TEMIC U4090B Technical data
查询U2090B供应商
Monolithic Integrated Feature Phone Circuit
Description
The µc controlled telephone circuit U4090B is a linear
integrated circuit for use in feature phones, answering
machines and fax machines. It contains the speech circuit,
tone ringer interface with dc/dc converter, sidetone
equivalent and ear protection rectifiers. The circuit is line
powered and contains all components necessary for
amplification of signals and adaptation to the line.
Features
D
DC characteristic adjustable
D
Transmit and receive gain adjustable
D
Symmetrical input of microphone amplifier
D
Anti-clipping in transmit direction
D
Automatic line loss compensation
D
Symmetrical output of earpiece amplifier
An integrated voice switch with loudspeaker amplifier
allows loudhearing or handsfree operation. With an
anti-feedback function, acoustical feedback during
loudhearing can be reduced significantly. The generated
supply voltage is suitable for a wide range of peripheral
circuits.
D
Voice switch
D
Tone ringer interface with dc/dc converter
D
Zero crossing detection
D
Common speaker for loudhearing and tone ringer
D
Supply voltages for all functional blocks of a
subscriber set
U4090B
D
Built-in ear protection
D
DTMF and MUTE input
D
Adjustable sidetone suppression independent
of sending and receiving amplification
D
Speech circuit with two sidetone networks
D
Built-in line detection circuit
D
Integrated amplifier for loudhearing operation
D
Anti-clipping for loudspeaker amplifier
D
Improved acoustical feedback suppression
D
Power down
Applications
Feature phone, answering machine, fax machine, speaker
phone
Speech
circuit
Voice
switch
Audio
amplifier
Tone
ringer
Loudhearing
and
Tone ringing
MC with
EEPROM/
DTMF
D
Integrated transistor for short circuiting the line
voltage
D
Answering machine interface
D
Operation possible from 10 mA line currents
Benefits
D
Savings of one piezo electric transducer
D
Complete system integration of analog signal processing on one chip
D
Very few external components
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
94 8741
1 (34)
Preliminary Information
U4090B
Block Diagram
MPS
V
MP
14 13
V
B
11
V
10
SENSE
7
IND
31
AGA
21
IMPSEL
L
8
33
W
600
M
V
34
Power
supply
W
900
GND
9
control
Impedance
6
L
V
Current
PD
Q
32
supply
S
L
I
I
REF
20
I Supply
Line
AGA
LIDET
17
detect
control
RING
V
16
OSC
C
15
MP
V
Receive
attenuation
SW
OUT
RA1
RFDO
19
–
+
–
+
–
+
ST
BAL
THA
18
–
+
43
RECIN
STIS
37
38
STIL
RAC
3941
GR
40
RECO1
GT MICOTXIN STO V
94 8064
RA2
–1
MIC
5
TXA
MIC1
4
DTMF
MIC2
2
DTMF
TX
TTXA
ACL
42
28
27
INLDR
INLDT
mute
Transmit
control
feedback
Acoustical
suppression
30
29
TLDT
TLDR
control
26
ATAFS
12
SA
SAO
Mute
SACL
22
TSACL
control
receive
SAI
24
SAI
44
3
1
36
RECO2
35
MUTR
25
MUTX
GSA
23
Figure 1.
2 (34)
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
Preliminary Information
Tip
hook switch
U4090B
7
C
Ring
5
R
9
C
1
Q
1
L
MP
V
Micro
controller
19
12
16
C
speaker
R
22
7
10
38
39
40 41
36
35
25
23
C
R
13
C
11
R
R
R
14
C
17
R
14
R
15
R
16
R
18
43
37
24
15
C
M
V
10
12
13
L
V
STIN 2
(Option)
R
M
V
11
8
C
9
R
12
C
Earpeace
94 8849
STO
M
V
C
m
to C
6
5 C
C
4
C
4
R
3
R
3
C
2
R
13 V
2
C
1
C
1
R
M
V
to STIN
28
R
11 14 13
10
7
31
21
8
33
44
3
1
Micro–
phone
34
5
9
4
27
R
DTMF
Generator
6
R
6
32
20
17
16
15
U4090B
2
42
21
C
R
C
22
C
28
20
20
RECO
27
19
R
MICO
30
18
C
19
C
26
29
31
17
R
C
Loud-
M
8
V
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
