MC1506L - Motorola / Freescale Semiconductor

specifications and Applications

Information

SIX BIT, MULTIPLYING

DIGITAL-TO-ANALOG CONVERTER

designed for use where the output current is alinear product

. . .

of asix-bit digital word and an analog input voltage.

CERAMIC PACKAGE

CASE 632

TO-116

FIGURE 2 – D-to:A TRANSFER CHARACTERISTICS

2.0 v

OmA

2.0 mA

‘.0 mA

.0 mA

(000000) IN PUT WORD (111111)

TYPICAL ‘APPLICATIONS

eTracking A-to-D Converters

eSuccessive Approximation A-to-D Converters

,a Digital-to-Analog Meter Readout

oSample and Hold

ePeak Detector

eProgrammable Gain and Attenuation

@Digital Varicap Tuning ,

eVideo SVstems

Stepping Motor Drive

CRT Character Generation

Digital Addition and Subtraction

Analog-Digital Multiplication

Digital-Digital Multiplication

Analog-Digital Division

Programmable Power Supplies

Speech Encoding

MDTL and MTTL are trademarks of Motorola Inc. (MC1506– Page 1) @MOTOROLA INC.. 1974 D,S 9232 R1

,’

MAXIMUM RATINGS (TA =+25°C unless otherwise noted.)

Rating Symbol Value Unit

Power Supply Voltage Vcc +5.5 Vdc

VEE -16.5

Digital Input Voltage V5thru V10 +8.0, V~E. Vdc

Applied Output Voltage Vo *5. OVdc

Reference Current 112 5.0 mA .-:\.:$,,

Reference Amplifier Inputs V12,V13 Vcc, VEE Vdc 1~~~:~..}tt:$~,

.:**,. ‘.JL,,

Power Dissipation (Package Limitation}

pD .r:~,.l

~.,!

Ceramic Package >>~, .<,

I1000 *,$\\’&w:t<++

Derate above TA =+25°C 6.7 ,, *.flJ@k

Operating Temperature Range -

TA K{:*,$,?y’~““

MC1506L .1.*>.$*\t..,,

-55 to +125 :$ ,* ,$.,!‘“ Oc

>., .,.,

MC1406L oto +70 .:**,“.i)ij?

...

Storage Temperature Range Tstg -65 to +15$~:<~~,, Oc

~\\,.!.

**. ‘.*.,*4.

,*,\m$~,l

\. ,.$it!

$’rt}.:r:,,~l$..

,’ ‘)..

~’}>.>f,’~~

‘“’%

‘$i*:&;,,.t,:;!$:\\ 1

Characteristic Figure Max Unit

Relative Accuracy (Error relative to full scale 10) 10 YO.78 %

Settling Time (within 1/2, LSB [includes tdl TA =+25°C) 9300 ns

Propagation Delay Time 9,5;

TA =t25°C 50

,.,.:,;,:,< ns

.>.’.,?,

Output Full Scale Current Drift ,e’,.~,‘:~’i~<,~,

,* Z:p? ‘‘Tc’o’ -80 – PPM”/°C

.:,,.

Digital Input Logic Levels Vdc

Q.,

High Level, Logic “l” ,\.\.*,.~’, VIH 2.4 — —

Low Level, Logic “O” .:.: VIL — —

,(:> 0.8

>..,.?

.,:!*).

Digital Input Current .. ‘.+.,,,,

\~A\

s,, .~$.. 3,13 mA

High Level, VIH =5.0 V.+,,<,

~.i!?).!$,.,:$3:> IIH —0“ +0.01

.\ ‘i.,t

Low Level, VIL =0.8 V.}’. ,, $,

,,).:

~\~,,,,* ,,~?: IIL —-0.7 -1.5

Reference Input Bias Current (Pin’13) 3113 – -0,002 4.01 mA

Output Current Range 3IOR mA

VEE =-5,0V ... ~,~.

