Stereo Headphone Amplifier
(Preliminary)
CO8301
Application Information
1. PS Block
This block diagram describes the power save switch circuits.
The drive block is controlled by PS pin, which can be derived from micro controller.
It controls bias of the internal circuits of CO8301, so that it makes CO8301 operate when input voltage level reaches
high level.
2. Mute Block
The block diagram describes the mute on switch circuits.
The drive block is controlled by MUTE pin, which can be derived from micro controller.
When the pin of mute turns on, it makes reference voltage of internal circuits approximately 0V, so that it keeps the device of
CO8301 off.
3. AMP Block
This block diagram describes the AMP block with resistances, which control gain of CO8301.
The gain of CO8301 is
V
OUT
--------------
≅
40
≅
32
[
dB
]
V
IN
Output voltage of CO8301 can be 40 times as much as input voltage, so it eliminates the number of external circuits and
offers headphone input.
4. Popping Noise Reduction
If PS pin (Pin1 , Power save switch) connect the micro controller, the micro controller must follow the same sequence 1 in
order to reduce popping noise on mute mode.
PS on
→
Mute on
→
PS off
→
Mute operation
→
PS on
→
Mute off
→
Normal operation (Sequence 1) If PS connect
V
CC
, the micro controller follow the sequence 2.
Mute on
→
Mute Operation
→
Mute off
→
Normal operation (Sequence 2)
* All specs and applications shown above subject to change without prior notice.
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Page 6 of 9
Rev 0.1 Mar. 25, 2003
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CERAMATE [ CERAMATE TECHNICAL ]
