULL-DOWN RESISTORON EACH RS-232 INPUT

+5VINPUT

7

Vcc

{n'N

TTL/CMOSINPUTS'

T2'N

C2+

~

11

C2+ 15

C2- 10

AD232GND-

15


T21N

T11N

R1oUT

R11N

T1oUT AD233TOPVIEW

(Not to Scale)GND

VCC

C1+

GND

Figure 7. AD233 DIP Pin Configuration

2

{R10UT

TTL/CMOSOUTPUTS

R2oUT -

DO NOT MAKE

{CONNECTIONS TOTHESE PINS

INTERNAL

{-10V POWERSUPPLY

INTERNAL+10V POWERSUPPLY

3

20

8C1+

~C1-

121V- AD23317

V-C2- .16

14. V+2,ND

6~

9

-'INTERNAL 4O0kil PULL-UP RESISTORON EACH TTLiCMOS INPUT

"INTERNAL 5kil PULL-DOWN RESISTORON EACH RS-232 INPUT


-4-~- ---

5T1oUT

}

RS-232OUTPUTS

T2oUT

R1'N

}RS-232INPUTS"

R2'N

18

4

19

{ T1,"1

1_"'- 114

TTL/CMOSINPUTS'

T2'N11_"'- 17

{ RI, I

_/.I 113

TTL/CMOSOUTPUTS

R2oUT- 91 __I 18OBSOLETE

J+5VINPUT

Vcc

7. VC1+ cc+5V TO +10V 8

9Ic1-VOLTAGE DOUBLERV+12

101C2+ +10V TO -10V V-C2-VOLTAGE INVERTER

6

10l1F

~+16V

T10UT

T2oUT

V+ C1-

T21N

T11NAD234

TOP VIEW(Not to Scale)GND

C1+

)Figure 9. AD234 DIP/SOIC Pin Configuration AD234

GND~-

'INTERNAL 400kfi PULL-UP RESISTORON EACH TTL/CMOS INPUT


) +5VINPUT

12

v:T1'N 8 3 T10UT

T20N 7 4 T2oUT

TIL/CMOS ~ 15 2 I RS-232

INPUTS' I T3'N T30UT r OUTPUTS

T~: :~ ~T~15'N 15 15ouTAD235

R1ouT 9 10 R1'N

R2oUT 6 5 R2'N

TIL/CMOS I 23 24 ~RS-232

OUTPUTS 1 R3oUT R3'N I INPUTS"

R4oUT 17 18 R4.N

14 13R5oUT R5'N

- ~ ~EN SD

GND

~11'INTERNAL4OOkU PUll-UP RESISTOR ON EACH TTlfCMOS INPUT

"INTERNAl SkU PUll-DOWN RESISTOR ON EACH RS-232 INPUT


-5-

Figure 11. AD235 DIP Pin Configuration

)

T1'N4

T10UT

T2'N3 2

T20UT

TTL/CMOS i RS-232INPUTS* OUTPUTS

T3'N13 16

T30UT

T4'N . 141 I P5 .T40UT

T4oUT

T30UT

T10UT

\ ) T2OUT

R21N

R2 AD235TOP VIEW

T21N 7 (Not to Scale)

T1IN

R1oUT

OBSOLETE


10".F10 ~ T-

6.3VC1+ Vcc +

121C1- vo~i:G~OD~0°~lER V+ 11

131C2+ +10VTO-10V V- 15C2- VOLTAGE INVERTER

14 -

T30UT

T1oUT

T2oUT

R11N

R1oUT

T21N AD237TOP VIEW

(Not to Scale)T11N

GND

Vcc


GND-8

-='INTERNAl400kU PUll-UP RESISTOR ON EACH TTl/CMOS INPU-;

ulNTERNAl 5kU PUll-DOWN RESISTOR ON EACH RS-232 INPUT

10".F

J::+16V

2

3

-6-


10".F

*+16V

T1'N2

T10UT

T2'N6 3

T2ouT

TTL/CMOS 1RS-232

INPUTS' OUTPUTS18 1

TJON T30uT

AD23619 24

T4'N T4 T4oUT

5 4R1oUT R1 R1'N

TTL/CMOS122 23

I RS-232

OUTPUTS R2oUT R2'N INPUTS'