,,:?I:,,tt; o2,0 2.1

,r.$~:..~

VEE =-6. Oto -15 V-~:qlg.:,.

~. ,,..~

::., th o2.0 4.2

,,..

Output Current “.~~~.’~~,t.,)):?,.<’,

,).~ ~.,3..

.&\;. 3 10 mA

Vref =2.000 V, R12 =1.000 k~ $:, ,# 1.9 1.97 2.1

,.,..:.~<.:.~:,,‘,\’*,,.\.

Output Current >,* .~,

‘t~~$s*,,, 3Io(min)

(all bits high) $..

~.>:\3 PA

‘,kt —o10

Output Voltage Compli~~~:Jf

3,4,5 Vo+ –+0,25

(Er<+0.78% at ~$~$$~5bC} +0.1 Vdc

vo- –:0,45 -0.3

Reference Cur~~n~j~j~+ Rate 8,15 SR Iref mA/ps

(TA =+25°~?$$~. ‘$s+ —2.0 –

.:,/.,5

Output,$u.&$gtt#ower SUPply Sensitivity 10 PSRR(–) –

->,\.,\ 0.002 0.010

,,. mA/V

Powerl*.@~ Current ,3,11,12

&~;$$$fi6; VI L=O.% VmA

Icc —+7.2 +11

AQ#hru A6;VIH =2.4V IEE —-9.0 -11

Power Dissipation (all bits high) IpD mW

VEE =-5.0 Vdc —85 120

VEE =-15 Vdc —175 240

‘Thigh =+70°C for MC1406L T{ow =O°C for MCI 406L

=+125°C for MCI 506L =-55°C for MC1506L

@MOTOROLA Semiconductor Products inc.)

The MCI 506L consists of areference current amplifier,

an R-2R ladder, and six high-speed ,current switches. For

many applications, only areference resistor and areference BLOCK DIAGRAM

supply voltage need be added. MSB LSB

The switches are inverting in operation, therefore alow Al A2 A3 A4 A5 A6

state at the input turns on the specified output current ? T

component. The switches use acurrent steering technique CURRENT SWITCHES

for high speed and atermination amplifier that consists of

an active load gain stage with unity gain feedback. The

termination amplifier holds the parasitic capacitance of the R2R LADDER

ladder at aconstant voltage during switching and provides I

alow impedance termination of equal voltage for all legs (+I

of the ladder. Vr,f o

The R-2R ladder divides the reference amplifier current l-l BIAS’CIRCUIT

into binarily-related components which are fed to the Vrel o

‘@

-MOTOROLA Semiconductor Products Inc.

(M C1506– Page3)

TEST CIRCUITS AND TYPICAL CHARACTERISTICS

FIGURE 3- NOTATION DEFINITIONS TEST CIRCUIT FIGURE 4 – OUTPUT CURRENT versus OUTPUT VOLTAGE

Vcc g

iIcc

()11 Pa

[z -~~= “ - J J “:: -

1,2 A1= Low

5R12 +z2.0 A2.A6 =High .’:$,}).,~

Vo RANGE FOR \

66.BIT ACCURACY .,;$}~::?;>~,>,,:,>,~

@25°C .. .>:,,:,.,,

>+:.’ .~~..s.~‘.*

DIGITAL A3

INPUTS 6

‘[{:? ~uTpuT ~’:“: ; .! .1 :$ 6“: :.

