Page 1
SPEECH NETWORK WITH DIALER INTERFACE S1T2425A
INTRODUCTION
18− DIP− 300A
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
Device Package Operating Temperature
S1T2425A01-D0B0 18− DIP− 300A − 20 to + 60° C
PIN CONFIGURATION
MIC
1
TXI
2
TXO
3
STA
4
CC
EQ
RXI
5
6
7
S1T2425A
18
17
16
15
14
13
12
MT
MS
TI
V
V+
LR
LC
DD
RXO
RMT
8
9
11
10
VR
V-
1
Page 2
S1T2425A SPEECH NETWORK WITH DIALER INTERFACE
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Value Unit
V+ Voltage V
VDD (V+ = 0) V
MT,MS inputs V
V
LR
Storage Temperature T
V
C
DD
M
LR
STG
RECOMMENDED OPERATING CONDITIONS (TA = 25°C)
Characteristic Symbol Value Unit
I
(Instantaneous) I
TXO
V+ (Voltage :Speech Mode V
Tone Dialing Mode V
Operating Temperature T
CC
+ (SM)
+(TM)
ORR
ELECTRICAL CHARACTERISTICS (Ta = 25°C)
Characteristic Symbol Test Conditions Min. Typ. Max. Unit
−1.0 to +18 V
−1.0 to +6 V
−1.0 to V DD +1 V
−1.0V to V + -3.0 V
−65 to +150 °C
0 to 10 mA
+1.5 to +15 V
+3.3 to +15 V
− 20 to +60 ° C
SYSTEM SPECTIFICATIONS (Refer to Fig.3 and Fig.4)
TX Gain from VS to V
Gain Change
Distortion
Output Noise
+
G
V (TX)
∆ G
V (TX)
THD
V
NO (TX)
TX
Figure (IL = 20mA)
IL = 60mA
RX
V
/ V
RXO
S
RX Gain Change
Distortion
DTMF Driver V+ / V
Sidetone Level V
RXO
IN
/ V+ G
G
V (RX)
∆ G
THD
G
V (MF)
V (ST)
V (RX)
RX
f = 1.0kHZ, IL = 20mA
(See Figure.4)
IL = 60mA
IL = 20mA 3.2 4.8 6.2 dB
IL = 20mA
IL = 60mA
Sidetone rejection
V
RXO
{ (figure 4)} dB
RST IL = 20mA 12 18 − dB
V+
V
RXO
− { (figure 3)}dB
28
−6.0
−
−
−16
−5.0
−
−
−
29.5
− 4.5
2.0
11
−15
−3.0
2.0
−28
−13
31
−3.6
−
−
−13
−2.0
−
−
−
dB
dB
%
dBmc
dB
dB
%
dB
2
Page 3
SPEECH NETWORK WITH DIALER INTERFACE S1T2425A
ELECTRICAL CHARACTERISTICS (Ta = 25°C) (Continued)
Characteristic Symbol Test Conditions Min. Typ. Max. Unit
Tip-Ring Voltage
(including polarity guard bridge
drop of 1.4V)
(Speech Mode)
AC impedance
Speech mode (incl. C6,see fig.
4)
Zac = (600)V +/ (VS - V+)
Tone Mode (including C6)
SYSTEM AMPLIFIERS
TX Gain
TXO Bias Voltage
TXO Bias Voltage
TXO Bias Voltage
TXO Bias Voltage
TXI input Resistance
RX
RXO Bias voltage
RXO Source current
RXO Source current
RXO High Voltage
RXO Low Voltage
SIDETONE AMPLIFIER
V
TR
Z
ac
G
V (TX)
V
BIAS (SPM)
V
BIAS (TM)
V
OL (SPM)
V
OL (SPM)
R
I (TXI)
V
BIAS (AM)
I
SOURCE (SM)
I
SOURCE (PTM)
V
OH (AM)
V
OL (AM)
IL = 5.0mA
IL = 10mA
IL = 20mA
IL = 40mA
IL = 60mA
IL = 20mA
IL = 60mA
20mA < IL , 60mA
TXI to TXO
Speech/Pulse Mode
Tone Mode
Speech/Pulse Mode
Speech/Pulse Mode
All Mode
Speech Mode
Pulse/tone Mode
All Mode
All Mode
−
−
−
−
−
−
−
−
24
0.45
VR −25
VR −25
−
−
0.45
1.5
200
VR −100
−
2.4
3.9
4.6
5.6
6.6
750
300
1650
26
0.52
VR −5.0
VR −5.0
125
10
0.52
2.0
400
VR −50
50
−
−
−
−
−
−
−
−
28
0.60
−
−
250
−
0.60
−
−
−
150
V
W
dB
xV
mV
mV
mV
kΩ
xV
mA
µ A
mV
mV
DC
R
R
Gain (TXO to STA)
Speech Mode
Gv
(STA)
Speech Mode
Pulse Mode
Pulse Mode
STA Bias Voltage V
BIAS (STA)
MICROPHONE, RECEIVER CONTROLS
MIC Saturation Voltage V
MIC Leakage Current I
MAT Resistance R
RMT Delay t
SAT (MIC)
LKG (MIC)
RMT (SM)
R
RMT (DM)
D (RMT)
EQUALIZATION AMPLIFIER