R30UT17 16

R30N

EN20 21

SDGND

-4-8

'INTERNAL400kH PUll.UP RESISTORON EACHTTl/CMOS INPUTuiNTERNAl5kH PUll.DOWN RESISTORON EACHRS.232 INPUT


T30UT 11 I .

T10UT

T2oUT

R1'N

R1oUT

T2"; AD235TOP VIEW

T11N 7 (Notto Scale)GND

Vcc

7T1'N-

6T2'N-

TTLICMOSi18

TJON-INPUTS'

19T4'N-

21T5'N-

R1oUT..--2.

22

TTLICMOS iR2oUT-

OUTPUTS

17R30UT

AD23724

20

4

23

16

T10UT

"-. "'.,'T30UT OUTPUTS

T4ouT

T50UT

:

R1'N

"mR2oN INPUTS"

R:lIN

OBSOLETE

AD238TOP VIEW

(Not to Scale)

10f.'F

*+16V

}

R11N

2T10UT

T2oUT

nOUT

R2'N

R2oUT

n'N

R1oUT24

AD23820

GND

Vcc

) 23

16

Figure 17, AD238 DIP/SOIC Pin ConfigurationGND---e=

'INTERNAL 400k1l PUll.UP RESISTOR ON EACH TTliCMOS INPUT"INTERNAl 5k1l PUll-DOWN RESISTOR ON EACH RS.232 INPUT

) Figure 18. AD238 Typical Operating Circuit

NC= NO CONNECT

) Figure 19. AD239 DIP/SOIC Pin Configuration

GND~=

'INTERNAL 400k1l PUll.UP RESISTOR ON EACH Tn/CMOS INPUT"INTERNAl 5kll PUll.DOWN RESISTOR ON EACH RS.232 INPUT

Figure 20, AD239 Typical Operating Circuit

-7-

T20UTRS-232OUTPUTS

IT30UT

T4ouT

R1'N

R2'N,

RS-232INPUTS"

,R3'N

R4'N

+12V:10%

1N914OREQUIVALENT

10f.'F

{'

n'N n nOUT

TTL/CMOS 23 20 RS-232INPUTS. T2'NT20UT OUTPUT!>

--;--4TJ'N T3 T30UTAD239

R1oUT. "I O<.R1R1'N

22 21R2oUT R2'N

TTLiCMOS J 17 18

IRS-232

OUTPUTS R30UT R3'N INPUTS"

R4oUT11 12

R4'N

R50u,10 9

R5'N

EN14 15

NC

R1oUT

)R1'N

GND

VCC

V+

C+ AD239TOP VIEW

(Not to Scale)V-

R5'N

OBSOLETE

12 .C1+ Vcc

I +5V TO +10V 1314 C1- VOLTAGE DOUBLERV+

17151C2+ +10V TO -10V V- 10",F

VOLTAGE INVERTERI

16VC2- +

16 -= ,n'N 7 2 nOUT

T2'N 6 3 T2oUT~~~ I~INPUTS' I r OUTPUTS

T3'N 20 1 T30uT

~~T4'N~- ITy I - T4oUT

AD2418 9

R1oUT R1'N

R2oUT 5 4 R2'N

TTL/CMOS -1 26 27 L RS-232

OUTPUTS I R30UT R3'N r INPUTS"

R4oUT 22 23 R4'N

R50UT 19 18 R5'N

- 24 25EN SD

GND

-4:- 10'INTERNAL400kU PUll-UP RESISTORON EACHTTl/CMOSINPUT

ulNTERNAl SkU PUll-DOWN RESISTORON EACHRS-232INPUT


Figure 21. AD241 SOIC Pin Configuration

-8-

T30UT I1 I.

nOUT

T2OUT

R21N

R2oUT

T21NAD241

T11N 7 TOP VIEW

R1oUT B (NottoScale)

R11NOBSOLETE

')

PIN FUNCTIONDESCRIPTION

Mnemonic Function

Vcc Power Supply Input 5 V :!: 10% (AD231, AD232, AD234, AD236, AD238, AD239, AD241).5 V:!: 5% (AD233, AD235).

