lm4663 National Semiconductor Corporation, lm4663 Datasheet - Page 7

• Manufacturer Part Number: lm4663
• Description: 2 Watt Stereo Class D Audio Power Amplifier With Stereo Headphone Amplifier
• Manufacturer: National Semiconductor Corporation

Applications Information
flow through the amplifier. Once V
FIGURE 2. At power-up, the LP3740 forces the LM4663 into shutdown, which prevents abnormal quiescent current
Class AB
Class D
HP Jack
FIGURE 3. Recommended PC board layout:
TABLE 3. These are the functions selected by the jumpers on the recommended PC board. (Continued)
Component side silkscreen
Shorting activates the headphone amplifier and deactivates the Class D amplifier. Class D and
HP jack jumpers are open
Shorting activates the Class D amplifier and deactivates the headphone amplifier. Class AB and
HP jack jumpers are open
Shorting allows the act of plugging in headphones to activate the headphone amplifier and
deactivate the Class D amplifier. Removing headphones restores Class D amplifier operation and
deactivates the headphone amplifier. Class AB and Class D jumpers are open. (Requires the
use of a headphone jack like that shown in Figure 1.)
CC
rises above 4V and after a 200ms delay set by C1, normal amplifier operation is
(Continued)
10126905
restored.
7
FIGURE 4. Recommended PC board layout:
Component side layout
10126904
10126906
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