-v

VI and II apply to inputs Al If IEE

thru A6 10=K{~+~+~+:+~+~}=K{~}

VEE where ~~&f

R12

and A—N=Oif AN isat high level

TN =1if AN isat IOWIavei

FIGURE 5 – MAXIMUM OUTPUT VOLTAGE

versus TEMPERATURE

L.u

A5 g

A6 10 I

It4“

I%1 Vn

VEE

FIGURE8 –REFERENCEC URRENTSLEW RATE

MEASUREMENT TEST CIRCUIT

VEE

—

8MOTOROLA Semiconductor Products inc-

(MC1506 –Pege4) ,

TEST CIRCUITS and TYPICAL CHARACTERISTICS (continued)

FIGURE 9 – TRANSIENT RESPONSE

2.0 Vdc

“5 I1\2- lk

:O.IPF

einm MC506LR50PF’

:55 050 100 125

FIGURE 12 – TYPICAL POWER SUPPLY CURRENT versus VEE

Vcc=t5.ov

E9.0

~B.O

vIEE–ALL BITS HIGH

~I-—

~7.0 IEE –ALL BITS LOW

sICC–ALL BITS HIGH

Q6.0 I— —

Icc– ALL BITS LOW

&r <<

04.0 -6.0 -8.0 -lo 12 14 16 ‘J

T, TEMPERATURE(°C) VEE, NEGATIVE POWERSUPPLY(Vdc)

m~O~O~Ok~ Semiconductor Prwducts Inc.

TYPICAL CHARACTERISTICS (continued)

FIGURE 13– LOGIC lNPUT CUR RENTversus INPUT VOLTAGE

1.0 ,

\’

0.8

0.6 1

0.4 \

0.2 \

or, \

,, 01,0 2.0 3.0 4.0 5,0 ‘6.0 7.0 8.0

Vin, LOGIC INPUT VOLTAGE (VdC)

FIGURE 14 – MSB TRANSFER CHARACTERISTICS

versus TEMPERATURE (MSB IS “WORST CASE”)

GENERAL INFORMATION

Output Current Range

The output current maximum rating of 4.2 mA may be

used only for negative supply voltages below -6.0 volts,

due to the increased voltage drop across the 40Q-ob

i:;:,yai~,.

resistors in the reference current amplifier. ,.,:+>+?

~..~,,

~.~.,,.:!.~$.*

The MCI 506L current switches hav?i:~$:~~signed for

high-speed operation and as a result:~~.~:$?stricted out-

put voltage range, as shown in Fig~k$:~# and 5. When a

,;].

current switch is turned “oft’~ ‘h~he ~ollower emitter is

“~$,%~,..},,.,

near ground and apositive$~&l$’*”:bn the output terminal

can turn “on” the out~d$<,$?\@e and increase the outpu?

~:*,,

current level. When ~~~~]:~~! switch is turned “on”, the

negative output va!~ag~i~%ange is restricted. The base of

,$ $

the termination &g8wi$ Darlington amplifier is one diode

,f’o’T.::*,“<:/%.

voltage below g~u%d; thus anegative voltage below the

.. +$\~

specified .&Sfg*AI will drive the low current device of the

~..),*$?

Darlint~ton’:~pto saturation, decreasing the output current

LL_.–[_J._.l ...__J_._ti_~l

f, FREOUENCY (MHz)

—

~?>+i

~“>& example, at +25°C the allowable voltage compliance

?..~

‘maximum resistor value that can be connected from Pin 4

to ground is 1500hms.

Accuracy

Absolute accuracy isthe measure of each output current

level with respect to its intended value, and is dependent

upon relative accuracy and full scale current drift. Relative

accuracy is the measure of each output current level as a

fraction of the full scale current. The relative accuracy of

the MCI 506L is essentially constant with temperature due

to the excellent temperature tracking of the monolithic

resistor ladder, The reference current may drift with

temperature, causing achange in the absolute accuraqy

of output current.

The best temperature performance is achieved with a

-6.0 Vsupply and areference voltage of -3,0 volts. These

conditions match the voltage across the NPN current source

pair in the reference amplifier at the lowest possible volt-

age, matching and optimizing the output impedance of

the pair.

The MCI 506 L/MCl 406L is guaranteed accurate to with-

id ~1/2 LSB at +25°C at afull scale output current of

1.969 mA, This corresponds to areference amplifier out-

put current drive to the ladder of 2.0 mA, with the loss of

one LSB =31 PA that is the ladder remainder shunted to

grou~d. The input current to Pin 12 has aguaranteed

current range value of between 1.9 to 2.1 mA, allowing

Semiconductor Prodwcts Inc.

