TEA7063 Просмотр технического описания (PDF) - STMicroelectronics
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TEA7063 Datasheet PDF : 15 Pages
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In this condition an internal connection is acti-
vated from line DTMF output (pin 16) to Receive
Output (pin 20) with an attenuation GRS = 38.5dB
to provide acoustic feedback of the DTMF emis-
sion.
4. A.G.C AND SIDETONE PROGRAMMING
4.1 Programmable Controls
AGC and sidetone attack and disonnect points (or
currents) are programmable externally through
two independents pins, I-start (pin 9) and I-slope
(pin 15).
4.2 I-Start (pin 9)
An external resistor RLL connected between I-
start (pin 9) and Microprocessor Supply (pin 19)
controls the attack point of AGC and ZAL (an-
tisidetone Z).
ILL is the line current at which the control starts.
Formulas for ILL and RLL with R9 = 100K are:
ILL
=
2880
RLL
+
11mA
RLL =
2880
( ILL − 11mA )
4.3 I-Slope (pin 15)
An external resistor RLS connected between
I-slope (pin 15) and Microprocessor Supply (pin
19) controls the disconnected point of AGC and
Figure 7
TEA7063
ZAS (antisidetone Z). ILS is the line current at
which the control stops. Formulas for ILS and
RLS with R9 = 100K are:
ILS
=
4680
RLS
+
ILL;
RLS =
4680
( ILS − ILL )
4.4 A.G.C. OFF (pin 9 and 15)
Programming ILL and ILS respectively higher
than 70mA and 450mA is forcing the IC in AGC
OFF Condition.
Suggested external components are:
RLL = 51KΩ and RLS = 10KΩ
In this case sending, receiving gain and sidetone
compensation are independent of the line lenght.
Pins 1 and 2 can be connected to each other sav-
ing 5 passive external components at pin 2.
4.5 Secret Function for Private (pin 14)
The two separate thresholds for sending and Re-
ceiving Mute (pin 14) allow ”Secret Function”
(only microphone muted).
Pin 14 can be set:
a) between 0.25V and 0.8V for speech mode,
b) between 1.6V and 2.1V for ”secret” mode (mi-
crophone muted),
c) between 2.7V and 3.3V for ”all muted” mode
9/15
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