Advance Information
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9
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ELECTRONIC TELEPHONE CIRCUIT
Provides All Basic Telephone Station Apparatus Functions in a
Single IC, Including DTMF Dialer; Tone Ringer, Speech Network
and Line Voltage Regulator
DTMF Generator Uses Low-Cost Ceramic Resonator with Accu-
rate Frequency Synthesis Technique
Tone Ringer Drives Piezoelectric Transducer and Satisfies EIA
RS-470 Impedance Signature Requirements
Speech Network Provides Two-Four Wire Conversion with
Adjustable Sidetone Utilizing an Electret Transmitter
On-Chip Regulator Insures Stable Operation Over Wide Range
of Loop Lengths
12LTechnology Provides Low 1.4Volt Operation and High Static ,.~$~’
Discharge Immunity ‘Ii?..,.’,
‘.+.,,
“.,
Equalization Provided to Compensate for Long/Short L~#&, .)}
Performance :$.q~., *:
*,,
Order this data sheet bv MC34011WD
MC34011A
FN SUFFIX
44-PIN PSUFFIX
PLCC PLASTIC PACWGE
CASE 777-01 CASE 711-03
/$(: Hook Switch
Piezo r)
/
– – –––– __ /
12 3 A
L———
1
~
Speech
Network
———— ---- _-
1I
I
II
M’
Line
doltage Io
Regu- Ring
Iator :
I
I
I
.—-— JI
Receiver vMC34011A
Electret
Microphone >—
lis document contains information on anew product, Specifications and information herein OMOTORO~ INC., 1987 AD1745R2
are subject to chanae without notice,
,,, ,! !,, ,,
,,, ,
,, ,:,
MAXIMUM RATINGS (Voltage References to V-, )FIGURE 2—PIN CONNECTIONS
Parameter Value Unit
V+ Terminal Voltage (Pin 34) +18, –i)o v’
n
,Rl 140 TRF
VR Terminal Voltage (Pin 29) +2.0, –1.0 vR2 239 TRO
RXO Terminal Voltage (Pin 27) R3. 3TRI
+2.0, –1.0 v38
R4 437 TRS
TRS Terminal Voltage (Pin 37) +35, –1.0 vcl c536 3
TRO (VVith,Tone Ringer Inactive) Terminal Voltage +2.0, –1.0 vC2 c635 3
RI-R4 Terminal Current (Pins 1-4) *loo C3 c734
mA
CI-C4 (Pins 5-8) :C4 c 8
Operating Ambient Temperature Range E9
–20to +60 “c c 10
Storage Temperature Range –65to +150 ‘c c 11
GENERAL CIRCUIT DESCRIPTION
,,
Introduction ‘,
The MC34011A Electronic Telephone Circuit (ETC)
provide all the necessary elements of atone dialing ,1
~:<
t:,, ,,,:.:,,
telephone in asingle IC. The functional blocks of the \i>:~
p$ *;,‘+<,a~. {TOPView)
ETC include the DTMF dialer, speech network, tone .,7~,$”
.>>:
,..;4, ,,,., Lo_~O
ringer, and dc line interface, circuit (Figure 1). ~r: emm.mmmu~
.,\..‘:.:}..
~.t$t:, Cm Km++ K++
Low voltage operation is anecessity for telephones $@WJ~‘nmmnmnnnnn n
[o1
in networks where parallel telephone connections are Ii. ,,
‘.S,l>.-.*,..,~.* cl E3
common. An electronic speech network operating in ~,:;:.
.:*}..,!>,;\&,&
,1~,, C2 E3FB
parallel with aconventional telephone may receive line ,., “C3 E3v+
voltages below 2.5 volts. DTMF dialers operat~pt ‘8’ C4 E1BP
similarly low-line voltages when signaling thr~ug%:!, E3LR
battery powered station carrier equipment. TJWi]~w t(Top View) 1LC
voltage requirements have been addressed @,,~&q~Wing [1 v-
the MC34011A in abipoiar/12L tech$~$~~~with [1VR
appropriate circuit techniques. The resU~~~~@eech and c 1 CAL
dialer circuits maintain specified ~qr~~’hance with ES E IRXO
EvE ]RXI
instantaneous input voltage as l~#a$*M volts.
~:,{,
,,-.-,~.:,h.,+<,:?
*.<+*‘*’5::* Uuuuuuuuuuu
.$\ $..,
..... ,R\*
,,:,$$.>.“’-$<)k.,f. E2~g~ <~g;~
“*.!*,! 00><2 *
<:{.~, ,
.-p.,
‘t‘~..*\:s
,$,]? ,,
:$;,,<f:$*
,,::,
.1*.“:,.$,,,3
.~~
FIGURE 3+8%:$l&E INTERFACE BLOCK DIAGRAM
,.‘?,+.
“?~%:$>4
.,~‘,*$, .,
J’$.,,,,.~~~
~-~~+,~,J---– -–-– -––-----~Telephone
,:~., .,+ -Line Voltage Regulator
LC !:J;:t~k$~~$ 1Iv+7 Line The dc line interface circuit (Figure 3) determines the
Cl1‘xf#~siQ2 BP
$W
<~<~;::>: 1.5V
$F
dc input characteristic of the telephone. At low input
Voltage ,TI
Level Regulator ]voltages (less than 3volts) the ETC draws only the
~. IQI Shifi speech and dialer bias currents through the VR
iiVR+ regulator. As input voltage increases, QI conducts the
b*To Equalization I?C9
LR iCircuit /excess dc line current through resistor R4, The 1.5 volt
Ilevel shift prevents saturation of Q2 with telephone line
!signals up to 2,0 volts peak (+5.2 dBm). Aconstant
Icurrent (dummy load) is switched off when the DTMF
dialer is activated to reduce line current transients,
ETC ~
LFigure 4illustrates the dc voitage/current characteristic
------ ----- _____ _____ _ A~f an MC34011A telephone.
mMOTOROLA Semiconductors
GENERAL CIRCUIT DESCRIPTION (continued) pad switch transitions. When transmitting, audio signal
currents (iTXO and iRXO) flow through the voltage reg-
FIGURE 4—DC V-1 CHARACTERISTIC OF THE ETC ulator pass transistor (T1 )to drive the telephone line.