Internally generated positive supply (+ 10 V nominal) on all parts except AD231 and AD239.AD231 requires external 7.5 V to 13.2 V supply; AD239 requires external 10.8 V to 13.2 V supply.

V+

V-

GND

Internally generated negative supply (-10 V nominal).

Ground pin. Must be connected to 0 V.

C+

C-

(AD231 and AD239 only). External capacitor (+ terminal) is connected to this pin.

(AD231 and AD239 only). External capacitor (- terminal) is connected to this pin.

C1+ (AD230, AD232, AD234, AD236, AD237, AD238, AD241) External capacitor (+ terminal) isconnected to this pin.(AD233) The capacitor is connected internally and no external connection to this pin is required.

(AD230, AD232, AD234, AD236, AD237, AD238, AD241) External capacitor (- terminal) isconnected to this pin.(AD233) The capacitor is connected internally and no external connection to this pin is required.

)Cl-

C2+ (AD230, AD232, AD234, AD236, AD237, AD238, AD241) External capacitor (+ terminal) isconnected to this pin.(AD233) The capacitor is connected internally and no external connection to this pin is required.

(AD230, AD232, AD234, AD236, AD237, AD238, AD241) External capacitor (- terminal) isconnected to this pin.(AD233) The capacitor is connected internally and no external connection to this pin is required.

Transmitter (Driver) Inputs. These inputs accept TTL/CMOS levels. An internal 400 kG pull-upresistor to Vcc is connected on each input.

Transmitter (Driver) Outputs. These are RS-232 levels (typically:!: 10 V).

Receiver Inputs. These inputs accept RS-232 signal levels. An internal 5 kG pull-down resistor toGND is connected on each input.

Receiver outputs. These are TTL/CMOS levels.

Enable Input (AD235, AD236, AD239, AD241). This is an active low input which is used toenable the receiver outputs. With EN = 0 V, the receiver outputs are enabled. With EN = 5 V,the outputs are placed in a high impedance state. This facility is useful for connecting tomicroprocessor systems.

NC

Shutdown input. (AD230, AD235, AD236, AD241). With SD = 5 V, the charge pump is disabled,the receiver outputs are placed in a high impedance state and the driver outputs are turned off. Thesupply current reduces to <5 f.LAmaking these parts ideally suited for battery operation.

No Connect. No connections are required to this pin.

)

-9-~~- ~-

C2-

) TIN

TOUT

R1N

ROUT

EN

)SD

OBSOLETE

GENERAL INFORMATIONThe AD230-AD241 family of RS-232 drivers/receivers are de-signed to solve interface problems by meeting the RS-232-Cspecifications while using a single digital + 5 V supply. The RS-232-C standard requires transmitters which will deliver ::t5 Vminimum on the transmission channel and receivers which canaccept signal levels down to ::t3 V. The AD230-AD241 meetthese requirements by integrating step up voltage converters andlevel shifting transmitters and receivers onto the same chip.CMOS technology is used to keep the power dissipation to anabsolute minimum. A comprehensive range of transmitter/receiver combinations is available to cover most communicationsneeds.

The AD230, AD235, AD236 and AD241 are particularly usefulin battery powered systems as they feature a low power shut-down mode which reduces power dissipation to less than 5 f.-lW.

The AD233 and AD235 are designed for applications wherespace saving is important as the charge pump capacitors aremolded into the package.

