Cirrus Logic CS4365 - Manual (Page 28)

28 DS670F2
CS4365
4.10 Analog Output and Filtering
The application note “Design Notes for a 2-Pole Filter with Differential Input” discusses the second-order
Butterworth filter and differential to single-ended converter which was implemented on the CS4365 evalua-
tion board, CDB4365, as seen in
Figure 20 . The CS4365 does not include phase or amplitude compensa-
tion for an external filter. Therefore, the DAC system phase and amplitude response will be dependent on
the external analog circuitry. The off-chip filter has been designed to attenuate the typical full-scale output
level to below 2 Vrms.
Figure 19 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 19. Full-Scale Output
Figure 20. Recommended Output Filter