Figure 2. Application circuit for loudhearing
3 (34)
Preliminary Information
U4090B
Tip
hook switch
M
V
Ring
7
C
5
R
M
V
8
m
C
to C
6
C
5
C
4
C
4
R
3
3
R
C
2
R
13 V
2
C
1
C
1
R
C
25
R
26
R
25
R
DTMF
to STIN
Micro–
24
C
11 14 13
10
21 31 7
8
33
44
3
1
phone
24
C
HF–Mic
23
9
34
5
4
23
R
6
R
6
20
32
2
22
R
28
42
21
C
30
R
27
C
RECO
17
29
R
9
C
1
Q
16
15
U4090B
27
30
17
18
C
C
26
C
LOGTX
1
L
7
R
19
29
26
12
18
R
16
C
Loud
22
15
C
speaker
18
43
37
38
41 39
40
36
35
25
23
24
14
C
17
R
M
V
B
V
10
C
10
R
13
C
11
R
12
R
13
R
14
R
15
R
16
R
L
V
STIN 2
(Option)
MP
V
Micro–
21
R
LOGTX
8
R
9
R
M
V
Earpiece
94 8850
controller
BC177
11
C
12
C
STN
M
V
4 (34)
Figure 3. Application for handsfree operation
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
Preliminary Information
Typical value of external components
U4090B
C
1
C
2
C
3
C
4
C
5
C
6
C
7
C
8
C
9
C
10
C
11
C
12
C
13
C
14
C
15
C
16
C
17
C
18
C
19
C
20
C
21
C
22
C
23
C
24
C
25
C
26
C
27
L
1
R
1
R
2
100 nF
4.7 nF
10 mF
220 mF
47 mF
470 mF
820 nF
100 mF
100 nF
150 nF
68 nF
33 nF
10 mF
100 nF
1 m
F
47 mF
10 mF
10 m
F
68 nF
68 nF
1 mF
100 nF
6.8 nF
10 nF
100 nF
470 nF
33 nF
2.2 mH
27 k
W
20 k
W
R
3
R
4
R
5
R
6
R
7
R
8
R
9
R
10
R
11
R
12
R
13
R
14
R
15
R
16
R
17
R
18
R
19
R
20
R
21
R
22
R
23
R
24
R
25
R
26
R
27
R
28
R
29
R
30
R
31
> 68 k
10
W
1.5 k
62 k
W
680 k
22 k
W
330
W
3 k
W
62 k
W
30 k
W
62 k
W
120 k
47 k
W
1 k
W
1.2
W
30 k
W
6.8 k
6.8 k
15 k
W
330 k
220 k
68 k
W
2 k
W
3.3 k
18 k
W
2 k
W
1 k
W
12 k
W
56 k
W
W
W
W
W
W
W
W
W
W
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
5 (34)
Preliminary Information
U4090B
G
DTMF
MICO
MIC2
MIC1
PD
IND
V
GND
SENSE
V
SAO
V
MPS
V
MP
SWOUT
COSC
VRING
THA
RFDO
LIDET
IMPSEL
TSACL
Pin Description
T
1
2
3
4
5
6
7
8
L
9
10
11
B
U4090B
12
13
14
15
16
17
18
19
20
21
22
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
TXIN
RECIN
TTXA
G
R
RECO1
RAC
STIL
STIS
RECO2
MUTR
V
M
STO
IREF
AGA
TLDR
TLDT
INLDR
INLDT
ATAFS
MUTX
SAI
GSA
Pin Symbol Function
1 G
2 DTMF Input for DTMF signals,
3 MICO Output of microphone preamplifier
4 MIC 2 Non-inverting input of microphone
5 MIC 1 Inverting input of microphone
6 PD Active high input for reducing the
7 IND The internal equivalent inductance of
8 V
9 GND Reference point for dc- and ac-output
10 SENSE A small resistor (fixed) connected
11 V
12 SAO Output of loudspeaker amplifier
13 V
14 V
SWOUT
15
16 COSC 40 kHz oscillator for ringing power
A resistor from this pin to GND sets the
T
amplification of microphone and DTMF
signals, the input amplifier can be muted
by applying VMP to G
also used for the answering machine
and handsfree input
amplifier
amplifier
current consumption of the circuit,
simultaneously V
internal switch
the circuit is proportional to the value
of the capacitor at this pin,
a resistor connected to ground may be
used to reduce the dc line voltage
Line voltage
L
signals
from this pin to V
the dc characteristic and also effects
the line length equalization
characteristics and the line current at
which the loudspeaker amplifier is
switched on
Unregulated supply voltage for
B
peripheral circuits (voice switch),
limited to typically 7 V
Unregulated supply voltage for µP,
MPS
limited to 6.3 V
Regulated supply voltage 3.3 V for
MP
peripheral circuits (especially
microprocessors),
minimum output current: 2 mA
(ringing)
4 mA (speech mode)
Output for driving external switching
transistor
converter
T
is shorted by an
L
sets the slope of
L
.
