LA4440 查看數據表（PDF） - SANYO -> Panasonic
零件编号
产品描述 (功能)
生产厂家
LA4440 Datasheet PDF : 13 Pages
| |||
Voltage Gain Adjust at Stereo Mode
LA4440
RNF=50Ω (typ), Rf=20kΩ (typ)
At RNF’=0 (recommended VG)
VG=20log
VG
RNF
(dB)
In case of using RNF’
Rf
VG=20log RNF+RNF’ (dB)
Voltage Gain Adjust at Bridge Amplifier Mode (No. 1)
Voltage Gain Adjust at Bridge Amplifier Mode (No. 2)
· The bridge amplifier configuration is as shown left, in
which ch1 and ch2 operate as noninverting amplifier
and inverting amplifier respectively.
The output of the noninverting amplifier divided by
resistors R3, R4 is applied, as input, to the inverting
amplifier.
Since attenuation (R4/R3) of the non-inverting amplifier
output and amplification factor (Rf/R4+RNF) of the
inverting amplifier are fixed to be the same, signals of
the same level and 180° out of phase with each other
can be obtained at output pins (12) and (10). The total
voltage gain is apparently higher than that of the
noninverting amplifier by 6dB and is approximately
calculated by the following formula.
VG=20log
Rf
RNF
+ 6dB
In case of reducing the voltage gain, RNF’ is connected
to the noninverting amplifier side only and the following
formula is used.
VG=20log
Rf
RNF+RNF’
+ 6dB
VG=20log
Rf
RNF+RNF’
(dB)
2
where (RNF+RNF’) << R5
From this formula, it is seen that connecting RNF’
causes the voltage gain to be reduced at the modes of
both stereo amplifier and bridge amplifier.
No.750–5/13
Share Link: 