TS4984 Datasheet, PDF (20/29 Pages) STMicroelectronics – 2 x 1W Stereo audio power amplifier with active low standby mode

TS4984
Application Information
The following graph (Figure 65) shows an example of C_in and C_feed influence.
Figure 65: Frequency response gain versus C_in & C_feed
10
5
0
-5
-10
-15
-20
-25
10
Cfeed = 330pF
Cfeed = 680pF
Cin = 470nF ^{Cfeed = 2.2nF}
Cin = 22nF
Cin = 82nF
Rin = Rfeed = 22kΩ
Tamb = 25°C
100
1000
Frequency (Hz)
10000
4.4 Power dissipation and efficiency
Hypotheses:
l Voltage and current in the load are sinusoidal (V_out and I_out).
l Supply voltage is a pure DC source (V_cc).
Regarding the load we have:
V_out = V_PEAK sinωt (V)
and
I_out = -V---R-^o---^u-_L--^t--
(A)
and
P_out
=
V-----_{P----E----A----K---2----}
2R_L
(W)
Therefore, the average current delivered by the supply voltage is:
I_CCAVG = 2 ^V-----_π^P----R^E----^AL---^K--
(A)
The power delivered by the supply voltage is:
Psupply = V_CC ⋅ I_CCAVG
(W)
20/29