This feature has two consequences: 1)In the transmit-
<“
7.0 -ting mode the receiver sidetone current iRXO contrib-
utes to the total signal on the line along with~iTXO;
c-6“0 -
m2) The ac impedance of the telephone is deter.~,~~ by
s~ the receiver impedance and the voltage g~m~~,~’ the
:~5.Q_line to the receiver amplifier output. :.: ir’.’s$,
,~;:t
‘~,‘i,\,\
Speech Mode
z: **. ,.>;,,:”$
g~4.0 Equalization ~rcuit $’r,.,.,la*..$2.*
,1.>...~..!;,..t~,
The equalization circuit varie:,$~~t~~~’smit, receive
gm
g g 3.0 -and sidetone gains with loop c,~~~~~w’ compensate for
,0 losses in long lines. The AR ~,#inal voltage varies
,: d
A2.0 –Operable directly as the dc loop cuf~~~$ The equalization circuit
senses this voltage a,~:i$yfcfies in external resistors
~between V+ and V+,@~’5cross capacitor C6 (Figure
5) when the loopt~~&$?~xceeds athreshold level. The
10 20 30 40 50 60 120 speech network o~~~~~es with full transmit, receive and
sidetone g~#t$/~o,r long loops. On short loops the LR
Line Current (mA) ,. voltage ~@~s the threshold and these gains are
reduc&d$tT~e’t hreshold detection circuit has adc
hyste~~~is’?~prevent distortion of speech signals when
Speech Network
The speech network (Figure 5) provides the two-to- t% tel&phone is operated at the threshold current. The
four wire interface between the telephone line and the ,,.{.$q~~lization is disabled (gains at full value) during
m{;:’’qaling.
instrument’s transmitter and receiver. An electret mi- >=i.’.~:,.,:~.
crophone biased from VR drives the transmit”amplifier. &s~;~y&‘“<““’DTMF Dialer
For very loud talkers, the peak limiter circuit reduces ..\!,,, Keypad interface comparators activate the DTMF row
the transmit input level to maintain low distortion$The ~:] and column tone generators (Figure 6) when arow and
transmit amplifier output signal is inverted at tQ$+~{A column input are connected through aSPST keypad.
terminal and driven through an external R-C N~&wk~o The keypad interface is designed to function with
control the receiver sidetone level. The sw}y~,~~vac re- contact resistances up to 1.0 k~ and leakage resistances
sistance at the RM terminal reduces ~~m~$ signal as low as 150 kO. Single tones may be initiated by
when dialing and suppresses clicks d~$$~~~~k or key- depressing two keys in the same row or column.
,$j\‘~...!.’.%?
~t},:.~,>,,
*,< \’
:,y,,
,...
,* :*tiRE 5 – SPEECH NEwORK BLOCK DtAGRAM
-i
...
.
@MOTOROLA Semiconductors
3
I
i.
The programmable counters employ anovel, design
to produce non-integer frequency ratios. The various
DTMF tones are synthesized with frequency division
errors less than kO.16% (Table 1). Consequently an
inexpensive ceramic resonator can be used instead of
aquartz crystal as the DTMF frequency ‘reference. Total
frequency erro,r less than &0.8% can be achieved with
&O.3Y0 ceramic resonator. The row and column D/A
converters pr~duce 16-step approximations of sinu-
soidal waveforms. Feedback through terminal FB
reduces the DIMF output impedance to approximately
2.0 k~ to satisfi return loss specifications.
Vvl I]I,~, i
LETCJ
——— ——— ——— ———— ——— ——_
&
7’- ‘——
v-
,@ MOTOROLA Semiconductors
4
TABLE 1— FREQUENCY SYNTHESIZER ERRORS Tone Mnger
The tone ringer (Figure 7) generates awarbling
DTMF Tone Output
Standard Frequency with 1“
‘h
Deviation
(Hz) 500 kHz Oscillator from Standarc
Row 1697 696.4 –0.086
Row 2 770 769.2 –0.104
Row 3852 853.2 +0.141
Row 4941 939.8 –0.128
Column 11209 1207.7 –0.108
Column 21336 1336.9 +0.067
Column 31477 1479<3 +0.156
Column 41633 1634.0 +0.061
square wave output drive to apiezo sound element
when the ac line voltage exceeds apredetermined
threshold level. The threshold detector uses acurrent
mode comparator to prevent on/off chatter when the
output current reduces the voltage available a{ the
ringer input. When the average current into ,:~$%~e
ringer exceeds the threshold level, the ri~$~m,~tput
TRO commences driving the piezo tra$~~~#, This
output current sourced from TRI incre~:~$~e average
current measured by the threshold @#~~c~. As aresult,
hysteresis is produced beween ,&Q#~~ ringer on and
off thresholds. The output freq~~n~ at TRO alternates
between fo/8 and foil Oat a,,~~rb~~?$ateof fo/640, where
f. is the ringer oscillator~~@~ncy.