(MC1506 –Page 6)

GENERAL INFORMATION (continued)

some mismatch in the NPN current source pair. The around circuit or current mirror for feeding the ladder.

accuracy test circuit is shown in Figure 10. The 12-bit The reference amplifier input current, 112, must always

converter is calibrated for afull scale output current of flow into Pin 12 regardless of the setup method or re+~,,rence

1.969 mA, This is an optional step since the MC1506L voltage polarity. ;,.,.,‘::,$

.*$.,‘s...~y~ik,,,,

accuracy is essentially the same between 1.5 to 2.5 mA. ~,..‘~e.~

Connections for apositive reference volt~~~$<’~hown

Then the MC1506L full scale current .is trimmed to the in Figure 6. The reference voltage source8,~,~~& the fu II

same value with R12 so that azero value appears at the current 112. Compensation is accomplis&@R~Niller feed-

error amplifier output. The counter is activated and ‘the back from Pin 14 to Pin 13. This @~@p###ation method

error band may be displayed on an oscilloscope, detected yields the best slew rate, typica$~@~$@’ than 2.0 mA/ps,

by comparators, or stored in apeak detector.’ and is independent of the val~f o*l@#2. R13 must be used

Two 6-bit D-to-A converters may not be used to con- to establish the proper i@,@~nce for compensation at

struct a12-bit accurate D-to-A converter. 12-bit accurac\/ s,>.‘?*

Pin 13. For bipolar ref,~~,%~s~nals, as in the multiplying

implies atotal error of *1/2 of one part in 4096, or mode, R13 can be ti~~~~~jnegative voltage corresponding

@.01 2%, which is more accurate than the kO.78% specifi- to the minimum i@*~j:’Mvel. Another method is shown

cation provided by the MC1506L. ‘x:>

in Figure 22. .. .

~i.’~’..s

It is possl~k~~~e.~liminate R13 with only asmall sacri-

Multiplying Accuracy ,.,.,. ~?,~it}

fice in ac~ur$$y~nd temperature drift. For instance when

‘The MC1506L may be used in the multiplying mode high-$R$q~i@-ration is not needed, acapacitor is connected

‘: ‘$

with six-bit accuracy when the reference current is varied fr~m &%$J4to VEE. The capacitor value must be increased

over arange of 64:1, The major source of error is the $’h~ RI 2is made larger to maintain aproper phase

bias current of the termination amplifier. Under “worst ,, ~~’~rg;n. For RI 2values of 1.0, 2.5, and 5.0 I<ilohms,

“’’”“$ti’inimum capacitor values are 50, 125, and 250 pF.

case” conditions these six amplifiers can contribute atotal +.,~q~$,,,

of 6.0 HA extra current at the output terminal. If the “’”~~~~~ Connections for anegative reference voltage are shown

...

reference current in the multiplying mode ranges,,fro~$k in Figure 7. Ahigh iriput impedance is the advantage of

60 MA to 4.0 mA, the 6.0 MA contributes an .~$~~~$i,,of this method, but Miller feedback cannot be used because

0.1 LSB. This is well within six-bit accuracy. .$w’~$m, “it feeds the input signal around the PNP directly into the

Amonotonic converter is one which supp~$~~pa~:~ncrease high impedance node, causing slewing problems and high

in current for each increment in the bin~~{~~$~. Typi- frequency peaking. Compensation involves acapacitor

., ‘.?\.\s#\\‘\?’

tally, the MCI 506L is monotonic for alh~~~~~of reference to VEE on Pin 14, using the values of the previous para-

!>\>,,l.i,ii

current above 0.5 mA. The reg~~~~nded range for

,., ‘iJ:{ .$‘graph. The negative reference voltage must be at least

operation with adc reference cu@ent\?w8.5 to 4,0 mA. 3.0 Vabove VEE. Bipolar input signals may be handled

,,.~~‘~+

,,*T,.

