U4030B
Telephone Speech Circuit
Description
The U4030B is an electronic speech circuit for standard
and feature telephones. It replaces the hybrid transformer,
earphone and microphone interface and the supply
voltage generation for external components, e.g. dialer or
microcomputers. Using the U4030B in telephone circuit
designs can improve transmission quality and results in
cost savings through shorter and more flexible design
procedures. It reduces the amount of external components
needed. The U4030B uses TEMIC’s reliable bipolar
technology and is offered in a SO20 package.
Features
D
Microphone amplifier with
– Symmetrical input
– Privacy function
– Anticlipping
Benefits
D
Independent adjustment of
– Transmission gain
– Receiving gain
– Sidetone suppression
– Frequency response
D
Built in ear protection
D
Power down input
D
Mute input
D
DTMF interface
D
Low line impedance during pulse dialing
D
Low-impedance supply voltage for all external blocks
D
Supply voltage for an electret microphone
Applications
D
D
D
D
Standard telephone
Fax machine
Answering machine
Cordless telephone
Block Diagram
GT
11
DTMF
PRIV
MIC1
MIC2
10
–
+
MICO
9
ST
5
+
–
GR
6
–
+
Ear protection
RECO
7
16
12
13
4
TXA
REC.ATT.
CK
15
Limiter
Mute
3
CLIM
8
MUTE
17
PD
Power supply
U 4030 B
14
GND
18
SWAMP
1
VM
20
VD
19
2
VL
RDC
VC
93 7618 e
Figure 1.
Ordering Information
Extended Type Number
U4030B-AFL
U4030B-AFLG3
Package
SO20
SO20
Remarks
Taped and reeled
Rev. A2, 27-Jan-98
1 (14)
TEMIC [ TEMIC SEMICONDUCTORS ]