~a+,.s+.~t,,
~.>~+
PIN DESCRIPTION .,.’ ,6>
Sk>.,~$
~!.<
k. $,,,*>4‘
(See Figu;e 38 for external component identificatf$~~k>::’
,,?...
PIN PIN “.-{,,
,::$.”
~\>A,,“$:;.?$p;{i,.,
:PLCC) (DIP) Designation” Fun@~<3 ,
1-4 1-4 RI-R4 Keypad inputs for Rows 1through 4. When o~%i,t~~,~rnal 8.0 kQ resistors pull up the row inputs
to aregulated (=1.1 volt) supply. In normal’~@ratlon, arow and acolumn input are connected
through aSPST switch by the telephon@ key~w. Row inputs can also be activated by aLogic
“O” (<500 mV) from amicroprocesso#~Jtd
7-1o 5-8 CI-C4 Keypad inputs for Columns 1thr@g~#. when open, internal 8.0 kQ resistors pull down the
column inputs to V–. In norm*,,*@i~tion, connecting any column input to any row input
produces the respective row *S@jumn DTMF tones. In addition to being connected to arow
input, colu~n inputs can be acf%.dted by aLogic “1” (>600 mV and <3.0 volt).
5,6 9–1 3 NC No connection ,+* .?’+
11-15, (
!.}..
.!‘“+::$:..
23,39 ..
-?.:J\‘~~>
!,,.
16 14 ES Sidetone EquaJj2a%$~~:’*rminal connects an external resistor between the junction of R8, R9 and
V–. At loop .@;.&t#greaterthan the equalization threshold this resistor is switched in to reduce
the sideton~~~’&rThe resistor is switched out during dialing.
17 15 EV Voice ~Qtw[$~on terminal connects an external resistor between V+ and V–, for loop length
equq~~,a’~~ti~At loop currents greater than the equalization threshold this resistor is switched
i@W -e the transmit and receive gains. The resistor is switched out during dialing.
18,19 16,17 CRI, CR2 ~,:i~~~,~~ic Resonator oscillator input and feedback terminals, respectively. The DTMF dialer is
#%ended to operate with a500 kHz ceramic resonator from which row and column tones are
,,a:s<tk~):,$#nthesized.
20 18 MM .-i}:$t,$Microphone Mute. The MM pin provides ameans to mute the microphone and transmit amplifier
\.,<4
,:$, ‘~+j..
t:,.’,qj~~ in response to adigital control signal. When this pin is connected to aLogic “l” (>2.0 V) the
[k...,,*,.
,+~.‘+C.+.$: microphone dc return path and the transmit amplifier output are disabled.
21 19 ~.*;’$.&& ‘v Automatic Gain Control low-pass filter terminal. Capacitor C3 connected between AGC and VR
.*,’\\::.::.~.}. sets the attack and decay time of the transmit limiter circuit. This capacitor also aids in reducing
*\/)
~s~~....,.,*’s’
?\*. clicks in the receiver-due to hook-switch transients and DTMF on/off transients. In conjunction
‘.>:..
..,.:>>,?
,k,~,t, with i,nternal resistors, C3 (1.0 pF) forms atimer which mutes the receiver amplifier for
,.i\\+ approximately 20 milliseconds afier the user goes off-hook or releases aDTMF Key.
22$:$: $f” MIC Microphone negative supplv terminal. The dc current from the electret microphone is returned
‘s*<1:,
,.,,. to V–’through the MIC terminal which is connected to the collector of an on-chip NPN transistor.
~>~*
;“?:~.l~...
..... ~The base of this transistor is controlled either internally bv the mute signal from the DTMF
‘\$j. generator, or externally bv the logic input pin MM.
24 21 TXL Transmit Input Limiter. An internal variable resistance element at the TXL terminal controls the
transmitter input level to prevent clipping with high signal levels. Coupling capacitors C4 and
C5 prevent dc current flow through TXL. The dynamic range of the transmit peak limiter is
controlled by resistors RI 2and RI 3.
25 22 TXI Transmit amplifier Input. TXI is the input to the transmit amplifier from an electret microphone.
AC coupling capacitors allow the dc offset at TXI to be maintained approximately 0.6 Vabove
V–bv feedback through resistor RI 1from TXO.
26 23 TXO ~ransmit Amplifier Output. The transmit amplifier output drives ac current through the voltage
regulator pass-transistor TI via resistor RI 0. The dc bias voltage at TXO is typicallv 0.6 volts
)above V—. The transmit amplifier gain is controlled bv the RI l/(R12 +R13) ratio. ...!
\contlnuett)
‘@ MOTOROLA Semiconductors
5
ELECTRICAL CHARACTERISTICS (TA =25°C)
KEYPAD INTERFACE CIRCUIT
Test
Characteristic Method Svmhnl Min Tvn Max $%+
Row Input Pullup Resistance
I7IRRm I5.0 I8.0 I11 !““:~3
~th ROW Terminal: ~ = 1,2,3,4 ..:
::: ,~ts~:+l,‘.~”
, ,,,., I
Column Input Pulldown Resistance 8Rcn 5.0 8.0 $~:,;~? ;-’ ko
nth Column Terminal: n=1,2,3,4 .,1....,,
.,,<,, >::’>
Ratio of Row-to-Column Input Resistances ... .....
.,!?:r,.).3,*
7&8 Km,n 0.88 1.0 s.>.q,S*
R~, —
,,*:.?y,~,y,;h+
Km,n =m=1,2,3,4 ,,{-f . .
