1
ICs for Telephone
n Overview
The AN6426NK incorporates both speech network and
hands-free functions. Its well designed block configura-
tion allows realization of a hands-free telephone with a
minimal number of components.
n Features
• Incorporates all the functions required of a hands-free
telephone.
• Incorporates all the functions required of a handset.
• Complies with AC and DC impedance requirements.
• Provides a wide dynamic range.
• A noise detecting circuit prevents inadvertent transmis-
sion.
• Operation on an external power supply is available.
• Each mode can be easily controlled.
• A built-in loudspeaker amplifier can operated either on
line voltage or an external power supply.
AN6426NK
Hands-free Speech Network IC
Unit : mm
SDIP package with 42 pins (SDIP042-P-0600A)
3 to 15 15.3– 0.25
0.3
+0.1
– 0.05
13.7– 0.3
36.8
–
0.3
1
21
42
22
0.9
–
0.25
0.5
–
0.1
4.76– 0.25
4.5– 0.25
0.96– 0.25
–
+
+
–
+
–
+
–
–
+
–
+
T
Log
Send
AP
–
+
AP
Buff-
er
38 39 19 14 15 41 42 36 34 29 6 5 35 1
33
32
31
30
20
21
22
23
26
2543287910
11
27
28
24
17
16
18
13
12
40
37
Vrl
VB
VB
VB
VL VCC1 VCC2 GND
VB
Vr2
Vr1
Vr1
VCC1
Vr1
AGC
MA2
MA1
TATT
Vrl
R
Log
Rec
Pre
Vrl
Power
Regulator
Power
Regulator
Matrix
Circuit
Matrix
Circuit
RATT
–
+
S.Amp
Rec.2Rec.1
Buffer
Attenator
Control
Power
Regulator
Comp
n Block Diagram