LM1036N National Semiconductor, LM1036N Datasheet - Page 5

• Manufacturer Part Number: LM1036N
• Description: Audio Power Amplifier IC
• Manufacturer: National Semiconductor

Specifications of LM1036N

• No. Of Channels: 2
• Amplifier Case Style: DIP
• No. Of Pins: 20
• Peak Reflow Compatible (260 C): No
• Leaded Process Compatible: No
• Mounting Type: Through Hole
• Package / Case: 20-DIP
• No. Of Amplifiers: 2
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Application Notes
TONE RESPONSE
The maximum boost and cut can be optimized for individual
applications by selection of the appropriate values of C
(treble) and C
The tone responses are defined by the relationships:
Where a
tively and a
For the values of C
in the Application Circuit, 15 dB of boost or cut is obtained at
40 Hz and 16 kHz.
ZENER VOLTAGE
A zener voltage (pin 17=5.4V) is provided which may be
used to bias the control potentiometers. Setting a DC level of
one half of the zener voltage on the control inputs, pins 4, 9,
and 14, results in the balanced gain and flat response con-
dition. Typical spread on the zener voltage is
this must be taken into account if control signals are used
which are not referenced to the zener voltage. If this is the
case, then they will need to be derived with similar accuracy.
Application Circuit
b
=a
b
t
=a
=0 for maximum bass and treble boost respec-
b
t
=1 for maximum cut.
(bass).
b
and C
t
of 0.39 µF and 0.01 µF as shown
±
100 mV and
t
5
LOUDNESS COMPENSATION
A simple loudness compensation may be effected by apply-
ing a DC control voltage to pin 7. This operates on the tone
control stages to produce an additional boost limited by the
maximum boost defined by C
compensation when pin 7 is connected to pin 17. Pin 7 can
be connected to pin 12 to give the loudness compensated
volume characteristic as illustrated without the addition of
further external components. (Tone settings are for flat re-
sponse, C
tion to the loudness characteristic is possible by changing
the capacitors C
a resistor network between pins 7 and 12 for a different
threshold and slope.
SIGNAL HANDLING
The volume control function of the LM1036 is carried out in
two stages, controlled by the DC voltage on pin 12, to
improve signal handling capability and provide a reduction of
output noise level at reduced gain. The first stage is before
the tone control processing and provides an initial 15 dB of
gain reduction, so ensuring that the tone sections are not
overdriven by large input levels when operating with a low
volume setting. Any combination of tone and volume settings
may be used provided the output level does not exceed
1 Vrms, V
(
ceeds 1.6 Vrms, V
volume control on the input stages, the inputs may be oper-
ated with a lower overload margin than would otherwise be
acceptable, allowing a possible improvement in signal to
noise ratio.
<
−6 dB)the input stage will overload if the input level ex-
b
CC
and C
=12V (0.8 Vrms, V
b
and C
t
CC
as given in Application Circuit.) Modifica-
=12V (1.1 Vrms, V
t
for a different basic response or, by
b
and C
CC
=9V). At reduced gain
00514203
t
. There is no loudness
CC
=9V). As there is
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