~..$$>,,
Rcn “?:t.~’
n=1,2,3,4 ,. :.\*y
-.i)i e:..
Row Terminal Open Circuit Voltage 7a vROC 950 1200 mVdc
Row Threshold Voltage for mth 9vRm Vdc
Row Terminal: m=1,2,3,4 —
Column Threshold Voltage for nth 10 Vcn —o
Column Terminal: n=1,2,3,4 ,. . ,,--
,,.,:$?.\\t.:t.
,, I
).30 VRnr IVdc I
ISpeech to DTMF Mode Current Differeriah) I3
.n 1.0 1.1 r1.2 volts
IDT 8.0 12 14.5 mA
@MOTOROLA Semiconductors ~
7
ELECTRICAL CHARACTERISTICS (continued)
SPEECH NEWORK
Test
Characteristic Method Symbol Min Typ Max Unit
MIC Terminal Saturation Voltage 20 VMIC —60 .125 mVdc
MIC Terminal Leakage Current 21a .,1,
IMIC —0.0 5.0 P4& .,::, ,
MM Terminal Input Resistance 21b RMM 50 100 170 %.tk~:>~ F
TXO Terminal Bias 22a ..,,
.:$;,
BTXO 0.48 0.53 0.68 .,,,>,.\*i\*’
..:,?,*
TXI Terminal Input Bias Current 22b !Txl —50 400 .8;,gp9?&*tiA
TXO Terminal Positive Swing 22C VTXO( +)—25 6&:$c+ .~;w mVdc
TXO Terminal Negative Swing 22d VTXO( -) —130 :~:28&~‘N’ mVdc
Transmit Amplifier Closed-Loop Gain 23a GTX 16.5 19 ,, ‘+,, %’ VN
Sidetone Amplifier Gain 23b GSTA 0.40 o.+~%~<,‘1$’ 054 VN
STA Terminal Output Current 24 ISTA 50 ,,,*$P’* 250 PA
RXO Terminal Bias 25a BRXO 0.48 ‘*;:4td’ 0.68 —
RXI Terminal Input Bias Current .,.
25b IRXI —~,..r<’s’’~’~,*-100 400 nA
RXO Terminal Positive Swing 25c VRXO( +)~..;iNA:\\..*.JI$
>w:*i .:?* 1.0 20 mVdc
RXO Terminal Negative Swing 25d VRXO( - ) ,+W +w,,~ 40 100 mVdc
TXL Terminal OFF Resistance 26a RTXL(OF~) ““~~>;,,125 200 300 kQ
TXL Terminal ON Resistance 26b 20 100 Q
RM Terminal OFF Resistance 27a 180 300 k~
RM Terminal ON Resistance 27b 570 770
f...,;,. Q
DTMF GENERATOR .,.
.,?
EQUALIZATl@~O’fiTROL
696.4
769.2
853.2
939.8
1207.7
1336.9
1479.3
1633.4
699.9
773.0
857.5
944.5
1213.7
1343.6
1486.7
1641.5
Hz
Hz
0.45 0.55 Vrms
0.55 0.67 vrms
1.8 3.0 dB
4.0 6.0 70
2.5 3.0 kQ
ES Termi~t*~~, Resistance 34a RES(OFF) 100 200 325 k~
.
Equali@*W$M3#reshold Voltage 34b VE 1.4 1.6 2,0 Vdc
Eqpa~~ff&A Threshold Hysteresis 34C AVE 75 200 300
E*i:~~~lnal OFF Resistance
mVdc
,’~.’$,..~~. 35a RFV(OFF) 100 200 325 kQ
EV ferminal ON Resistance 35b REv(ON) —20 50 Q
@MOTOROLA Semiconductors
8
ELECTRICAL CHARACTERISTICS (continued)
TONE RINGER
Test
Characteristic Method Symbol Min Typ Max Unit
TRI Terminal Voltage 14 VTRI 20 21.5 23 yc
TRS Terminal Input Current ITRS ~.j:{,y,...<:~;:,.
,,>~~~,,
VTRS =24 volts 15a 70 ,;’:$’,%~.,
120 170 s ::’’:$PA
VTRS =30 volts 15b ... !“,
0.4 0.8 1.5,1,’.J..i,:::+~”mA
TRF Threshold Voltage 16a VTRF 1.2 1.6 ,::.l’!b:~)““ Vdc
TRF Threshold Hysteresis 16b AVTRF 100 200 ,,,>~~~p’”” mVdc
TRF Filter Resistance 17 RTRF 30 50 .?,
.$!;, ;+ ‘$5 k~
High Tone Frequency 18 fH 920 I@@i “Q’ 1080 Hz
Low Tone Frequency 18 fL 736 ,..,i:ar 864 Hz
Warble Frequency 18 fw 11.5 :{“q$”Jp.5 13.5 Hz
Tone Ringer Output Voltage “.,.,.,. \ J..,,.,.,
19 VO(P-P) 18 ,~~ .:f~ 20 22 Vp-p
.,,>/Y,.. ~
N.
20
0MIC
v- 30 L
VR 29 7
28
CAL 270 *
RXO ,
26 ~100 k
RXI 2.0 k510
25
RM o
STA [24 o
Notes: .~ &
1. *Selected ceramic resonator: 500 kHz f2.o kHz.
2. Capacitances in pF unless noted.
3. All resistances in ohms.
4. Rn numbers in this Rgure and in Test Circuits are for the DIP package.
~“ @MOTOROLA Semiconductors
-.
