max9773etgt Maxim Integrated Products, Inc., max9773etgt Datasheet - Page 16

• Manufacturer Part Number: max9773etgt
• Description: Max9773 1.8w, Filterless, Ultra-low Emi, Stereo Class D Audio Power Amplifier
• Manufacturer: Maxim Integrated Products, Inc.

The MAX9773 does not require an output filter. The
device passes FCC emissions standards with 6in of
unshielded speaker cables. However, output filtering
can be used if a design is failing radiated emissions due
to board layout or cable length, or if the circuit is near
EMI-sensitive devices. Use a ferrite bead filter when
radiated frequencies above 10MHz are of concern. Use
an LC filter or a common-mode choke when radiated
emissions below 10MHz are of concern, or when long
leads (>6in) connect the amplifier to the speaker.
1.8W, Filterless, Ultra-Low EMI,
Stereo Class D Audio Power Amplifier
Figure 8. 2.1 Channel Application Circuit
16
______________________________________________________________________________________
NOTE: VALUES SHOWN ARE FOR A LOWPASS CUTOFF OF 2Hz AND A BASS GAIN OF -1V/V.
FFM MODE WITH f
OSC
= 1100kHz.
20kΩ
20kΩ
R1
R2
2200pF
2200pF
2200pF
2200pF
Output Filter
C
C
C
C
IN
IN
IN
IN
C1
0.01µF
INL+
INR+
INL-
INR-
SYNC
39kΩ
R4
1.25V
MAX9773
5V
SYNC_OUT
10kΩ
The typical 2.1 channel application circuit (Figure 8)
shows the MAX9773 configured as a mid/high-frequency
amplifier and the MAX9705 configured as a mono bass
amplifier. Input capacitors (C
frequency according to the following equation:
where R
MAX9773. The 10µF capacitors on the output of the
MAX9773 ensure a two-pole highpass filter.
R3
OUTR+
OUTL+
OUTR-
OUTL-
MAX4238
1nF
C2
10µF
10µF
IN
is the typical input resistance of the
8Ω
8Ω
1µF
1µF
f
=
2π
SYNC
IN+
IN-
2.1 Channel Configuration
×
MAX9705
R
IN
V
1
5V
DD
IN
×
) set the highpass cutoff
C
OUT+
OUT-
IN
4Ω