The AD231 and AD239 include only a negative charge pumpconverter and are intended for applications where a positive12 V is available.

To facilitate sharing a common line or for connection to a mi-croprocessor data bus the AD235, AD236, AD239 and AD241feature an enable (EN) function. When disabled, the receiveroutputs are placed in a high impedance state.

CIRCUIT DESCRIPTIONThe internal circuitry in the AD230-AD241 consists of threemain sections. These are:

(a) A charge pump voltage converter(b) RS-232 to TTL/CMOS receivers(c) TTL/CMOS to RS-232 transmitters

Charge Pump DC-DC Voltage ConverterThe charge pump voltage converter consists of an oscillator anda switching matrix. The converter generates a ::t10 V supplyfrom the input 5 V level. This is done in two stages using aswitched capacitor technique as illustrated in Figures 23 and 24.First, the 5 V input supply is doubled to 10 V using capacitorCl as the charge storage element. The 10 V level is then in-verted to generate -10 V using C2 as the storage element.

51/ ~ 3

vcc o cr;C '~ V+=2Vcc. + ' +'C1 ' C3

52 ~ - T 54';' T--GNDo cr:o 4 <::~ Vcc, ,, ,

~~

Figure 23. Charge-Pump Voltage Doubler

~--

51/ ~ 3V+ o <Ji(. .0-+-0 GND

FROM : + :.J.: ~.VOLTAGE DOUBLER S2./ C2 T S4';' T C4

GND 0--<:5:~:~ V-=-(V+). ,. ,~,~

INTERNAL

OSCILLATOR

Figure 24. Charge-Pump Voltage Inverter

Capacitors C3 and C4 are used to reduce the output ripple.Their values are not critical and can be reduced if higher levelsof ripple are acceptable. The charge pump capacitors Cl and C2may also be reduced at the expense of higher output impedanceon the V+ and V-supplies.

The V+ and V- supplies may also be used to power externalcircuitry if the current requirements are small.

Transmitter (Driver) SectionThe drivers convert TTL/CMOS input levels into RS-232-C out-put levels. With Vcc = +5 V and driving a typical RS-232-Cload, the output voltage swing is ::t9 V. Even under worst caseconditions the drivers are guaranteed to meet the ::t5 V RS-232-Cminimum requirement.

The input threshold levels are both TTL and CMOS compatiblewith the switching threshold set at Vcc/4. With a nominalVcc = 5 V the switching threshold is 1.25 V typical. Unusedinputs may be left unconnected, as an internal 400 kil pull-upresistor pulls them high forcing the outputs into a low state.

As required by the RS-232-C standard, the slew rate is limitedto less than 30 V/f.-lSwithout the need for an external slew limit-ing capacitor and the output impedance in the power-off state isgreater than 300 il.

Receiver Section

The receivers are inverting level shifters which accept RS-232-Cinput levels (::t5 V to ::tIS V) and translate them into 5 V TTL/CMOS levels. The inputs have internal 5 kil pull-down resistorsto ground and are also protected against overvoltages of up to::t30 V. The guaranteed switching thresholds are 0.8 V minimumand 2.4 V maximum which are well within the ::t3 V RS-232requirement. The low level threshold is deliberately positive asit ensures that an unconnected input will be interpreted as a lowlevel.

The receivers have Schmitt trigger inputs with a hysteresis levelof 0.5 V. This ensures error-free reception for both noisy inputsand for inputs with slow transition times.

Shutdown (SO)The AD230, AD235, AD236 and AD241 feature a control inputwhich may be used to disable the part and reduce the powerconsumption to less than 5 f.-lW. This is very useful in batteryoperated systems. With SD = 5 V, the charge pump is disabled,the receiver outputs are placed in a high impedance state andthe driver outputs are turned off.

