SPEECH NETWORK WITH DIALER INTERFACE
S1T2425A
1
INTRODUCTION
The S1T2425A is telephone speech network integrated circuit which
includes transmit amp, receive amp, side tone amp, DC loop interface
function, DTMF input, voltage regulator for speech, a regulated output
voltage for a dialer, and equalization circuit .
FEATURES
Low voltage operation (1.5V : speech)
Transmit, Receive, Side tone and DTMF level
are controlled by external resistors
Regulated voltage for dialer
Loop length equalization
MUTE function
Linear interface for DTMF
ORDERING INFORMATION
PIN CONFIGURATION
Device
Package
Operating Temperature
S1T2425A01-D0B0
18
-
DIP
-
300A
-
20 to + 60
C
18
-
DIP
-
300A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
S1T2425A
MIC
TXI
TXO
STA
CC
EQ
RXI
RXO
RMT
MT
MS
TI
V
DD
V+
LR
LC
VR
V-
S1T2425A
SPEECH NETWORK WITH DIALER INTERFACE
2
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED OPERATING CONDITIONS (TA = 25
C)
Characteristic
Symbol
Value
Unit
V
+
Voltage
V
C
-
1.0 to +18
V
V
DD
(V
+
= 0)
V
DD
-
1.0 to +6
V
MT,MS inputs
V
M
-
1.0 to V
DD
+1
V
V
LR
V
LR
-
1.0V to V
+
-3.0
V
Storage Temperature
T
STG
-
65 to +150
C
Characteristic
Symbol
Value
Unit
I
TXO
(Instantaneous)
I
CC
0 to 10
mA
V
+
(Voltage :Speech Mode
V
+ (SM)
+1.5 to +15
V
Tone Dialing Mode
V
+(TM)
+3.3 to +15
V
Operating Temperature
T
ORR
-
20 to +60
C
ELECTRICAL CHARACTERISTICS (T
a
= 25
C)
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
SYSTEM SPECTIFICATIONS (Refer to Fig.3 and Fig.4)
TX Gain from V
S
to V
+
Gain Change
Distortion
Output Noise
G
V (TX)
G
V (TX)
THD
TX
V
NO (TX)
Figure (I
L
= 20mA)
I
L
= 60mA
28
-
6.0
-
-
29.5
-
4.5
2.0
11
31
-
3.6
-
-
dB
dB
%
dBmc
RX
V
RXO
/ V
S
RX Gain Change
Distortion
G
V (RX)
G
V (RX)
THD
RX
f = 1.0kH
Z
, I
L
= 20mA
(See Figure.4)
I
L
= 60mA
-
16
-
5.0
-
-
15
-
3.0
2.0
-
13
-
2.0
-
dB
dB
%
DTMF Driver V
+
/ V
IN
G
V (MF)
I
L
= 20mA
3.2
4.8
6.2
dB
Sidetone Level V
RXO
/ V+
G
V (ST)
I
L
= 20mA
I
L
= 60mA
-
-
-
28
-
13
-
-
dB
Sidetone rejection
RST
I
L
= 20mA
12
18
-
dB
{ (figure 4)} dB
-
{ (figure 3)}dB
V+
V
RXO
V+
V
RXO
SPEECH NETWORK WITH DIALER INTERFACE
S1T2425A
3
Tip-Ring Voltage
(including polarity guard bridge
drop of 1.4V)
(Speech Mode)
V
TR
I
L
= 5.0mA
I
L
= 10mA
I
L
= 20mA
I
L
= 40mA
I
L
= 60mA
-
-
-
-
-
2.4
3.9
4.6
5.6
6.6
-
-
-
-
-
V
DC
AC impedance
Speech mode (incl. C
6
,see fig.
4)
Z
ac
= (600)V +/ (V
S
- V+)
Tone Mode (including C
6
)
Z
ac
I
L
= 20mA
I
L
= 60mA
20mA < IL , 60mA
-
-
-
750
300
1650
-
-
-
W
SYSTEM AMPLIFIERS
TX Gain
TXO Bias Voltage
TXO Bias Voltage
TXO Bias Voltage
TXO Bias Voltage
TXI input Resistance
G
V (TX)
V
BIAS (SPM)
V
BIAS (TM)
V
OL (SPM)
V
OL (SPM)
R
I (TXI)
TXI to TXO
Speech/Pulse Mode
Tone Mode
Speech/Pulse Mode
Speech/Pulse Mode
24
0.45
V
R
-
25
V
R
-
25
-
-
26
0.52
V
R
-
5.0
V
R
-
5.0
125
10
28
0.60
-
-
250
-
dB
xV
R
mV
mV
mV
k
RX
RXO Bias voltage
RXO Source current
RXO Source current
RXO High Voltage
RXO Low Voltage
V
BIAS (AM)
I
SOURCE (SM)
I
SOURCE (PTM)
V
OH (AM)
V
OL (AM)
All Mode
Speech Mode
Pulse/tone Mode
All Mode
All Mode
0.45
1.5
200
V
R
-
100
-
0.52
2.0
400
V
R
-
50
50
0.60
-
-
-
150
xV
R
mA
A
mV
mV
SIDETONE AMPLIFIER
Gain (TXO to STA)
Speech Mode
Speech Mode
Pulse Mode
Pulse Mode
Gv
(STA)
@V
LR
= 0.5V
@V
LR
= 2.5V
@V
LR
= 0.2V
@V
LR
= 1.0V
-
-
-
-
-
15
-
21
-
15
-
21
-
-
-
-
dB
STA Bias Voltage
V
BIAS (STA)
All Modes
0.65
0.8
0.9
xV
R
MICROPHONE, RECEIVER CONTROLS
MIC Saturation Voltage
V
SAT (MIC)
Speech Mode,1 = 500
A
-
50
125
mV
MIC Leakage Current
I
LKG (MIC)
Dialing Mode,Pin 1=3.0V
-
0
5.0
A
MAT Resistance
R
RMT (SM)
R
RMT (DM)
Speech Mode
Dialing Mode
-
5.0
8.0
10
15
18
k
RMT Delay
t
D (RMT)
Dialing to Speech
2.0
4.0
20
ms
EQUALIZATION AMPLIFIER
GAIN (V + to EQ)
Speech Mode
Speech Mode
Pulse Mode
Pulse Mode
G
V (EQ)
@ V
LR
= 0.5V
@ V
LR
= 2.5V
@ V
LR
= 0.2V
@ V
LR
= 1.0V
-
-
-
-
-
12
-
2.5
-
12
-
2.5
-
-
-
-
dB
ELECTRICAL CHARACTERISTICS (T
a
= 25
C) (Continued)
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
S1T2425A
SPEECH NETWORK WITH DIALER INTERFACE
4
NOTE: Typicals are tested or guaranteed.
