DatasheetQ Logo
Electronic component search and free download site.
Transistors,MosFET ,Diode,Integrated circuits

TEA1093T View Datasheet(PDF) - Philips Electronics

Part Name
Description
Manufacturer
TEA1093T
Philips
Philips Electronics Philips
TEA1093T Datasheet PDF : 28 Pages
1 2 3 4 5 6 7 8 9 10 Next Last
Philips Semiconductors
Hands-free IC
Product specification
TEA1093
FUNCTIONAL DESCRIPTION
The values given in the functional description are typical
values except when otherwise specified.
A principle diagram of the TEA106X is shown on the left
side of Fig.3. The TEA106X is a transmission circuit of the
TEA1060 family intended for hand-set operation. It
incorporates a receiving amplifier for the earpiece, a
transmit amplifier for the microphone and a hybrid. For
more details on the TEA1060 family, please refer to “Data
Handbook IC03”. The right side of Fig.3 shows a principle
diagram of the TEA1093, a hands-free add-on circuit with
a microphone amplifier, a loudspeaker amplifier and a
duplex controller.
As can be seen from Fig.3, a loop is formed via the
sidetone network in the transmission circuit and the
acoustic coupling between loudspeaker and microphone
of the hands-free circuit. When this loop gain is greater
than 1, howling is introduced. In a full duplex application,
this would be the case. The loop-gain has to be much
lower than 1 and therefore has to be decreased to avoid
howling. This is achieved by the duplex controller.The
duplex controller of the TEA1093 detects which channel
has the ‘largest’ signal and then controls the gain of the
microphone amplifier and the loudspeaker amplifier so that
the sum of the gains remains constant. As a result, the
circuit can be in three stable modes:
1. Transmit mode (Tx mode): the gain of the microphone
amplifier is at its maximum and the gain of the
loudspeaker amplifier is at its minimum.
2. Receive mode (Rx mode): the gain of the loudspeaker
amplifier is at its maximum and the gain of the
microphone amplifier is at its minimum.
3. Idle mode: the gain of the amplifiers is halfway
between their maximum and minimum value.
The difference between the maximum gain and minimum
gain is called the switching range.
handbook, full pagewidth
telephone
line
HYBRID
sidetone
TEA106X
DUPLEX
CONTROL
TEA1093
acoustic
coupling
MGD218
Fig.3 Hands-free telephone set principles.
1996 Feb 09
6
 

Share Link: 

datasheetq.com  [ Privacy Policy ]Request Datasheet ] [ Contact Us ]