![](http://datasheet.mmic.net.cn/370000/TEA1096_datasheet_16738776/TEA1096_16.png)
November 1994
16
Philips Semiconductors
Product Specification
Speech and listening-in IC
TEA1096; TEA1096A
Fig.16 Loudspeaker amplifier channel.
Dynamic limiter/loudspeaker amplifier disabling;
pin DLL/DIL
The dynamic limiter in the loudspeaker channel of the
TEA1096/TEA1096A prevents clipping of the loudspeaker
output stage and protects the functioning of the circuit
when low supply conditions are detected.
Hard clipping of the loudspeaker output stage is prevented
by rapidly reducing the gain when the output stage starts
to saturate. The time in which the gain reduction is effected
(clipping attack time) is approximately a few milliseconds.
The loudspeaker amplifier stays in the reduced gain mode
until the peaks of the loudspeaker signals no longer start
to cause saturation. The gain of the loudspeaker amplifier
then returns to its normal value within the clipping release
time. Both attack and release time are proportional to the
value of the capacitor C
DLL
. The THD of the loudspeaker
amplifier in the reduced gain mode stays below 5% up to
10 dB of input voltage overdrive.
When the supply conditions drop below the required level,
the gain of the loudspeaker amplifier is reduced in order to
prevent the device from malfunctioning. When the supply
current drops below the required level, the supply voltage
V
BB
decreases. In this condition, the gain of the
loudspeaker amplifier is reduced slowly (approximately a
few seconds). When the supply voltage continues to
decrease and drops below an internal threshold of 2.8 V,
the gain of the loudspeaker amplifier is rapidly reduced
(approximately 1 ms). After returning to normal supply
conditions, the gain of the loudspeaker amplifier is raised
again.
The dynamic limiter also provides a loudspeaker disable
when pin DLL/DIL is short-circuited to V
EE
. The
loudspeaker gain is then typically 80 dB lower. The
release time is approximately 10 ms.