6 (34)
94 7905 e
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
Preliminary Information
U4090B
Pin Symbol Function
17 VRING Input for ringing signal protected by
internal zener diode
18 THA Threshold adjustment for ringing
frequency detector
19 RFDO Output of ringing frequency detector
20 LIDET Line detect; output is low when the
line current is more than 15 mA
21 IMP-
SEL
22 TSACL Time constant of anti-clipping of
23 GSA Current input for setting the gain of
24 SA I Speaker amplifier input (for
25 MUTX Three state input of transmit mute:
26 ATAFS Attenuation of acoustical feedback
27 INLDT Input of transmit level detector
28 INLDR Input of receive level detector
Control input for selection of line
impedance
1. 600 Ω
2. 900 Ω
3. Mute of second transmit stage
(TXA); also used for indication of
external supply (answering machine);
last chosen impedance is stored
speaker amplifier
the speaker amplifier,
adjustment characteristic is
logarithmical,
or RGSA > 2 MΩ, the speaker
amplifier is switched off
loudspeaker, tone ringer and
handsfree use)
1) Speech condition; inputs MIC1 /
MIC2 active
2) DTMF condition; input DTMF
active
a part of the input signal is
passed to the receiving amplifier
as a confidence signal during
dialing
3) Input DTMF used for answering
machine and handsfree use;
receive branch not affected
suppression,
maximum attenuation of AFS circuit
is set by a resistor at this pin,
without the resistor, AFS is switched
off
Pin Symbol Function
29 TLDT Time constant of transmit level
detector
30 TLDR Time constant of receive level
detector
31 AGA Automatic gain adjustment with line
current
a resistor connected from this pin to
GND sets the starting point
max. gain change: 6 dB.
32 IREF Internal reference current generation;
RREF = 62 kΩ; IREF = 20 µA
33 STO Side tone reduction output
output resistance is approx. 300 Ω,
maximum load impedance: 10 kΩ.
34 V
35 MUTR Three state mute input
36 RECO 2 Inverting output of receiving
37 STI S Input for side tone network (short
38 STI L Input for side tone network (long
39 RAC Input of receiving amplifier for ac
40 RECO 1 Output of receiving amplifier
41 G
42 TTXA Time constant of anticlipping in
43 RECIN Input of receiving path; input
44 TXIN Input of intermediate transmit stage,
Reference node for microphone-
M
earphone and loudspeaker amplifier,
supply for electret microphone
(IM ≤ 700 mA)
1. Normal operation
2. Mute of ear piece
3. Mute of RECIN signal
Condition of earpiece mute is stored
amplifier
loop) or for answering machine
loop)
coupling in feedback path
A resistor connected from this pin to
R
GND sets the receiving amplification
of the circuit; amplifier RA1 can be
muted by applying VMP to GR
transmit path
impedance is typically 80 k
input resistance is typically 20 kΩ
W
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
7 (34)
Preliminary Information
U4090B
DC line interface and supply voltage generation
The DC line interface consists of an electronic inductance
and a dual port output stage, which charges the capacitors
at V
and VB. The value of the equivalent inductance
MPS
is given by
L = R
SENSE
@ C
@ (RDC @ R30) / (R
IND
+ R30)In
DC
order to improve the supply during worst case operating
conditions two PNP current sources - I
V
L
10
W
SENSE
BOPT
and
I
MPSOPT
voltages, when the NPNs in parallel are unable to conduct
current.
A flowchart for the control of the current sources
(figure 5) shows, how a priority for supply V
achieved.
- hand an extra amount of current to the supply
MPS
is
R
SENSE
C
IND
m
10 F
IND
R
DC
Figure 4. DC line interface with electronic inductance and generation of a regulated and an unregulated supply
I
< 5 mA
=
94 8047
VMPS < 6.3 V
BOPT
+
–
30 k
R
30
V
W
OFFS
Y
VSENSE–VMPS>200 mV
N
N
–
+
+
–
I
MPSOPT
< 5 mA
=
3.3 V
7.0 V
6.3 V
V
MPS
V
MP
3.3 V/
2 mA
V
B
470 F
m
47 F
m
220 F
m
8 (34)
Y
Charge CMPS
(IMPSOPT)
94 8058
Figure 5. Supply capacitors CMPS and CB are charged with priority on CMPS
VSENSE–VB>200 mV
Y
VB < 6.3 V
Y
Charge CB
(IBOPT)
N
N
IMPSOPT = 0
IBOPT = 0
Reduce IBOPT
(IMPSOPT = 0)
TELEFUNKEN Semiconductors
Preliminary Information
Rev . C1, 28-Oct-96
U4090B
The U4090B contains two identical series regulators,
which provide a supply voltage V
of 3.3 V suitable for
MP
a microprocessor. In speech mode both regulators are
active, because V
and VB are charged simultaneously
MPS
by the DC-line interface. Output current is 4 mA. The
capacitor at V
is used to provide the microcomputer
MPS
with sufficient power during long line interruptions. Thus
long flash pulses can be bridged or a LCD display can be
turned on for more than 2 seconds after going on hook.