-10-

---

OBSOLETE

, Enable InputThe AD235, AD236, AD239 and AD241 feature an enable in-put (EN). It is used to enable the receiver outputs. WithEN = 0 V the outputs are enabled. With EN = 5 V the outputsare placed in a high impedance state. This function allows theoutputs to be connected directly to a microprocessor data bus. Itcan also be used to allow receivers from different devices toshare a common data line. The timing diagram for the enablefunction is shown in Figure 25.

Figure 25. Enable Timing

) APPLICATION HINTS

Protection for Shorts to z15 V SuppliesThe driver outputs are internally protected against shorting toground, to other driver outputs, to V+ or to V-. In practice,these are the highest voltages likely to be encountered in an ap-plication. lithe possibility exists for shorting to :t 15 V, then itis recommended that external protection be provided. This maybe done by connecting a series 220 !1 resistor on each transmit-ter output.

)

AD230-AD241

Figure 26. Protection for Shorts to :!::15 V

)

Over.Voltag~ Protection for AD231, AD239The AD231 and AD239 require an external + 12 V supply asthey do not contain an internal V+ generator. It is importantthat this supply be switched on before the 5 V, Vcc supply.

If there is a possibility that the Vcc supply will be switched onfirst, or if the 12 V supply may be inadvertently shorted toground, then it is recommended that a diode (IN914 or equiva-lent) be connected in series with the 12 V input. This will notaffect normal operation but it ensures that under fault condi-tions, the device will be protected.

Figure 27. Diode Protection Scheme for AD231 and AD239

High Baud Rate OperationThe RS-232-C standard requires that "For Data and TiminginterchangeCircuits, the timefor the signal to pass through the tran-sition regionshall not exceed one millisecondorfour percent of thenominal duration of the signal elementon that interchangecircuit,whichever is the lesser." With the maximum transmission rate of19.2 kbaud, this translates into a minimum slew rate of 3 V/J.Ls.The typical slew rate of the AD230-AD241 is 3 V/J.Lsundermaximum loading conditions and therefore meets the standard.

The V.28 standard is more stringent and requires a transitiontime which will not exceed three percent of the nominal signalduration. This translates into a slew rate of 4 V/J.Lsat the maxi-mum 19.2 kbaud rate. In practice, less than ideal slew rates willhave negligible affect on the data transmission. The result is thatthe valid mark/space duration is slightly shorter than the opti-mum because the signal spends more time in the transition re-gion. The valid duration remains more than adequate for error-free reception even at maximum transmission rates and underworst case load conditions.

Driving Long CablesIn accordance with the RS-232-C standard, long cables are per-missible provided that the total load capacitance does not exceed2500 pF. For longer cables which do exceed this, then it is pos-sible to trade off baud rate vs. cable length. Large load capaci-tances cause a reduction in slew rate, and hence the maximumtransmission baud rate is decreased. The AD23D-AD241 aredesigned so that the slew rate reduction with increasing loadcapacitance is minimized.

For the receivers, it is important that a high level of noise im-munity be inbuilt so that slow rise and fall times do not causemultiple output transitions as the signal passes slowly throughthe transition region. The AD230-AD241 have 0.5 V of hystere-sis to guard against this. This ensures that, even in noisy envi-ronments, error-free reception can be achieved.

-11-~ --

3V

\EN

IovI I

I I

I I

TENI

T DlSII

.......- -... ..-)

I I

t3.SV

' VOH- O.1V

ROUT DATA VALID

O.8V +- VOL+O.1V

+SV +12V

Lf:.

