FAN7000D Datasheet, PDF (6/10 Pages) Fairchild Semiconductor – Low Power Amplifier

FAN7000D
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 FAN7000D, so that it makes FAN7000D 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
FAN7000D off.
3. AMP Block
This block diagram describes the AMP block with resistances, which control gain of FAN7000D.
The
gain
of
FAN7000D
is
V_{-----O----U----T-}
V_IN
≅
40
≅
32 [ dB ]
Output voltage of FAN7000D 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
VCC, the micro controller follow the sequence 2.
Mute on → Mute Operation → Mute off → Normal operation (Sequence 2)
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