EQ Bias Voltage
Speech Mode
Pulse Mode
Speech, Pulse Mode
V
BIAS (EQ)
@ V
LR
= 0.5V
@ V
LR
= 0.5V
@ V
LR
= 2.5V
-
-
-
0.66
1.3
3.3
-
-
-
V
dc
DIALING INTERFACE
MT Input Resistance
R
1 (MT)
-
50
100
-
k
MT Input High Voltage
V
IH (MT)
-
V
DD
-0.3
-
-
V
dc
MT Input Low Voltage
V
IL (MT)
-
-
-
1.0
V
dc
MS Input Resistance
R
I (MS)
-
280
600
-
k
MS Input High Voltage
V
IH (MS)
-
2.0
-
-
V
dc
MS Input Low Voltage
TI Input Resistance
V
IL MS)
R
I (T1)
-
-
-
-
-
1.25
0.3
-
V
dc
k
DTMF Gain
G
V (MF)
-
3.2
4.8
6.2
dB
LINE INTERFACE
V+ Current (Pin 12 Grounded)
Speech Mode
Speech/Pulse Modes
Tone Mode
1+
V+ = 1.7V
V+ = 12V
V+ = 12V
4.5
5.5
6.0
7.1
8.4
8.8
9.0
12.5
14.0
mA
V+ Voltage
Speech/Pulse Mode
Speech/Pulse Mode
Speech/Pulse Mode
Tone Mode
Tone Mode
V+
I
L
= 20mA
I
L
= 30mA
I
L
= 120mA
I
L
= 20mA
I
L
= 30mA
2.6
3.0
7.0
4.1
4.5
3.2
3.7
8.2
4.9
6.4
3.8
4.4
9.5
5.7
6.2
V
dc
LR Level Shift
Speech/Pulse Mode
Tone Mode
V
LR
V + -V
LR
-
-
2.7
4.3
-
-
V
dc
LC Terminal Resistance
R
LC
-
36
57
94
K
VOLTAGE REGULATORS
VR Voltage
Load Regulation
Line Regulation
V
R
V
O
V
O
(V+ = 1.7V)
0mA < I
R
< 1.6mA
2.0V < V + < 6.5V
1.1
-
-
1.2
20
25
1.3
-
-
V
dc
mV
mV
V
DD
Voltage
Load Regulation (Dialing Mode)
Line Regulation (All Modes)
Max. Output Current
Max. Output Current
V
DD
V
O (DM)
V
O (AM)
I
OSM (MAX)
I
ODM (MAX)
(V+ = 4.5V)
0 < I
DD
< 1.6mA
4.0V < V + < 9.0V
Speech Mode
Dialing Mode
3.0
-
-
375
1.6
3.3
0.25
50
550
2.0
3.8
-
-
1000
3.6
V
dd
V
dd
mV
A
mA
V
DD
Current Leakage
I
LKG (VDD)
V + = 0, V
DD
= 3.0V
-
-
1.5
A
ELECTRICAL CHARACTERISTICS (T
a
= 25
C) (Continued)
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Unit
SPEECH NETWORK WITH DIALER INTERFACE
S1T2425A
5
TEST CIRCUIT
Figure 1. DTMF Driver Test
Figure 2. Transmit and sidetone level test
16
14
13
12
18
17
10
KA2425A
V+
22K
V
IN
400mVrms
1.0V
204
47
600
20
F
+
I
LOOP
S1T2425A
2
4
7
8
14
15
17
KA2425A
150
20
F
6
3
11
18
13
12
10
+
V+
150K
8.2K
503
33K
10K
20mVrms
1KHz
Vs
Microphone Equivalent
I
LOOP
600
203
47
10
204
150
503
S1T2425A
S1T2425A
SPEECH NETWORK WITH DIALER INTERFACE
6
Figure 3. Impedance, Receive and Sidetone Rejection Test
2
4
7
8
14
15
17
KA2425A
6
3
11
18
13
12
10
V+
150K
8.2K
503
33K
47
10
204
150
503
+
20
F
I
LOOP
203
20mVrms
1KHz
Vs
S1T2425A
SPEECH NETWORK WITH DIALER INTERFACE
S1T2425A
7
APPLICATION CIRCUIT
6
14
4
15
13
12
11
10
1
2
3
7
8
9
KA2425A
33
F
68
, 1/2
TIP
RING
H/S SW
-
+
103
220K
8.2K
4.7K
3.3K
+
393
102
383
383
22
F
+
120K
472
47
F
+
SPEAKER
200
2.2K
223
102
MIC
S1T2425A
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