Cirrus Logic CS4385A - Manual (Page 29)

DS837F2 29
CS4385A
4.10 Analog Output and Filtering
Cirrus Logic application note AN55, “Design Notes for a 2-Pole Filter with Differential Input,” discusses the
second-order Butterworth filter and differential-to-single-ended converter shown in
Figure 23 . The CS4385A
does not include phase or amplitude compensation for an external filter. Therefore, the DAC system phase
and amplitude response are dependent on the external analog circuitry. The off-chip filter has been de-
signed to attenuate the typical full-scale output level to below 2 Vrms.
Figure 22 shows how the full-scale differential analog output level specification is derived.
AOUT+
AOUT-
Full-Scale Output Level= (AOUT+) - (AOUT-)= 6.6 Vpp
4.15 V
2.5 V
0.85 V
4.15 V
2.5 V
0.85 V
Figure 22. Full-Scale Output
Figure 23. Recommended Output Filter