,.,:,.>:<,?,,,,~.\.J,4+$’, by connecting R12 to apositive reference voltage equal to

Settling Time ,~~: if,

‘.:,i+s,.>.,$:-i’ the peak positive input level at Pin 13.

..*+~fllj$!.,.,,

The “worst case” sW~~ch@g condition occurs when ali When adc reference voltage is used, capacitive bypass

bits are switched “~~*~: “‘s’

wh~eh corresponds to ahigh-to-low to ground is recommended. The 5.0 Vlogic supply is not

transition for all~~~lF’This time is typically 150 ns to recommended as a reference voltage. If awell regulated

within ~1 /2 &,~QK$,~~le the turn “off” is typically under 5.0 Vsupply which drives logic is to be used as the refer-

50 ns. <.:jll<.

‘~~):~,,\\~..\.~ ence, R12 should be decoupled by connecting it to +5.0 V

..\

The,Y,&~~~S~ single switch is the least significant bit, through another resistor and bypassing the junction of

which$~ur~ “on” and settles in 5d hs and turns “off” in

‘,!,>s,,.,,:?!the two resistors with 0.1 UF to ground. For reference

3Q~~ii..,U,fn applications where the D-to-A converter func-

.%~.~~‘*:voltages greater than 5.0 V, aclamp diode is recommended

=XW,o*:in apositive-going ramp mode, the “worst case” between Pin 12 and ground.

.:,\i,$,~.>$+y

~’itching condition does not occur, and asettling time If Pin 12 is driven by ahigh impedance such as a

of less than 150 ns may be realized, tra~sistor current source, none of the above compensation

Reference Amplifier Drive and Compensation methods apply and the amplifier must be heavily compen-

sated, thus decreasing the overall bandwidth.

The reference amplifier provides avoltage at Pin 12 for

converting the reference voltage to acurrent, and aturn-

—@MOTOROLA semiconductor Products Inc.

(MC1506–Page7)

,. APPLICATIONS INFORMATION

FIGURE 16- OUTPUT CURRENT VOLTAGE CONVERSION

MSBAl

LSBA6

3,. *v~~f VTef =2.0 Vdc ‘

13m R12=R13sl,0kQ

7MC1506L ,4 20PF& GRO=5,0k Q

aMC1406L ‘RQ

&NC

92“ ‘~

,—

4~ 10

—

and input

compensation. Res*~~~F this circuit is also on the

\order of 2.0 vs. .$$@$M&orola Application Note AN-459

for more detail:,~$&s concept.

s+?’‘$’,.:.,,k;.

Voltage outputs of alarger magnitude are obtainable ,.:,, 1%

;i .:.+, ,{/, FIGURE 18

with this circuit which uses an external operational ampli- ‘. ,!*.*.+,,:.>t}~.,,,.

~~:~,>:.$.

~J,\l.,

fier as a current to voltage converter. This configuration +@~ .

\+,>,

‘*

t15v 35pF

automatically keeps the output of the MCI 506L at ground “...s

“-$:,,.

.’i’’*’$tJ,,.

potential and the operational amplifier can, generate a..\- ~.~,.

k.’. ~:’,i 5k

1:~-\

positive voltage limited only by its positive supply voltage. .R,jl.,,,,>.!y

.~$;,,,....&.\.y:.y.

FYequency response and settling time are primarily deter- ,

...... ~.‘..,,!,,

?<,:., 710k

mined by the characteristics of the operational amplifie~ \\,;<!:.

In addition; the operational amplifier must be compens~,~~~?

for unity gain, and in some cases overcompensati~a~~ ~

be desirable. .,.3$ ‘f’:l*&

.++’..!.’$’

Note that this configuration results in apos~i~~~titput

.,.<?*.\,‘k,

voltage only, the magnitude of which l+.:~#Rqdent on

the digital input. .,., “:$ ‘*”

\.,:,

The following circuit shows how~~~e,@~~301AG can

be used in, afeedforward mod~~%~lt{fig in afull scale

settling time on the order of 2$Q,~~&~:?