GAIN (V + to EQ)
Speech Mode
Speech Mode
G
V (EQ)
Pulse Mode
Pulse Mode
@VLR = 0.5V
@VLR = 2.5V
@VLR = 0.2V
@VLR = 1.0V
−
−
−
−
−15
−21
−15
−21
−
−
dB
−
−
All Modes 0.65 0.8 0.9 xV
Speech Mode,1 = 500µA − 50 125 mV
Dialing Mode,Pin 1=3.0V − 0 5.0 µA
Speech Mode
Dialing Mode
−
5.0
8.0
10
15
18
Ω
kΩ
Dialing to Speech 2.0 4.0 20 ms
@ VLR = 0.5V
@ VLR = 2.5V
@ VLR = 0.2V
@ VLR = 1.0V
−
−
−
−
−12
−2.5
−12
−2.5
−
−
dB
−
−
R
3
Page 4
S1T2425A SPEECH NETWORK WITH DIALER INTERFACE
ELECTRICAL CHARACTERISTICS (Ta = 25°C) (Continued)
Characteristic Symbol Test Conditions Min. Typ. Max. Unit
EQ Bias Voltage
Speech Mode
Pulse Mode
Speech, Pulse Mode
DIALING INTERFACE
V
BIAS (EQ)
@ VLR = 0.5V
@ VLR = 0.5V
@ VLR = 2.5V
−
−
−
0.66
1.3
3.3
−
−
V
dc
−
MT Input Resistance R
MT Input High Voltage V
MT Input Low Voltage V
MS Input Resistance R
MS Input High Voltage V
MS Input Low Voltage
TI Input Resistance
DTMF Gain G
LINE INTERFACE
V+ Current (Pin 12 Grounded)
Speech Mode
Speech/Pulse Modes
Tone Mode
V+ Voltage
Speech/Pulse Mode
Speech/Pulse Mode
Speech/Pulse Mode
Tone Mode
Tone Mode
LR Level Shift
Speech/Pulse Mode
Tone Mode
1 (MT)
IH (MT)
IL (MT)
I (MS)
IH (MS)
V
IL MS)
R
I (T1)
V (MF)
1+ V+ = 1.7V
V+ = 12V
V+ = 12V
IL = 20mA
V+
IL = 30mA
IL = 120mA
IL = 20mA
IL = 30mA
∆ V
LR
V + -V
LR
− 50 100 − k Ω
− V DD-0.3 − − V
− - − 1.0 V
− 280 600 − k Ω
− 2.0 − − V
−
−
−
−
−
1.25
0.3−V
kΩ
− 3.2 4.8 6.2 dB
4.5
5.5
6.0
2.6
3.0
7.0
4.1
4.5
−
−
7.1
8.4
8.8
3.2
3.7
8.2
4.9
6.4
2.7
4.3
9.0
12.5
14.0
3.8
4.4
9.5
5.7
6.2
−
−
mA
V
V
dc
dc
dc
dc
dc
dc
LC Terminal Resistance R
VOLTAGE REGULATORS
VR Voltage
Load Regulation
Line Regulation
V
Voltage
DD
Load Regulation (Dialing Mode)
Line Regulation (All Modes)
Max. Output Current
Max. Output Current
VDD Current Leakage I
NOTE: Typicals are tested or guaranteed.
4
V
∆ V
∆ V
V
∆ V
∆ V
I
OSM (MAX)
I
ODM (MAX)
LKG (VDD)
LC
R
O
O
DD
O (DM)
O (AM)
- 36 57 94 KΩ
(V+ = 1.7V)
0mA < IR < 1.6mA
2.0V < V + < 6.5V
(V+ = 4.5V)
0 < IDD < 1.6mA
4.0V < V + < 9.0V
Speech Mode
Dialing Mode
1.1
−
−
3.0
−
−
375
1.6
1.2
20
25
3.3
0.25
50
550
2.0
1.3
−
−
3.8
−
−
1000
3.6
V
mV
mV
V
dd
V
dd
mV
µ A
mA
V + = 0, VDD = 3.0V − − 1.5 µA
dc
Page 5
SPEECH NETWORK WITH DIALER INTERFACE S1T2425A
TEST CIRCUIT
V+
14 13 12
22K
16
V
IN
400mVrms
1.0V
KA2425A
S1T2425A
18 17 10
204
Figure 1. DTMF Driver Test
+
20µ F
Ω
47
I
600Ω
LOOP
20mVrms
1KHz
V+
10K
Vs
Microphone Equivalent
150K
8.2K
2
6
503
33K
4 7 8
KA2425A
S1T2425A
14 15 17
+
20µ F
I
LOOP
600Ω
203
150Ω
3 11
18 13
12
10
47Ω
Figure 2. Transmit and sidetone level test
204
10
150Ω
503
5
Page 6
S1T2425A SPEECH NETWORK WITH DIALER INTERFACE
20mVrms
1KHz
150K
8.2K
4 7 8
2
6
14 15 17
20µF
+
203
Vs
503
KA2425A
I
LOOP
33K
S1T2425A
3 11
12
10
18 13
47Ω
V+
Figure 3. Impedance, Receive and Sidetone Rejection Test
204
150
10
503
Ω
6
Page 7
SPEECH NETWORK WITH DIALER INTERFACE S1T2425A
APPLICATION CIRCUIT
H/S SW
TIP
RING
- +
102
103
383 383
393
220K
4.7K 3.3K
68Ω, 1/2
33µ F
+
+
22µ F
120K
6
4
15
KA2425A
S1T2425A
13
12
11
8.2K
14
223
1
102
2
200Ω 2.2K
3
7
8
9
10
47µ F
+
472
MIC
SPEAKER
7