9.
a.
b.
c.
I
FIGURE 9—TEST ONE
-
General
Test
Circuit
I
29 ~vR
Measure VR with VS =1.7 V
Measure Isp with VS =1.7 V
Measure Isp with VS =5.0 V
l.v.~.
W~ S1 open measure ITR. Close S1 and again measure
ITR. Calculate:
AITR =ITR -ITR
SI SI
Closed Open
FIGURE 10 —TEST WO
General
Test
Circuit
=11.5V
=26 V. Calculate
a.
b.
FIGURE 12 —TEST FOUR
General
Test
Circuit
—
Set VS =5.0 Vand ILR =10 mA. Measure V[R,
Calculate AVLR =Vs -Vi-R
Repeat Test 4a with Vs =18 Vand ILR =110 mA
—
‘@MOTOROLA ‘Semiconductors
10
FIGURE 13 —TEST FIVE
General
Test
Circuit P
34
SI +5.0 v
31 I
ILC Y
vLC
VVith S1 open measure VLC.
Close S1 and measure ILC.
Calculate:
5.0 –vLC
RLC =ILC .
.,.,,,,(, I
T5,0 V
—
FIGURE 14 —TEST SIX
General
Test
Circuit
FIGURE 16 —TEST EIGHT
L
General
Test
Circuit
Subscript ncorresponds to column number.
a. Set S1 to Terminal 5(n =1) and measure Icl. Calculate:
Rcl =1.OV +ICI
b,c,d. Repeat Test 8a for n=2,3,4.
FIGURE 17 —TEST NINE FIGURE 18 —TEST TEN
34
Sq 34
SI 29
VI General &I5.0 vGeneral
Test —Test
.
—Circuit VI 7-Circuit
—
—
VMIC
o20
wo20
vMlc
10 k ,
mcorresponds to row number.
,+$y$ y:
‘\”‘ .,..>*...
,~.,+..,..,>,.,<
..*&&:t~,:.,,
a. Set S1 to Terminal 1(m =1) with VI =1.0 Vdc. Verify ,,..
a. Set Sl=+~$~er@iriai 5(n =1) with VI =OVdc. Verify
VMIC is LOW (VMIC <0.3 Vdc). Decrease VI to 0,70 VROC VMl~~$@~~MIC <0.3 Vdc), Increase VI to 0.30 VROC
and verify VMiC switches high. (VMIC >0.5 Vdc). VROC a~~dvefl~ VMIC switches high, (VMIC >0.5 Vdc). VROC
is obtained from Test 7a. Wwtained from Test 7a;
b,c,d. Repeat Test 9a for rows 2,3, and 4. (m =2,3,4) +$c~k ‘#epeat Test 10a for columns 2,3, and 4. (n =2,3,4)
‘*?*~+...!’
‘!$>):.*.,,,:,!.~
.~J:..>:L5:,8*,
..,, ....*.y.
“<i
*,
,~i{+ *i~
.,sy,,
FIGU~’ l%.- TEST ELEVEN
*V,,>~.,,.,
*‘*&:: ‘~:$~
,,$$:
,{*>
34
*;
*3a. With VI =0.0 Vset S1 to Terminal 1(m =1) and
SI *4meaaure frequency of tone at V+.
*5General ,,y$$,q$ _b. Repeat Test 11. “or rows 2,3 and 4. (m =2,3,4).
b6Teat fp’” at?‘~+ c. With V1 =1.0 Vset S1 to Terminal 5. (n =1) and
.‘~.:.,..;;
6 7 Cir@~J,*y ,~
8measure frequency of tone at V+.
“,,$:
“!~~.., :<.;
>,:,$$$>, d. Repeat Test for columns 2,3, and 4. (n =2,3,4).
—,.:!~.>:’
.~{i.:,
*<*S e. Set S1 to Terminal 4and V1 =0.0 V. Measure row tone
,,!,.~’‘+$:,>.,?*
,:$kl?~,J“*
i$it:~l..$, amplitude at V+ (VROW).
*,\i,
,,*X~,.j,,/,. f. Set S1 to Terminal 8and V! =1.0 V. Measure column
tiik,i,’r*..
>.>+, tone amplitude at V+. (VCOL).
$:\i,LF+t‘~s*\
,$.*.:\~-.,.J&)
+x ~g. Using results of Teats 1Ie and 1If, calculate:
,$. ‘%.;,?
...... ,
.*?.*\?$,.~*,,$s. VCOL
..~,,,<!<.
>::,!
,.rs~sm corresponds to row number, dBCR =20 Ioglo —
.\/+
.,,., “~~.% VROW
,,$..<F..Y:8,,,\,ncorresponds to column number.
.>,,,,,,,
.$$,
~?
mMOTOROLA -Cimiinnd,..tn..
u‘--– -‘- -;2–” -‘---”=---=-u”--=”
FIGURE 20 —TEST WELVE FIGURE 21 —TEST THIRTEEN
m
4
5
+’
1
General
I.ov Test
—— Circuit
600 Q
General
Test
Circuit
34
K
+
v+ I15V
940 Hz ~
Notch Filter
1209 Hz
Notch Filter
VI
1~-i
5
+
I.ov
1
——
-_
L1’
10 kHz Single
Pole LPF
Note: The notch filters must have 50 dB attenuation at their
respective center frequencies.