,,\,~,.*

,,:*.

of MC1506L) 3MC1539G

240 ~t

0.2 PF 7;4( )

f~e

=-15 v

The positive voltage range may be extended by cas-

coding the output with ahigh beta common base tran-

sistor, QI, as shown.

‘A

Vcc

alo

i5k

MC1506L al Ge

The output voltage range for this circuit is Ovolts to

BVCBO of the transistor. Variations in beta must be

considered for wide temperature range applications. An

inverted output waveform may be obtained by using a

load resistor from apositive reference voltage to the

collector of the transistor. Also, high-speed operation is

possible with alarge output voltage swing.

m) MOTOROLA Semiconductor Prodwcts inc.

APPLICATIONS INFORMATION (continued)

Combined Output Amplifier and Voltage Reference

For many of its applications the MC1506L requires a

reference voltage and an operational amplifier. Normally

the operational amplifier is used as a current to voltage

converter and its output need only go positive. With the

popular MCI 723G voltage regulator both of these functions

are provided in asingle package with the added bonus of

up to 150 mA of output current, see Figure 19. Instead

of powering the MCI 723G from asingle positive voltage

supply, it uses anegative bias as well. Although the refer-

ence voltage of the MCI 723G is then developed with

respect to that negative voltage it appears as a common-

mode signal to the reference amplifier in the D-to-A con-

verter. This allows use of its output amplifier as a

classic current-to-voltage converter with the non-inverting

input grounded.

Since i15 Vand +5.0 Vare normally available in a

combination digital-to-analog system, only the -5.0 V~

need be developed. Aresistor divider is sufficiently accu-

rate since the allowable range on pin 5is from -2.0 to

-8.0 volts. The 5.0 kilohm pulldown resistor on the ampli-

fier output is necessary for fast negative transitions.

Bi~lar or Negative Output Voltage

The circuit of Figure 20 is avariation from the standard

voltage output circuit and will produce bipolar output

signals. Apositive current may be sourced into the sum-

ming node to offset the output voltage in the negative

direction. For example, if approximately 1.0 rn$~~,ssed

abipolar output signal results which ‘may @‘&~~~bed

,$$’,,p;t,’~+

as a 6-bit “1 ‘s” complement offset binary,:,, +~(~fmay be

used as this auxiliary reference. NoteaX~@~Q has been

Full scale output may be increased to as much as 32 volts ~, “~~,, u

20pF ~,~ &d-15 v

,fi<”%~k,a,.,,

by increasing RO and raising the t15 Vsupply voltage to ....: ‘?:/:.

.f+

$I:k

~$i.>.*:::p::.,:~

35 Vmaximum. The resistor divider should be altered to ~Ftm;.:&, Vref %1 X2 %3 54 15 X6

VO=~(~O)( y+~+~+K +z+til-~f(ROl RB

comply with the maximum limit of 40 volts across the >9$‘.. ~

~.’;:,

MCI 723G. Co may be decreased to maintain the,:.~ame<$

ROCO product if maximum speed is desired. ‘~””’’1~~$,,

\*,

‘-.~,>,~~.>,,

~:’:.l$.iy\*<h,,,

,1$~T

~: ,..\

Programmable Power Supply . ., ,,:{,,

,p~~,.

