max98089 Maxim Integrated Products, Inc., max98089 Datasheet - Page 108

• Manufacturer Part Number: max98089
• Description: Low-power, Stereo Audio Codec With Flexsound Technology
• Manufacturer: Maxim Integrated Products, Inc.

Figure 29. Class H Operation
Figure 28. Traditional Amplifier Output vs. DirectDrive Output
DirectDrive AMPLIFIER BIASING SCHEME
CONVENTIONAL AMPLIFIER BIASING SCHEME
V
V
-0.9V
-1.8V
TH_H
TH_L
1.8V
0.9V
HPVDD
HPVSS
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32ms
32ms
Low-Power, Stereo Audio Codec
OUTPUT
VOLTAGE
GND
+V
GND
-V
(V
V
V
DD
DD
SS
DD
DD
/2
)
with FlexSound Technology
A Class H amplifier uses a Class AB output stage with
power supplies that are modulated by the output signal.
In the case of the ICs, two nominal power-supply differ-
entials of 1.8V (+0.9V to -0.9V) and 3.6V (+1.8V to -1.8V)
are available from the charge pump. Figure 29 shows the
operation of the output-voltage-dependent power supply.
HPSNS senses the ground return for the headphone
load. For optimal performance, connect HPSNS to the
ground pole of the jack through an isolated trace, as
shown in Figure 30. If HPSNS is not used, connect to the
analog ground plane.
Figure 30. HPSNS configurations
CONFIGURATION FOR OPTIMAL PERFORMANCE
CONFIGURATION FOR WHEN NOT USING HPSNS
HPSNS
HPSNS
HPR
HPR
HPL
HPL
Headphone Ground Sense (HPSNS)
MAX98089
Class H Operation
HEADPHONE
HEADPHONE
JACK
JACK