TDA7576B データシートの表示（PDF） - STMicroelectronics
部品番号
コンポーネント説明
メーカー
TDA7576B Datasheet PDF : 17 Pages
| |||
TDA7576B
4
Principle of operation
Principle of operation
The TDA7576B is an innovative stereo audio amplifier meant for 24 V battery vehicles. The
amplifier works in a single-ended configuration without the large decoupling capacitors on
the outputs normally required by the s.e. topology. Its principle of operation is depicted in
Figure 11.
Figure 11. Amplifier structure
6REF
)N
#HANNEL INVERTING
6REF (6CC
/UT
)O
362
(6CC
)(6CC
)O
)N
#HANNEL NONINVERTING
6REF
6REF
/UT
(6CC
'!0'03
Channel 1 is electrically inverting its input signal whereas channel 2 is not; if the speakers
are connected with the positive pole of speaker 2 connected to Out2 and the negative pole
of speaker 1 connected to Out1, then the two channels both behave as non-inverting.
Speaker 1 and speaker 2 have one terminal in common and further connected to a half Vcc
(HVCC) buffer.
If the signals at In1 and In2 are identical, then the voltage at Out1 and Out2 is identical in
magnitude but inverted (Out1 = -Out2), and the current flowing through speaker 1 is all
coming from speaker 2, with no current going into the HVCC buffer. If the signal at In1 is not
identical to that at In2, then the signal at the two outputs will not be identical either, and
some current will flow into or out of the HVCC buffer, keeping the voltage at HVCC constant.
This structure allows therefore the amplifier to operate in a single-ended configuration with
no need for decoupling capacitors.
Mathematically this can be expressed as:
VL1 = -G * Vin1
VL2 = +G * Vin2
IHVCC = Io1 + Io2 = VL1/RL + VL2/RL = G (Vin2 - Vin1) / RL
Doc ID 023511 Rev 3
11/17
Share Link: 