Stereo 3W Audio Power Amplifiers with Headphone Drive and Input Mux
Table 1b. MAX9778 HPS Setting
INPUTS |
| MODE | GAIN PATH* | |
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HPS_EN |
| HPS | ||
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| ||
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|
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|
0 |
| X | BTL | A or B |
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|
|
|
|
1 |
| 0 | BTL | A or B |
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|
|
|
|
1 |
| 1 | SE | A or B |
*Note:
A or
Headphone Sense Input (HPS)
With headphone sense enabled, a voltage on HPS less than 0.7 x VDD sets the device to speaker mode. A volt- age greater than 0.9 x VDD disables the inverting bridge amplifier
For automatic headphone detection, enable headphone sense and connect HPS to the control pin of a
|
| VDD | MAX9777/MAX9778 | |
|
| R1 | ||
MAX9777 | R3 | 680kΩ | ||
| ||||
MAX9778 | 47kΩ |
| ||
HPS |
|
| ||
OUTL+ |
|
| ||
OUTR+ |
|
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| R2 | R2 | ||
| 10kΩ | 10kΩ | ||
Figure 2. HPS Configuration Circuit |
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device. The digital section of the MAX9777 remains | ||||
active when the device is shut down through the inter- | ||||
face. All devices feature a | ||||
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MUTE
The MAX9777/MAX9778 feature a mute mode. When the device is muted, the input is disconnected from the amplifiers. MUTE does not shut down the device.
MAX9777 MUTE The MAX9777 MUTE mode is selected by writing to the MUTE register (see the Mute Register section). The left and right channels can be independently muted.
MAX9778 MUTE The MAX9778 features an
Shutdown
The MAX9777/MAX9778 feature a 10µA,
MAX9777 Software Shutdown A
Click-and-Pop Suppression
The MAX9777/MAX9778 feature Maxim’s comprehen- sive
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