MAX9701 MAXIM [Maxim Integrated Products], MAX9701 Datasheet - Page 16

• Manufacturer Part Number: MAX9701
• Description: 1.3W, Filterless, Stereo Class D Audio Power Amplifier
• Manufacturer: MAXIM [Maxim Integrated Products]

Low frequencies are summed through a two-pole low-
pass filter and sent to the MAX9700 mono speaker
amplifier. The passband gain of the lowpass filter is
unity for in-phase stereo signals,
where R1 = R2 and R3 = R1//R2. The cutoff frequency
of the lowpass filter is set by the following equation:
Proper layout and grounding are essential for optimum
performance. Use large traces for the power-supply
inputs and amplifier outputs to minimize losses due to
parasitic trace resistance. Large traces also aid in moving
heat away from the package. Proper grounding improves
audio performance, minimizes crosstalk between chan-
nels, and prevents any switching noise from coupling into
the audio signal. Connect PGND and GND together at a
single point on the PC board. Route all traces that carry
switching transients away from GND and the traces/com-
ponents in the audio signal path.
1.3W, Filterless, Stereo Class D Audio
Power Amplifier
16
Supply Bypassing, Layout, and Grounding
______________________________________________________________________________________
f
=
2
1
π
×
C
− ×
1
2
×
R
1
C
R
2
3
×
1
R
3
×
R
4
Bypass V
PGND. Place the bypass capacitors as close to the
MAX9701 as possible. Use large, low-resistance output
traces. Current drawn from the outputs increases as load
impedance decreases. High-output trace resistance
decreases the power delivered to the load. Large output,
supply, and GND traces allow more heat to move from
the MAX9701 to the air, decreasing the thermal imped-
ance of the circuit.
The MAX9701 thin QFN-EP package features an
exposed thermal pad on its underside. This pad lowers
the package’s thermal impedance by providing a
direct heat conduction path from the die to the printed
circuit board. Connect the exposed thermal pad to the
GND plane.
For the latest application details on UCSP construction,
dimensions, tape carrier information, printed circuit board
techniques, bump-pad layout, and recommended reflow
temperature profile as well as the latest information on
reliability testing results, refer to Application Note:
UCSP—A Wafer-Level Chip-Scale Package available on
Maxim’s website at www.maxim-ic.com/ucsp.
UCSP Applications Information
DD
with 10µF to GND and PV
DD
with 0.1µF to