tea1094a NXP Semiconductors, tea1094a Datasheet - Page 7

• Manufacturer Part Number: tea1094a
• Description: Hands Free Ic
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Supply: pins V
The TEA1094 and TEA1094A must be supplied with an
external stabilized voltage source between pins V
GND. In the idle mode, without any signal, the internal
supply current is 3.1 mA at V
To reduce the current consumption during pulse dialling or
register recall (flash), the TEA1094A is provided with a
power-down (PD) input. When the voltage on PD is HIGH
the current consumption from V
Microphone channel: pins MIC, GAT, MOUT, MICGND
and MUTET (see Fig.5)
The TEA1094 and TEA1094A have an asymmetrical
microphone input MIC with an input resistance of 20 k .
The gain of the input stage varies according to the mode
of the TEA1094 and TEA1094A. In the transmit mode, the
gain is at its maximum; in the receive mode, it is at its
minimum and in the idle mode, it is halfway between
maximum and minimum.
1996 Jul 15
handbook, full pagewidth
Hands free IC
BB
telephone
, GND and PD
line
BB
sidetone
BB
= 5 V.
is 180 A.
Fig.4 Hands-free telephone set principles.
HYBRID
TEA106x
BB
and
7
Switch-over from one mode to the other is smooth and
click-free. The output capability at pin MOUT is
20 A (RMS).
In the transmit mode, the overall gain of the microphone
amplifier (from pins MIC to MOUT) can be adjusted from
0 dB up to 31 dB to suit specific application requirements.
The gain is proportional to the value of R
15.5 dB with R
A capacitor must be connected in parallel with R
ensure stability of the microphone amplifier. Together with
R
By applying a HIGH level on pin MUTET, the microphone
amplifier is muted and the TEA1094 and TEA1094A are
automatically forced into the receive mode.
GAT
TEA1094A
CONTROL
TEA1094
DUPLEX
, it also provides a first-order low-pass filter.
GAT
= 30.1 k .
TEA1094; TEA1094A
MGE438
coupling
acoustic
Product specification
GAT
and equals
GAT
to