APA2010B Datasheet, PDF (14/19 Pages) Anpec Electronics Coropration – 3W Mono Class-D Audio Power Amplifier

APA2010B
Application Information (Cont.)
Output LC Filter (Cont.)
Figure 3 is an example for adding the LC filter. It’s recom-
mended to eliminate the radiated emission or EMI when
the trace from amplifier to speaker is too long.
Layout Recommendation
9 X Φ 0.275mm
VON 47µH
1µF
47µH
4Ω
VOP
1µF
Figure 3. LC output filter
Figure 3’s low pass filter cut-off frequency is F_C
F_C(lowpass)
=
1
2π LC
(4)
Mixing Two Single-Ended Input Signals
C_{1 R1}
C₂ R₂
INP
C_{P RP}
INN
Figure 4. Mixing Two Single-Ended Input Signals
For mixing two Single-Ended (SE) input signals, please
refer to Figure 4. The gains of each input can be set
difference:
A _V (1)
=
2 × 150kΩ (or 125kΩ)
R₁
(5)
A _V (2)
=
2 × 150kΩ (or 125kΩ)
R₂
(6)
The corner frequency of each input high- pass-filter also
can be set by R₁&C₁, and R₂&C₂.
The non-inverting input’s resistor (R_P) and capacitor (C_P)
need to match the impedances of invert inputs.
C_P = C₁//C₂ = C₁ + C₂
(7)
R_P
=
R₁//R₂
=
R₁ × R₂
R₁ + R₂
(8)
0.5mm
Figure 5. WLCSP-9 land pattern recommendation
1. All components should be placed close to the
APA2010B. For example, the input resistor (R_in) should
be close to APA2010B’s input pins to avoid causing noise
coupling to APA2010B’s high impedance inputs; the
decoupling capacitor (C ) should be placed by the
s
APA2010B’s power pin to decouple the power rail noise.
2. The output traces should be short, wide (>50mil), and
symmetric.
3. The input trace should be short and symmetric.
4. The power trace width should greater than 50mil.
Copyright © ANPEC Electronics Corp.
14
Rev. A.1 - Mar., 2011
www.anpec.com.tw