Texas Instruments TPA721, Руководство пользователя

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Using The TPA721 MSOP EVM With the Plug-N-Play Evaluation Platform
3-8 Details
Figure 3–6. Mute/Mode and Polarity Control
J10
Headphone
Jack
R3
240
Ω
R4
1 k
Ω
R5
1 k
Ω
JP8 JP6
U3, U4
Power
Amplifiers
Lo
Hi
Polarity
Mode
Mute
VDD
SPK
(U2–U4)
3.3.3.2 Mute/Mode Select (JP6)
A 3-pin jumper header (JP6) on the platform, functioning as a SPDT switch,
routes the control signal from the headphone jack to either the mute control
input pin or the mode control input pin of the evaluation module.
J
To mute the TPA721 MSOP amplifier module using the control signal
from the platform headphone jack, jumper JP6 to MUTE.
J
To not affect the TPA721 amplifier when a plug is inserted into the
headphone jack, jumper JP6 to Mode or leave JP6 unjumpered.
3.3.3.3 Mute/Mode Polarity Select (JP8)
A second 3-pin jumper header (JP8) on the platform selects the control signal
polarity by connecting either the active-high or the active-low line from the
headphone jack to jumper JP6.
-
When JP6 is set to mute, use the following JP8 settings for the TPA721:
J
To mute the TPA721 MSOP amplifier module when a plug is inserted
into the headphone jack, jumper JP8 to Hi (this is the typical setting).
J
To mute the TPA721 MSOP amplifier module until a plug is inserted
into the headphone jack, jumper JP8 to Lo.
-
When JP6 is set to mode, the TPA721 amplifier is unaffected by the inser-
tion of the headphone plug.