Annual report 2000 - Europractice
Annual report 2000 - Europractice
Annual report 2000 - Europractice
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Multichannel speech transmission circuit for use in local communication systems<br />
Application<br />
ASIC LHRA is a multichannel<br />
speech transmission circuit for use<br />
in local communication systems.<br />
Eight audio channels can be transmitted<br />
on a single line. Transmission<br />
principle is a combination of<br />
single side band modulation and<br />
channel switching. Using switched<br />
capacitor filter and switch modulator<br />
technology the integration of<br />
the multichannel parallel transmission<br />
is achieved in a purely analog<br />
way. Up to 512 speech stations can<br />
be connected by a four wire cable<br />
in a local transmission system. Two<br />
cables are used for 12 Volt power<br />
distribution, one cable transmit the<br />
digital information to control the<br />
system and the analog line is used<br />
for the multichannel speech<br />
transmission.<br />
ASIC Description<br />
The device is divided into<br />
a digital and an analog<br />
part. In the digital part, an<br />
18 MHz Q-oscillator generates<br />
the system clock,<br />
which is fed to an external<br />
controller. The digital<br />
control word is used to set<br />
amplifier gain, channel selection<br />
and user notification.<br />
Transmitter and receiver<br />
circuits are the key<br />
blocks of the analog part.<br />
In these parts, modulation<br />
of the audio signal from<br />
the baseband to one of the eight<br />
channels, transmission to the line<br />
and selection and demodulation of<br />
one of the transmitted channels<br />
back to the baseband is managed.<br />
Technology: Austria Mikro Systeme<br />
Int. 0.6µ CMOS<br />
Die size: 9.6 mm 2<br />
Supply voltage: 5 V<br />
Package: PQFP 44<br />
Test: Mixed Signal by DELTA<br />
Why <strong>Europractice</strong> ?<br />
<strong>Europractice</strong> IC service and Fraunhofer<br />
IIS-A could offer design services,<br />
prototyping and the flexibility<br />
of producing 400 tested and<br />
packaged parts for field evaluation<br />
of the ASIC and system.<br />
Production was performed using<br />
MPW multiple placement which<br />
greatly reduced the non-recurring<br />
mask costs.<br />
(By courtesy of Comtech)<br />
X1<br />
X2<br />
CLK<br />
CLK<br />
DATA<br />
DCK<br />
RIN<br />
INMIC<br />
---------<br />
---------------<br />
service<br />
center<br />
FhG-IIS<br />
---------------<br />
Design Partner<br />
Comtech GmbH is a small company<br />
founded in 1993 specialising in<br />
communication and information<br />
systems for home and commercial<br />
use. The mixed mode systems<br />
using the 4 wire bus allow complete<br />
flexibility and simplified installation<br />
compared to simple analog<br />
systems.<br />
For more information contact<br />
Comtech GmbH<br />
Industriestrasse 29<br />
78112 St. Georgen<br />
Germany<br />
Tel.: +49 911 996730<br />
Fax: +49 911 683181<br />
I1MIC<br />
O1MIC<br />
IN<br />
CLOUT<br />
POR<br />
TCOUT<br />
TCIN<br />
Ceramic<br />
Filter<br />
LIN<br />
LOUT<br />
Ceramic<br />
Filter<br />
19<br />
---------<br />
RCOUT1<br />
RCOUT0<br />
RCIN0<br />
Pdx<br />
RCIN1<br />
WD/TST<br />
TEST<br />
EXLS<br />
OUT
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