Cirrus Logic CDB44800 - Manual (Page 5)

CDB44800
DS632DB2 5
The output snubbing capacitors, C43-C56, used to shape the switching PWM output edges,
should be 560 pF, C0G (NPO), with a voltage rating above the VP voltage. This board is pop-
ulated with KEMET C0805C561K5GAC05R62F parts.
The output low-pass filter inductors, L1-L12, used to filter high frequency content from the
speakers, should be chosen so that their saturation current rating is above that of the maxi-
mum output current. This board is populated with TRANSTEK MAGNETICS TMP50627CT
and TMP50626CT parts.
The output low-pass filter capacitors, C13-C16, C18, C19, C21-C24, C26, and C27, used to
filter high frequency content from the speakers, should be chosen to have a dielectric of met-
allized film, with a voltage rating above the VP voltage. This board is populated with PANA-
SONIC ECQV1H474JL and ECQV1H105JL parts.
The half-bridge channels output high-pass filter capacitors, C17, C20, C25, and C28, used
to filter DC frequency content from the speakers, should have a ripple current rating above
the maximum peak output current and have a voltage rating above the maximum peak output
voltage. This board is populated with PANASONIC ECA1HM102 parts. The capacitance val-
ue determines the cutoff frequency of the high-pass filter. The cutoff frequency (-3 dB point)
on the board has been set for 26 Hz when used with a 6
Ω load.
The VP power supply bulk decoupling capacitors, C29-C32 and C57-C60 should be chosen
to have a voltage rating above the VP voltage. The lower the capacitor’s ESR rating at the
working frequency, the better the noise attenuation. Low ESR decoupling capacitors will of-
fer lower output speaker noise than high ESR capacitors. This board is populated with
NICHICON UPW1J102MHH parts.
The Zoble filter network resistors, R1-R12, used to impedance match the speaker, should be
chosen to have a power handling according to the following equation: P = C * V² * f. For this
board, C = 0.22
µF, f = 20 kHz, and V = the RMS full-scale output voltage. This board is pop-
ulated with 1 W DALE CRCW251222R1F parts.