When the system is in ringing mode, V
is charged by the
B
on chip ringing power converter. In this mode only one
regulator is used to supply V
V
RING
V
L
QS
with max. 2 mA.
MP
RPC
Power
supply
Supply structure of the chip
As a major benefit the chip uses a very flexible system
structure, which allows simple realization of numerous
applications such as:
group listening phone
handsfree phone
ringing with the built in speaker amplifier
answering machine with external supply
The special supply topology for the various functional
blocks is illustrated in figure 6.
Voltage
regulator
Voltage
regulator
7 V
6.3 V
V
V
V
B
MP
MPS
PD
LIDET
RFDO
LIDET
V
Lon
RFD
Figure 6. Supply of functional blocks is controlled by input voltages VL, VB, V
TXA
TXACL
and by logic inputs PD and IMPSEL
OFFSA
COMP
There are four major supply states:
1. Speech condition
2. Power down (pulse dialing)
3. Ringing
4. External supply
1. In speech condition the system is supplied by the line
current. If the LIDET-block detects a line voltage
above the fixed threshold (1.9 V), the internal signal
VLON is activated, thus switching off RFD and RPC
and switching on all other blocks of the chip.
ES
SAI,SA
SACL
AFS
IMPED
CONTR
MIC, DTMF
AGA, RA1, RA2
TX MUTE
MUT REC, STBAL
RECATT
ring
IMPSEL
94 8046
For line voltages below 1.9 V the switches remain in their
quiescent state as shown the diagram.
OFFSACOMP disables the group listening feature (SAI,
SA, SACL, AFS) below line currents of approximately
10 mA.
2. When the chip is put into Power-down mode
(PD = high), e.g. during pulse dialing, the internal
switch QS shorts the line and all amplifiers are
switched off. In this condition LIDET, voltage
regulators and IMPED CONTR are the only active
blocks.
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
9 (34)
Preliminary Information
U4090B
3. During ringing the supply for the system is fed into V
via the ringing power converter (RPC). The only
functional amplifiers are found in the speaker
amplifier section (SAI, SA, SACL).
4. In an answering machine the chip is powered by an
external supply via pin V
a posibility to activate all amplifiers (except the
transmit line interface TXA). Selecting IMP-
. This application demands
B
Handset
microphone
Log
B
SEL = high impedance activates all switches at the ES
line.
Acoustic feedback suppression
Acoustical feedback from the loudspeaker to the handset
microphone may cause instability in the system. The
U4090B offers a very efficient feedback suppression
circuit, which uses a modified voice switch topology.
figure 8 shows the basic system configuration.
TX
Att
Hybrid
Att
contr
Line
Loudspeaker
Figure 5. Basic voice switch system
Two attenuators (TX ATT and RX ATT) reduce the
critical loop gain by introducing an externally adjustable
amount of loss either in the transmit or in the receive
path.The sliding control in block ATT CONTR
determines, wether the TX or the RX signal has to be
attenuated. The overall loop gain remains constant under
all operating conditions.
Selection of the active channel is made by comparison of
Log
RX
Att
94 8956
the logarithmically compressed TX- and RX- envelope
curve.
The system configuration for group listening, which is
realized in the U 4090 B, is illustrated in figure 9. TXA
and SAI represent the two attenuators, whereas the
logarithmic envelope detectors are shown in a simplified
way (operational amplifiers with two diodes).
10 (34)
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
Preliminary Information
U4090B
VL
94 8059
SAO
GSA
GT MICO TIN INLDT TLDT
–
VBG
+
AFS
control
Max
att.
–
VBG
SAI
TLDR RECO1
SAI
+
INLDR
AGA
STO VL
TXA
GR
STIS
STN
Zint
RECIN
STO
Z
L
Figure 6. Integration of acoustic feedback suppression circuit into the speech circuit environment
A detailed diagram of the AFS (acountic feedback
suppression) is given in figure 10. Receive and Transmit
signals are first processed by logorithmic rectifiers in
TELEFUNKEN Semiconductors
Rev . C1, 28-Oct-96
Preliminary Information
order to produce the envelopes of the speech at TLDT and
RLDT. After amplification a decision is made by the
differential pair, which direction should be transmitted.
11 (34)
Loading...