Measure V+ and V1 with atrue rms voltmeter. Calculate:
V1 (rms)
‘/o DIS =—X loo
V+(rms)
FIGURE 23 —TEST Fl~EEN
38
37 ITRS
11
Vlk i20v
— —
General
Test
Circuit
a. Measure ITRS with VI =24 V.
b. Measure ITRS with VI =30 V.
@MO~OROLA Semiconductors
13
FIGURE 27 —TEST NINETEEN FIGURE 28 —TEST TWENTY
I
—39 QVTRO
38
37 _
General
Test
— —
I34
General
Test
Circuit
18
Circuit
I10.8
Measure VTRO peak-to-peak voltage swing.
Using VTRl from Test 14 Calculate:
Vo(p.p) =VTRI – 20 V+VTRO
FIGURE 30 —TEST TWENTY-TWO
a.
b.
c.
d.
34
General
Test
Circuit
With S1 open, measure VTxO. Using VR obtained in Test
1Calculate: BTxO =VTxO +VR
With S1 open, measure VTxO and VTxI. Calculate:
lTx[ =(VTxO –VTxl) +200 k~
Close S1 and set I=– 10 PA. Measure VTXO. Calculate:
VTxO( +)=VR –VTxO where VR is obtained from
Test 1.
Close S1 and set I=+10 @. Measure VTXO.
VTXO( –)=VTXO.
=2.O Vand measure IMIC.a. Set VI
b. Set VI.= 5.0 Vand measure IMM,
Calculate: RMM =5.0 V+IMM
I
I
I
I
~@ MOTOROLA Semiconductors
15
FIGURE 35 —TEST TWENTY-SEVEN
General
Test
Circuit
34
I5.0 v
..
I
VRM 10k~
.L%T
—2.0 KF
$
1,0 vrm~ -Vi
1.0 kHz
a. With S2 open and S1 in position 1
Ameasure IRM. ——
Calculate: RRM(OFF)=O.4 V+IRM
b. Close S2 and switch Sq to position B. Measure ac
voltages vi and VRM.
Calculate:
RRM(ON) =VRM
Vi –VRM xlokfl .t
,L
.,.’. “~
,.\\.
Test 34b ~~st 34C
Note: Tests 28-33 intentionally
omitted.
FIGURE 37 —TEST THIRTY-FIVE
34
+
General
Test
iEv ACircuit =
+
V1
1.0 kHz ~I
a. With S1 in position Aset V1 =2.0 V. Measure IEV Calcu-
late REV(OFF) =0.4 +IEV.
b. Set V1 =5.0 Vand Set S1 to position B. Measure vi and
VEv, calCU\ate
REV(ON) =VEv X600 ~
Vi –vEV
—
,.
APPLICATIONS INFORMATION
Figure 38 specifies atypical application circuit for the
MC3401 1A. Complete listings of external components
are provided at the end of this section along with
nominal component values.
The hook switch and polarity guard bridge
configuration is one of several options. If two bridges
are used, one for the tone ringer and the other for
speech and dialer circuits, then the hook switch can be
simplified. Component values should be varied to
optimize telephone performance parameters for each
application. The relationships between the application
circuit components and certain telephone parameters
are briefly described in the following:
On-Hook Input Impedance
Rl, C17, and 23 are the significant components for
on-hook impedance. C17 dominates at low frequencies,
RI at high frequencies and 23 provides the non-linearity
required for 2.5 Vand 10 Vimpedance signature tests.
C17 must generally be s1.0 pF to satisfy 5.0 Hz
impedance specifications. (EIA RS-470)
Tone Ringer Out~ut Frequencies
,,,
receiver amplifier decreases the impedance of the
telephone.
DTMF Output Amplitude
R14 controls the amplitude of the row and cQ{~&,
DTMF tones. Decreasing RI 4increases the level,@$J~$@s
generated at V+. The ratio of the row and cq%~,$~$one
amplitudes is internally fixed. R14 shoW,Q@~,greater
than 200 to avoid excessive current in k@$@~@Foutput
amplifier.
Transmit Output Level ~, ~s;tk+l}
RIO controls the max,i~#& signal amplitude
produced at V+ by the ~~w.~~~amplifier. Decreasing
RIO increases the transtij~<~u~put signal at V+. RIO
should be greater ~x~~~~ Qto limit current in the
transmit amplifie~~oukhy~
The ga~s $~w@the microphone to the telephone line
varies diwly’ with RI 1. Increasing RI 1increases the
sig~~~,appW&dto RIO and the ac current driven through
RJQ,t@$$he telephone line. The closed loop-gain from
R3 and-C13 co;trol the”frequency (fo) of arelaxation .~e ‘@microphoneto the TXO terminal should be greater
oscillator. Typically f. =(R3C13 +8.0 Ps)-l. The ,..,~~$@*ti”lOto prevent transmit amplifier oscillations.
~i,~$:,r-.$,,r,t.>
output tone frequencies are fo/l Oand fo/8. The warble ‘*~;.Note: Adjustments to transmit level and gain are
rate is fo/640. The tone ringer will operate with f. from $> complicated by the addition of receiver sidetone
1.0 kHz to 10 kHz. R3 should be limited to valW&,
.. ‘::,;,,~
,X:j.t.” .,
Tone Ringer Input Threshold ..},..$.,$’’”.,~’
,:$,.+.?,3,,,,,J~
After RI, C17, and 23 are chosen to s.$~~~%,$ti-hook
impedance specifications, R2 is chosemi$QR’@{ desired
ring start threshold. Increasing R2 (e~~$$$ the ac input
voltage required to activate the t~-e qnger output. R2
should be limited to values b~@,~@@.8 kand 2.0 k~.