,,..>.Y..,’::,,,~. Polarity Switching Circuit, 6-Bit Magnitude Plus

The circuit of Figure 19 can be u$~,$$w’digitaily Sign D-to-A Converter

programmed power supply by the addi~~~~~$thumbwheel

.,/l>$‘is Bipolar outputs may also be obtained by using apolarity

switches and aBCD-to-binary con,~,$#k:r&~The output volt- switching circuit. The circuit of Figure 21, gives 6-bits

age can be scaled in several ways~lnc$fing Oto +6.3 volts

... magnitude plus asign bit. Inthis c~nfiguration the oper-

in O.I-volt increments, *0.O@*’&~&br Oto 31.5 volts in ational amplifier is switched between again of +1.0 and

0.5-volt increments, M. ~$J~@$.J -1.0. Although another operational amplifier is required,

~:~,. ‘....!

.~.\. ..

FIGURE 19 – C~BIN~@ OUTPUT AMPLIFIER and no more space is taken when adual operational amplifier

VOL~&& QEFERENCE CIRCUIT such as the MCI 558G is used. The transistor should be

selected for avery low saturation voltage and resistance.

Ro=5k

MS, Al 5;; *3’ ‘f!& ‘“ 11 \l 4)FIGURE 21 – POLARITY SWITCHING CIRCUIT

A2 ;; $—— —

NC r

~$$, ~:,,.. ~c150cL i

4Nc ‘d MC1723G {G-Eit Magnitude Plus Sign D-to-A-Converter)

A,,,,‘%%$ ,:. MC1406L 4

j~~~

*VO

10 k

:.. FROM Vo R

OUTPUT e2

OP-AMPL 10k

20 pF 1/2 MC155SG VO=VOF –VOP

tRor Equiv

=R13 4

10 k

1.6 k3.6 k

P=l: A.=-l

=7.1 VMP36514 P=O Av=+l

CONTROL BIT ,, Equiv

“L–__J =5k

Pl.tik

‘o=vrel %{~} ~~

Settfing time I,r 10 Vstep e1.OP

vEE -15 V

@MOTOROLA Semiconductor Prodwcts Inc.

.APPLICATIONS INFORMATION (continual)

Programmable Gain Amplifier or Digital Attenuator

When used in the multiplying mode the MC1506L can

be applied as a digital attenuator. See Figure 22. ‘One ad-

vantage of this technique is that if Rs =50 ohms, no

compensation capacitor is needed and awide large signal

bandwidth is achieved. The small and large signal band-

widths are now identical and are shown in Figure 15.’

FIGURE 22– PROGRAMMABLE GAIN AMPLIFIER OR

DIGITAL ATTENUATOR CIRCUIT

vref Wh,n VS=D, l12=2mA

R12 ,0 vo=[~ *$] {x} R,

Vs 4

13 )+15 Vdc

MC1508L

MC1406L NC

IMC1741

=5678910

Al A2 ‘A3 A4 A5 A6

‘;-.::3$\<;.?j,,.

Panel Meter Readout ., i~: ... .

~~::>

The MCI 506L can be used to read out QW~@~~$~j of

BCD or binary registers or counters in a,$~~~~,’iontrol

system. The current output can be used~k~’”~~e directly

,?,,

an analog panel meter. External ~~t~:f~:unts may’ be

necessary if ameter of less than 2.@@~full scale is used.

**;,.*.+2;,Y.V*

Full scale calibration can be don~j~y @justing R12 or Vref.

10=10-102= V% {z} -“~ {B}

Dig, tal.Subl, action:

,,tVreil _vref2

R12, R122

V,= ~RO I{X} -{5}]

Programmable Amplifier,

Connect digital inputs so A=B

mMOTOROLA Semiconductor Products ffnc.

This digital subtraction application is useful for indi-

cating when one digital word is approaching another in

value. More information is available than with adigital

comparator.

Bipolar inputs can be accepted by. using any of the

previously described methods, or applied differentially to

R121 and R122 or R131 and R132. VO will bea bipolar

signal defined by. the above equation, Note that the circuit

shown accepts bipolar differential signals but does not have

anegative common-mode range. Avery” useful method is

to connect R121 and R122 to apositive reference higher

than the most positive input, and drive R131 and R132.

This yields high input impedance, bipolar differential and

common-mode range. The compensation depends on the

input method used, as shown in previous sections.