Vcc V+

AD231 & AD239

{/OBSOLETE

ORDERINGINFORMATION

*= 0.6" DIP package (all other DIP packages = 0.3")

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~--

Temperature Temperature TemperaturePart Range Package Part Range Package Part Range Package

AD230 AD23! AD232

AD230JN 0 to +70'C 20-Lead AD23IJN 0 to + 70'C 14-Lead AD232JN 0 to +70'C 16-LeadPlastic DIP Plastic DIP Plastic DIP

AD230JR 0 to + 70'C 20-Lead AD23IJR 0 to +70'C 16-Lead AD232JR 0 to +70'C 16-LeadSOIC SOIC SOIC

AD230AN -40'C to +85'C 20-Lead AD23IAN -40'C to +85'C 14-Lead AD232AN -40'C to +85'C 16-LeadPlastic DIP Plastic DIP Plastic DIP

AD230AR -40'C to +85'C 20-Lead AD23lAR -40'C to +85'C 16-Lead AD232AR -40'C to +85'C l6-LeadSOIC SOIC SOIC

AD230AQ -40'C to +85'C 20-Lead AD23lAQ -40'C to +85'C 14-Lead AD232AQ -40'C to +85'C 16-LeadCerdip Cerdip Cerdip

AD23ISQ -55'C to + l25'C 14-Lead AD232SQ -55'C to + l25'C l6-Lead

Cerdip Cerdip

AD233 AD234 AD235

AD233JN 0 to + 70'C 20-Lead AD234JN 0 to + 70'C l6-Lead AD235JN 0 to + 70'C 24-LeadPlastic DIP Plastic DIP Plastic DIP*

AD233AN -40'C to +85'C 20-Lead AD234JR 0 to + 70'C 16-Lead AD235AN -40°C to +85°C 24-LeadPlastic DIP SOIC Plastic DIP*

AD234AN -40°C to +85°C 16-Lead AD235AQ -40°C to +85°C 24-LeadPlastic DIP Ceramic*

AD234AR -40'C to +85°C 16-LeadSOIC

AD234AQ -40'C to +85°C 16-Lead

Cerdip

AD234SQ -55°C to + 125°C l6-Lead

Cerdip

AD236 AD237 AD238

AD236JN 0 to +70°C 24-Lead AD237JN 0 to + 70'C 24-Lead AD238JN 0 to + 70'C 24-LeadPlastic DIP Plastic DIP Plastic DIP

AD236JR 0 to + 70°C 24-Lead AD237JR 0 to + 70°C 24-Lead AD238JR 0 to + 70°C 24-LeadSOIC SOIC SOIC

AD236AN -40°C to +85°C 24-Lead AD237AN -40°C to +85°C 24-Lead AD238AN -40°C to +85°C 24-LeadPlastic DIP Plastic DIP Plastic DIP

AD236AR -40°C to +85'C 24-Lead AD237AR -40°C to +85°C 24-Lead AD238AR -40°C to +85°C 24-LeadSOIC SOIC SOIC

AD236AQ -40°C to +85°C 24-Lead AD237 AQ -40'C to +85°C 24-Lead AD238AQ -40°C to +85°C 24-LeadCerdip Cerdip Cerdip

AD236SQ -55°C to + 125°C 24-Lead AD238SQ -55°C to + 125'C 24-LeadCerdip Cerdip

AD239 AD24!

AD239JN 0 to +70°C 24-Lead AD24IJR 0 to +70°C 28-LeadPlastic DIP SOIC

AD239JR 0 to +70°C 24-Lead AD24lAR -40°C to +85'C 28-LeadSOIC SOIC

AD239AN -40'C to +85°C 24-LeadPlastic DIP

AD239AR -40°C to +85°C 24-LeadSOIC

AD239AQ -40°C to +85°C 24-Lead

Cerdip

AD239SQ - 55'C to + 125°C 24-Lead

Cerdip

OBSOLETE

)

)

)

)

)

14-Lead Plastic DIP (N-14)

04 8TPIN1 0.28017.111" 0.240 16.101

1 7 -1.. .

IV V 0.795 (20.19111 11 Ir-- 0.725118.421---1 0.06011.52)

.. ~ ,.," ,,~,

0.210

~15.33)SEATINGL-- - - - - - -

PLANE 0.20015.051

~ ~

to.150 (3.81)0.125 (3.181 l.

