- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384602 > LMC1992 (National Semiconductor Corporation) LMC1992 Digitally-Controlled Stereo Tone and Volume Circuit with Four-Channel Input-Selector PDF資料下載
參數(shù)資料
| 型號： | LMC1992 |
| 廠商： | National Semiconductor Corporation |
| 英文描述： | LMC1992 Digitally-Controlled Stereo Tone and Volume Circuit with Four-Channel Input-Selector |
| 中文描述： | LMC1992數(shù)控立體聲音調(diào)和音量電路四通道輸入選擇 |
| 文件頁數(shù)： | 8/14頁 |
| 文件大?。?/td> | 260K |
| 代理商： | LMC1992 |
Applications Information
(Continued)
TL/H/10789–19
FIGURE 3. System Block Diagram Showing Inclusion of DNR
é
Noise
Reduction (LM1894) and Equalizer (LMC835) (One Channel OnlyDLMC1992)
The SELECT OUT pins (8 and 22) enable greater system
design flexibility by providing a means to implement an ex-
ternal processing loop. This loop can be used for noise re-
duction circuits such as DNR (LM1894) or mulit-band graph-
ic equalizers (LMC835). It is important to ensure that if both
are used, the noise reduction circuitry precede the equaliza-
tion circuits. Failure to do so will result in improper operation
of the noise reduction circuits. The system shown in Figure
3 utilizes the external loop to include DNR and a multi-band
equalizer.
AUDIO MUTE
A mute function with attenuation of 100 dB is possible with
the volume control set to
b
80 dB and the INPUT select
code set to 01000XX0000 (open circuit).
TONE CONTROL RESPONSE
Base and treble tone controls are included in the LMC1992.
The tone controls use just two external capacitors for each
stereo channel. Each has a corner frequency determined by
the value of C2 and C3 (Figure 4) and internal resistors in
the feedback loop of the internal tone amplifier. The maxi-
mum amplitude boost or cut is determined by the data sent
to the LMC1992 (see Table I).
The typical tone control response shown in the Typical Per-
formance Curves were generated with C2
e
C3
e
0.0082
m
F and show the response for each step. When
modifying the tone control response it is important to note
that the ratio of C3 and C2 sets the mid-frequency gain.
Symmetrical tone response is achieved when C2
e
C3.
However, with C2
e
2(C3) and the tone controls set to
‘‘flat’’, the frequency response will be flat at 20 Hz and 20
kHz, and
a
6 dB at 1 kHz.
The frequency where a tone control begins to deviate from
a flat response will be referred to as the turn-over frequen-
cy. With C
e
C2
e
C3, the LMC1992’s treble turn-over
frequency is nominally
f
TT
e
1
2
q
C(14.2 k
X
)
The base turn-over frequency is nominally
f
BT
e
1
2
q
C(27.7 k
X
)
when maximum boost is chosen. The inflection points (the
frequencies where the boost or cut is within 3 dB of the final
value) are for treble and bass
f
TI
e
1
2
q
C(2.3 k
X
)
f
BI
e
1
2
q
C(164.1 k
X
)
8
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LMC1992CCN | LMC1992 Digitally-Controlled Stereo Tone and Volume Circuit with Four-Channel Input-Selector |
| LMC2001 | High Precision, 6MHz Rail-To-Rail Output Operational Amplifier |
| LMC2001ACM5 | High Precision, 6MHz Rail-To-Rail Output Operational Amplifier |
| LMC2001ACM5X | High Precision, 6MHz Rail-To-Rail Output Operational Amplifier |
| LMC2001AIM | High Precision, 6MHz Rail-To-Rail Output Operational Amplifier |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LMC1992CCN | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:LMC1992 Digitally-Controlled Stereo Tone and Volume Circuit with Four-Channel Input-Selector |
| LMC200 | 制造商:Black Box Corporation 功能描述:14 SLOT POWER CHASSIS W/1 POWE |
| LMC2001 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:High Precision, 6MHz Rail-To-Rail Output Operational Amplifier |
| LMC2001 WAF | 制造商:Texas Instruments 功能描述: |
| LMC2001ACM5 | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。