BIAS Capacitor

power-supply rejection ratio by reducing power supply

and other noise sources at the common-mode bias node.

bias waveform for the speaker amplifiers. Bypass BIAS

external loads to BIAS.

Supply Bypassing

Proper power-supply bypassing ensures low-noise,

low-distortion performance. Connect a 1µF ceramic

capacitance as required by the application. Connect

the bypass capacitor as close to the device as possible.

Layout and Grounding

Proper PC board layout and grounding is essential for

optimizing 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 and prevents

digital switching noise from coupling into the audio signal.

The MAX9716/MAX9717 TDFN and µMAX packages

feature exposed thermal pads on their undersides. This

pad lowers the thermal resistance of the package by

providing a direct-heat conduction path from the die to

the printed circuit board. Connect the exposed pad to

the ground plane using multiple vias, if required.

Low-Cost, Mono, 1.4W BTL Audio Power

Amplifiers

12

______________________________________________________________________________________

CLICKLESS/POPLESS

SHUTDOWN

CONTROL

BIAS

IN+

IN-

OUT+

OUT-

SHDN

GND

MAX9716

20k

Ω

20k

Ω

20k

Ω

0.33

µF

AUDIO

INPUT

20k

Ω

0.33

µF

AUDIO

INPUT

220pF

220pF

20k

Ω

20k

Ω

VALUES SHOWN FOR 0dB GAIN.

OFF

ON

Figure 4. MAX9716 Differential Input