~~ -I i- 0.070(1.77)0.022 (0.5581 0.10012.54) 0.045 (1.1510.014 10.3561


""~~~:::::: ~I~:::::IV V V 0.840 (21.33) V V Ir--- 0.745118.931 10.060 11.521

-.-~.."'~'

0.210 ..(5.331 ----.

S~~~~O.~- - - - -

~

-

U

- t~~1~0.125(3.181 --L-,- ". . I I. 0.070 (1.771

-II'""" -I I'""" 0.045 (1.1510.02210.5581 0.10012.5410.01410.3561

16-Lead SOIC (R-16)

r-- 0.413(10.50)---1

I R R ,0.348(10.10)I R R-I~T0.29917.60)

0.291 (7.401

OUTLINE DIMENSIONS

0.325 (8.251

h10.30017.621.--Lr \ 0.19514.951

-~ ,T5 12.931

10.419 (10.65)

0.404 (10.26)

O.O50UUUUUUUU L11.27) -j I- -j I- 0.018 (0.46) t 0.364 (9.246)

jTYP 0.014 (0.361 0.344 18.738)+

6t::Jt::Jt::Jt::Jt::Jt::J~.i.~.id( ~ ~~====== t t T -+11-

0.010 (0.25) 0.015 (0.38) 0.045 11.15)0.004 (0.101 0.00716.18) 0.02010.501

14-Lead Cerdip (Q-14)

~: ~ ~ ~ ~ ~ I~I I:::I. 0.780 (19.81) -' . 0.300 17.6

~2)

r- ~ -1 r- REF

wmw '.'M"'"a0.133 (3.378)

~ 0.21+(5.33)

0.12~\~1711

L~3.81) 1f~

T--:[ +II.- -.J I- 0.012(0.305)0.0611.52) 0.0210.5) 0.1112.79) 0.008 (0.20310.05 (1.27) 0.016 (0.4061 0.09912.281


[~~~ ~~~I~::=:II 0.300(7.62)

r-0.780(19.81)~~14.14) ir-REF=iJ

~"~"m' ~--.~ 0.21 (5.33) 150

0.12~\~17)1

L~.81) o~

~ II I I- 0.01210.3051-+j -I t+- -t 0 008 (0.20310061152) 0.0210.5) 0.11(2.791 .

0:0511:27) 0.016 (0.406) 0.09912.28)

lO-Lead Plastic DIP (N-lO)

- ,~ ~ : ~ ~ : : ~ ~ : ~ I ~:;:;:IV V V 'u1.060 (26.901 11 V 11 Ir 0.925 (23.50) I0.060 (1.52)

.~ '.m"'"

0.210 .15.331 --,

S~~~~O~I - - - - - - -

~

-

~- t r:ilil01

0.125(3.18) i..

~i- -j I-0.02210.5581 0.10012.541 0.07011.781O~01410.3561 0.045 (1.151

-13-

OBSOLETE


f;:::,:I:,::::I~:~:::~i0.20 (5'0[J~ "kl(,10.14 13.56) 0.125 (3.18)

0.15 (3.81 - tJ 0.011 10.28)0.12513.18)

UII '

l

O'009(0.23)

,- ~ --H-- -J ~ "I0.02 10.5) 0.11 12.79) ~

0.016 10.411 0.09 (2.28) 00.07 (1.78)0.05 (1.27)

LEAD NO.1 IDENTIFIED BY DOT OR NOTCHLEADS ARE SOLDER OR TIN-PLATED KOVAR OR ALLOY 42

24-Lead Plastic DIP (N-24A)

10.55 (13.911

J3.411

I VVVVVVVVVVVV I

1.25 (31.15) 0.606 (15.41

L . 1.24131.5) . ~r--D~I I

u~ ...~,Ir ,I15.081 ~MAX =---*- ~~ 0115(4451 D.OI2(D.305)

J l ~.12(3.;") t 0.008(0.203) ~-01j.- ...j I- --r

0.065 (1.66) 0.02 (0.5081 0.105 (2.6110.45 (1.151 0.015 (0.38" D.'" (2.421


f0.260 ...00116.61 .0.031

---1.