&j,*, ,:~.
Off-Hook DC Resistance ,~y$~:,,~~~
R4 conducts the dc line c&x[,@t in excess of the speech
and dialer bias cur~$~,~ Increasing R4 increases the
input resistance of t~+’~~.~+phone for line currents above
IomA. R4 shou~~~~elected between 30 Qand 120 Q.
+::.et}
.’,:~.~,+,,‘.,~~,
Off-Hook ~:t~qpbdance
The aq~ain$u~ impedance is equal to the receive
ampl&W@#,’’i~b~dimpedance (at ,RXO) divided by the
re~eiv~$~rnplifier gain (voltage gain from V+ to RXO).
ln~~~lng the impedance of the receiver increases the
imp~dance of the telephone. Increasing the gain of the
current to the transmit amplifier output current
at V+. Normally the sidetone current from the
receiver will increase the transmit signal (if the
curre~t in the receiver is in phase with that in
RIO), Thus the transmit gain and sidetone levels
cannot be adjusted independently.
Receiver Gain
Feedback’ resistor R6 adjusts the gain at the receiver
amplifier. Increasing R6 increases the receiver amplifier
gain.
Sidetone Level
Sidetone reduction is achieved by the cancellation of
receiver amplifier input signals from R9 and R5. R8, RI 5,
and C6 determine the phase of the sidetone balance
signal in R9. The ac voltage at the junction of R8 and
R9 should be 180” out of phase with the voltage at V+.
R9 is selected such that the signal current in R9 is
slightly greater than that in R5. This insures that the
sidetone current in the receiver adds to the transmit
amplifier output current.
.
@MOTOROLA Semiconductors ~
18
Equalization of Speech Network
Resistors R17 and R18 are switched into the circuit Thus resistor R4 is selected to activate the
when the voltage at the LR terminal exceeds the equalization circuit at the desired loop current.
equalization threshold voltage (typically 1.65 V). R17 However, R4 must be selected keeping in mind the fact
reduces the transmit and receive gains for loop currents that it also controls the dc resistance of the telephone.
greater than the threshold (short loops) by attenuating Capacitors Cl 8and Cl 9prevent dc current flo~.~h~~ the
signals at tip and ring. R18 reduces the sidetone level EV and ES terminals. This reduces clic~,$:r’~$~~%lso
which would otherwise increase when R17 is switched prevents changes in the dc characteF~st~#iof the
into the circuit. The voltage VLR at LR terminal is given **,,..7J,.,.J*.
telephone when the EV and ES termiRs4~Rf& switched
by
VLR =(4L –4s) xR4.
where IL =loop current
Is =dummy load current (6.0 mA) +speech ..\\t.+~,;,~..
,1, ,,:>>J,
nnti~jnrb e,,rrant 1A n m Al .’..:,
.5?.$.~,.,
to low impedance.
FIGURE 38 —ELECTRONIC TELEPHONE
a
o# 4R4
5cl
JIT
[
1
DTMF Pad 1~40 ‘@’’=ndE’ement . .
Row-Column Switch Closure 4
7
*
$?~y..\::,$,.:?,
rD
71 ~-’+ *
‘L ,, .(:J. .. 9A _
Nc -
S1, S2 controlled
bv hook switch; Illustrated &
in “on-hooK’
condition.
<\.
>D
Receiver
300 n
I I
F
TIP
4
S1 R1
R5 C17
B1
16
L-CRI ;;: 125 !
23 na KIO
TXO -2LC6 RING
RX*
4Electret
. ... . .. )ne
I/1+ I*RX used with
2-terminal mike onlv.
III
@MOTOROLA Semiconductors
19
EXTERNAL COMPONENTS
(Component Labels Referenced to Figure 38)
Capacitors
cl, C2
C3
C4, C5
C6
C7, C8
C9
cl o
cl 1
cl 2
C13
C14
C15
C16
C17
C18
C19
R12, R13
R14
R15
RI 7
R18
RX
Nominal
Value
100 pF
1.0 pF, 3.0 V
0.1 PF
0.05 pF
0.05 AF
2.2 pF, 3.0 V
0.01 pF
0.1 pF
0.01 pF
620 pF
0.1 pF
4.7 pF, 25 V
1.OKF,1OV
1.0 pF, 250 Vac
Non-polarized
25 p~ 25 V
5.0 WE 3.0 v
Nominal
Value
4.7 k, 4.7 k
36
2.0 k
600
5.1 k
3.0 k
Description
Ceramic Resonator oscillator capacitors. *,\
Transmit limiter low-pass filter capacitor controls attack and decay time of transmit peak IiWt. *’X,l,
:. “’”
Transmit amplifier input capacitors: prevent dc current flow into TXL pin and aftenuat~’~~k~uency
noise on microphone lead. h,,*:,.e&,,,,,:~
,,:,<.,,
~,\\.,,,,~i,
Sidetone network capacitoc provides phase-shift in sidetone path to match that~txd’by telephone
.,~., \~,:
line reactance. *X$7
.’,:’7,.~::$,.
%~:~~j,,,<t.~’t$,.
Receiver amplifier input capacitors: prevent dc current flow into RM termina~%,swuates low frequency
noise on the telephone line. ~l+~.li,;,:
‘‘.,>:.,
VR regulator capacitor: frequency compensates the VR regulator {$$~ven~oscillation.
~.?..!,
.,,,,>.
Receiver amplifier output capacitor: freq}ency compensates th$.$~~~~amplifier to prevent oscillation.
