Applied Data Systems Bitsy Plus, Руководство пользователя

Страница: 34 / 68

Bitsy Plus User’s Manual
Page 24 ADS document # 110114-1001A
signals as shown at right. These capacitors block the DC component of the audio signal and
complete the conversion from differential to single-ended output drive. Leave the HP_IN signal
pulled high to enable headphone output.
Select blocking capacitor size based on the lowest frequency your application will need to play
out. Larger capacitors give improved bass response (lower frequency cutoff), but are physically
larger and cost more. The corner frequency for the low-pass filter created by the capacitor and the
headphone speaker is calculated as fo=1/(2
π
R
L
C). A 330 uF capacitor into a 32 ohm headphone
speaker will give a low cutoff frequency of 15 Hz. Use electrolytic capacitors rated for at least
6.3 V.
The pull-down resistors shown in the diagram drain any charge that builds up on the headphone
outputs when headphones are not connected. Use 1 k
Ω
resistors.