I 1=131.19) I. 1.226(31.14) 1.

~.~~0.128(3.251

SEATI~- - - - - - - - - - -- - ---,

PLA -.j fo- -.j fo- j L --{.0.0210.51 0.1112.79' 0.07(1.78)

0.01610.41) ii]9jffij 0.0511.271

NOTES,. lEAD NO.1 IOEN""ED 8V OOT OR NOTCH.

2. PLASTIC LEADS WILL 8E EITHER SOLDER DIPPED OR TIN lEAD PLATEDIN ACCORDANCE WITH Mll.M.38510 REOUIREMENTS.

24-Lead Ceramic DIP (0-24)

..r::'~[~I~ : r~~

I I 10-- 0.610"5.491 I, 1.200(32.77) . 0.07511.911L_..~_I

.~--I~~ ~

SEA.zl~--'-- - - - -- - - - - - - -- 0.150 0.01510.38'0.200 15.G8I

J Lf 13.811 II 0.00810.20'

0.120 (3.051 ---1.. U~ II 0.

.02310.58' I I 0.07011.78' I 0.620 (15.751 I

""Ir+-001410.361 -t r+- 0.03010.76' "'--0.59011499'---"0.11012.791

0.090 12.291


[::~~::::]JI I 0.3208128

~. 1.200(32.77IMAX. 1 0.200(7.3661

,J;;'~ <- =15.715) 14.572)MAX ~X

SEATlNG~ - - -- - - - - - - - - :::;:-t --PLANE 0.125 T 001210305113.1751

j L~ II

I0:00810:203,

MIN 0.02010.5081 U TV'

~~ -.j fo- --{~~~:i~;~~: ~~:g::: ~~~i:;;:: 1fTVP TVP

,. lEAD NO. llDENTlAED 8V OOT OR NOTCH.

2 CERDIP lEADS WILL 8E EITHER TIN PLATED OR SOLOER OIPPEDIN ACCORDANCE WITH Mll.M.3"'0 REQUIREMENTS.

-14-

OBSOLETE

)

)

)

)

:~:Jr~~ ~ ~ ~ ~;:'::o:c;;~~, :+j~ ~ ~ ~ ~ ~ ~ ~ ~~ ~ ~ ~ ~I~.~::

.,:: '.'"

I I. ~ .- ,,-, .1..""" .. .".

I

~ "696(17671 --L -+jt+- 0.01310.321-'u r--, ,..,_.

0608(15.451 0.0'612.441 00210.511 ~-iI.~ ~ ~ ~ ~... "." .~. ~, ., ,.. ".., l1J-1J-1J-1J-1J-1J-1J-1J-1}-1}-1J-1HI-1JL*,T,~ I"r--- , , I~ ~, " -II- """", 0 -- 10-~~ L~,J. ~ I- 0

.01910

.491 0.00610151 0..0421'

.

0671

-'fT -F-.c j I! 00511271 00141035) 0018104571

I I -II- 0.01 10.2541

-+f t- ~ 000610151 0.04211.05710.05 (1.271 0.'014 (0.351 " 0.018 (0.4571

28-Lead SOIC (R-28)

,. LEAD NO.1 IDENTIFIED BY A DOT.

2. SOIC LEADS WILL BE EITHER TIN PLATED OR SOLDER DIPPEDIN ACCORDANCE WITH MIL.M.'851O REQUIREMENTS.

,. LEAD NO. "DENTIF'ED BY A DOT

2. SOIC LEADS WILL BE EITHER TIN PLATED OR SDLDER DIPPEDIN ACCORDANCE WITH MIL.M.'851O REQUIREMENTS

-15-

-~ -

OBSOLETE

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