TEA1111AT/C2,518 NXP Semiconductors, TEA1111AT/C2,518 Datasheet - Page 9

• Manufacturer Part Number: TEA1111AT/C2,518
• Description: Speech Network Advanced 45.2dB 16-Pin SO T/R
• Manufacturer: NXP Semiconductors

Specifications of TEA1111AT/C2,518

• Package: 16SO
• Applications: Answering Machines|Cordless Telephones|Fax Machines|Telephone Sets
• Maximum Receiver Gain: 28.4 dB
• Maximum Transmitter Gain: 45.2 dB
• Typical Supply Current: 1.15|-1 mA
• Typical Operating Supply Voltage: 3.25|3.3 V

Philips Semiconductors
Transmit stage (pins MIC+, MIC and DTMF)
M
The TEA1111A has symmetrical microphone inputs.
The input impedance between pins MIC+ and MIC is
68 k (2
to pin LN is set at 44.2 dB (typical) at 600
Automatic gain control is provided on this amplifier for line
loss compensation.
DTMF
When the DTMF amplifier is enabled, dialling tones may
be sent on line. These tones are also sent to the receive
output QR at a low level (confidence tone), the level is
controlled by pin VCI.
The TEA1111A has an asymmetrical DTMF input. The
input impedance between DTMF and V
is biased at V
is set at 25.9 dB.
Automatic gain control has no effect on the DTMF
amplifier.
2000 Feb 18
ICROPHONE AMPLIFIER
handbook, halfpage
Speech circuit with dialler interface, regulated
supply and earpiece volume control
I LEDC
( A)
AMPLIFIER
500
400
300
200
100
Fig.8 LEDC current versus line current.
0
34 k ). The voltage gain from pins MIC+/MIC
0
EE
. The voltage gain from pin DTMF to pin LN
(
PIN
20
DTMF)
(
PINS
40
MIC+
60
AND
EE
I line (mA)
MIC )
80
is 20 k and it
line load.
FCA057
100
9
Receiving stage (pins IR, GAR, QR and VCI)
The receive part consists of an earpiece amplifier and a
volume control block.
E
The earpiece amplifier has one input (IR) and one output
(QR). The input impedance between pin IR and pin V
22 k . When pin VCI is tied to V
pin IR to pin QR is set at 27.4 dB (typical) which reduces
the attenuation of the receive signal by the anti-sidetone
network from 32 dB to 4.6 dB. The gain can be decreased
by connecting an external resistor R
GAR and QR; the adjustment range is 6 dB. Two external
capacitors C
and C
ensure stability. Capacitor C
low-pass filter. The cut-off frequency corresponds to the
time constant C
resistor (123 k typical) which sets the gain. The
relationship C
ensure stability.
handbook, halfpage
ARPIECE AMPLIFIER
L
R
R
Fig.9 Equivalent impedance between LN and V
EQ
P
P
= internal resistance.
= 17.5 k .
GARS
= C
REG
(connected between pins GAR and V
GAR
GARS
R
V EE
SLPE
LN
GAR
SLPE
(connected between pins GAR and QR)
= 10
R
P
R
.
L EQ
R SLPE
20
GARint
V ref
C
GAR
GAR
. Where R
REG
4.7 F
R P
C REG
must be complied with to
EE
provides a first-order
, the voltage gain from
GARext
Product specification
GARint
TEA1111A
V CC
R CC
100 F
619
C VCC
MBE788
between pins
is the internal
EE
)
EE
EE
.
is