DC load filter capacitor: prevents the dc load circuit from aQ#~@!~<ac signals on V+,
+:/:,,,‘i.~:..<:,~
Telephone line bypass capacitor: terminates telephone~@,.~r' tiighfrequencys ignalsand PreVentS
oscillation in the VR regulator, ~i.<.
.>, ,.<
.~~+./,,
;:$:-,
Tone ringer oscillator capacitor: determines clock fr~- for tone and warble frequency synthesizers.
~~’itt!.\?i~,.
DTMF output feedback capacitor: ac couples f~bb~k%round the DTMF output amplifier which reduces
output impedance. ‘~~“l:\t{,\,h.+.’
.?.
,.~,/!\r
*,.!.\
Tone ringer input capa~tor: filters the$ectl@ tone ringer input signal to smooth the supply potential
foroscillator and output buffer. .
~:,*’ii;:?,,
Tone ringer filter capacitor: inte~$~~:the voltage from current sense resistor R2at the input of the
threshold detector. $$. ...
i?.~:.,,
~?.!,.,:r.:$
~~,,:d,,<:;,.*.,.
Tone ringer line capacitor a~,i~~les thetone ringer to the telephone line; partially controls the on-
hook input impedance of te~epbne.
Speech equalizati~~~oup~ng capacitor. Prevents dc current flow into EV terminal. (optional)
Sidetone equal~z~~n ‘~upling capacitor. Prevents dc current flow into ES terminal. (optional)
.,.*.s:,p\\:\:$.
.>,.~k.. :. .+~~
*,,.:,,<,, ~$<\*t.: Description
~pri~~$~r input resistor limits current into the tone ringer from transients on the telephone line and
.P#~@~ controls the on-hook impedance of the telephon~.
~T@e ringer current sense resistor: produces avoltage at the input of the threshold detector in proportion
to the tone ringer input current.
Tone ringer oscillator resistor: determines the clock frequency for tone and warble frequency synthesizers.
DC load resistor: conducts all dc line current in excess of the current required forspeech or dialing
circuits; controls the off-hook dc resistance of the telephone.
Receiver amplifier input resistors: couple ac input signals from the telephone line to the receiver amplifier;
signal in R5 subtracts from that in R9to reduce sidetone in receiver.
Receiver amplifier feedback resistoc controls the gain of the receiver amplifier.
Sidetone network resistors: drive receiver amplifier input with the inverted output signal from the trans-
mitter; phase of signal in R9should beopposite that in R5.
Transmit amplifier load resistor: converts output voltage of transmit amplifier into acurrent that drives
the telephone line; controls the maximum transmit level,
Transmit amplifier feedback resistor: controls the gain of the transmit amplifier.
Transmit amplifier input resistors: couple signal from microphone to transmit amplifier; control the dynamic
range of the transmit peak limiter.
DTMF calibration resistor: controls the output amplitude of the DTMF dialer.
Sidetone network resistor (optional): reduces phase shift in sidetone network at high frequencies.
Speech equalization resistor. Reduces transmit and receive gain when EV terminal switches on. (optional)
Sidetone equalization resistor. Reduces sidetone level when ES terminal switches on. (optional)
Microphone bias resistor: sources current from VR to power a2-terminal electret microphone; RX is not
used with 3-terminal microphones.
,1
‘@MOrOROLA Semiconductors
EXTERNAL COMPONENTS (continue
Semiconductors
BI =MDAIOIA, or equivalent,
or 4-1 N4005
TI =2N4126 or equivalent
21 =18 V, 1.5 W, IN5931A
22 =30 V, 1.5 W, IN5936A
23 =4.7 V, 112W, 1N750
XR —muRata Erie CSB 500 kHz
Resonator, or equivalent
Piezo —PBL 5030BC Toko Buzzer
or equivalent
Motorola Inc. does not endorse or wa
)Eletiret Mic Receiver
2Terminal, Primo EM-95 (Use Rx) Primo Model DH-34 (300 Q) or equivalent
or equivalent
3Terminal, Primo 07A181P (Remove Rx)
or equivalent
>,,,,L.!a
,*
$>..
~i};,:t,’:~’iJ&%a\.
,t<..$,.>
,x,,,~~}...h,
1,.:,,,<
....?s:.
II‘>%8..:>$
ant the suppliers referenced. *T ,,,;,.
‘.:t~:,.1*
Qk$‘~
\Ai:~.:f~‘t\y\.
,,@
‘~t$>,.
y,
‘i>i$><j,y
..;.
OUTLINE DIMENSION
NOTES
1. DIMENSIONSRAND UDO NOT INCLUDEMOLD
FLASH.
I“B.i 2. DIMENSIONINGAND TOLERANCINGPERANSI
Y14.5M. 1982.
la
—K3. CONTROLLINGDIMENSION: INCH
.-
#-i
-. :+F~
H- i
-J
,IE ‘o
-c
44-PIN
PLCC
CASE 777-01
Motorola resewes the right to make changes without tiflher notice to anv products herein to improve reliatili~, funct)on or des,gn. Motorola does not assume anv Iiabditv
arising out of the application or u= of anv produti or circuit descri~ herein; neither does It convey any l#censeunder its patent rights nor the rights of others. Motorola and ,
@are registered t,adema,ksofMotorola, 1“.,
.@ MOTOROLA Semiconductors
21
mMOTOROLA Semiconducteurs S,A.
AVENUE GgN~RAL EISENHOWER, 31023TOULOUSE CEDEX, FRANCE —
22 Pdntd in Grm SMn ~Stale bJwi~s 2W 7~7