,w(M C1506 –Page 10)

APPLICATIONS INFORMATION (continued)

FIGURE 25 – DIGITAL SUMMING and CHARACTER FIGURE 26 – PEAK DETECTING SAMPLE and HOLD

GENERATION (Features infinite hold time and optional digital output.)

5676910 Ro

R121 IZ

Vrell —101

MC1506L 4~

R131 13 MC1406L 14 CLOCK DETECTIHOLD

vu REsET

—see

12 11 3 t,.? =

NC =COMPARATOR

VCC vEE VO=IIOI+.IOZ)RO (-t BINARY COUNTER

—=~ {x}+ ~{,}] R,

NC ,—+

2113

R122 ,2

v1ef2 wRo

MC1506L ,4

R13z ,3 MC1406L -102

—14

,0 Se, ~,xt

56789 Vo @

B—

Inacharacter generation svstem one MC1506L circuit uses a

fixed reference voltage and its digital input defines the starting

point for astroke. The second converter circuit has aramp input \\ i~,

for the reference and its digital input defines the slope of the Positive peaks may be detected ~~’~~erting ahex inverter between

stroke, Note that this approach does not result in a12-bit D-to-A +‘,::\x

the counter and MC1506~,’k~$Ing the comparator inputs, and

converter (see Accuracy Section), connecting the output a@i$@r Fdr unipolar operation.

......>

*.}$~“$.;~!,,\\,,,,.

FIGURE 27 – PROGRAMMABLE PULSE GENERATOR FIGURE 28 – PROGR~f

w/n

Current pulses, ramps, staircases, and sine waves may be generated

‘amps by the appropriate digital and reference inputs, This circuit is

!rance especially useful in curve tracer applications.

-, —

A101 Hill

Vref= ~,, --- .,.. B

This circuit yields the inverse of adigital word scaled bv a5A6A7A8AgA’”A L=

constant. For minimum error over the range of o~ration, 10 can ~ = -_.. —

be set at 62KA so that 112 will have amaximum value of 3.938 mA

for adigital bit input configuration of 111110.. 1~1 ,1nl.1= .ICL

Compensation is neceswrv for loop stability and depends on !Oz=gz {E}

the tvpe of operational amplifier used. If astandard 1.0 MHz H

operational amplifier is employed, it should be overcompensated

when possible. If this mnnot be done, the reference amplifier

mn furnish the dominant @le with extra Miller feedback from ,}

pin 14 to 13, If the MC1723 or. another wideband amplifier is

used, the reference amplifier should alwavs be overcompenwted.

m‘MOTOROLA semiconductor Products nnc.

,’

APPLICATIONS INFORMATION (continued) OUTLINE DIMENSIONS

FIGURE 31 – ANALOG PRODUCT OF TWO DIGITAL WORDS

(High-Sped O~ration)

101

150<1

R121 12

V,ef ~13 &NC 4NC

MC1506L 2-13 MC1506L

MC1406L 342

43-

R13 5678910 5PF

.~ —

A‘0=’01’0=%; {~}’oB

,02=!B}Ivol

=g[,o () {,}]

SinceRO =R122amdK=v(~f/R12,

m’ Kcan be an analog variable.

Two Dgit BCD Conversion

MCI 506L parts which meet the specification for 7-bit

accuracy can be used for the most significant word when

building atwo digit BCD D-to-A or A-to-D converter. If

both outputs feed the virtual ground of an operational

amplifier, 10:1 current scaling can be achieved with a

resistive current divider. If current output is desired, the

units may Woperated at full scale current levels of 4.0 mA

and 0.4 mA with the outputs connected to sum the curre~~~,,

The error of the D-to-A converter handling the least+.~ig+

Vi” mIb=

-LSB

11 9

R12 *I

Vref ~-12 B

MC1506L

~13 HEX

MC1406L &INVERTER

1( ~14 6

20PF 5

Rf3 MSB