![background image](http://html.mh-extra.com/html/national-semiconductor/lm4681/lm4681_user-manual_710372010.webp)
Typical Demonstration Board Audio Performance (C-CUPL Mode)
Typical Class D power amplifier and Class AB headphone amplifier THD+N versus Output Power performance curves at V
DD
=
12V, are shown in Figure 9 and Figure 10, respectively. Typical Class D power amplifier and Class AB headphone amplifier mode
THD+N versus Frequency performance curves at V
DD
= 12V are shown in Figure 11 and Figure 12, respectively.
20195914
R
L
= 8
Ω
, f
IN
= 1kHz, V
DD
= 12V
Figure 9. Class D Amplifier THD+N vs Output Power
20195915
R
L
= 32
Ω
, f
IN
= 1kHz, V
DD
= 12V
Figure 10. Class AB Headphone Amplifier
THD+N vs Output Power
20195916
R
L
= 8
Ω
, f
IN
= 1kHz
V
DD
= 12V, P
O
= 1W
Figure 11. Class D Amplifier HD+N vs Frequency
20195917
R
L
= 32
Ω
, f
IN
= 1kHz
V
DD
= 12V, P
O
= 20mW
Figure 12. Class AB Headphone Amplifier
THD+N vs Frequency
AN-1488
www.national.com
10