CS4218 Datasheet, PDF (38/44 Pages) Cirrus Logic – 16-Bit Stereo Audio Codec

CS4218
Appendix A: CS4218 Compatibility with CS4216
IMPORTANT !!
If you are upgrading your design from the CS4216 to the CS4218, please make sure to read this entire
appendix. The CS4218 is pin compatible with the CS4216. This appendix provides a summary of
differences between the two codecs.
Pin Compatibility
The CS4218 is 100% pin compatible with the CS4216 when used in Serial Modes 3 and 4. The
differences are noted in the following paragraphs and tables.
The CS4218 integrates the 600-ohm series resistors for the LOUT and ROUT analog outputs on the IC
itself. For the CS4216, these resistors are not on-chip, and need to be provided externally.
The CS4218 pin named SMODE3 does not incorporate an on-chip pull-down resistor, as is provided
on the CS4216 Rev B and later. This pin must be tied high or low, or driven by control logic to the
desired state (depends on the serial mode used). If this pin is left floating, the codec will not work
correctly.
The CS4218 adds the pin named FILT. On the CS4216, this pin is a no connect. The FILT pin is only
used when employing the SM3 Multiplier sub-mode. When using this sub-mode, a 0.47uF capacitor
must be connected from the FILT pin to AGND. When not using the Multiplier sub-mode, this pin may
remain unconnected.
Serial Modes
The CS4218 supports Serial Modes 3 and 4 of the CS4216. In addition, the CS4218 provides the SM3
Multiplier sub-mode and Serial Mode 5, which are not provided on the CS4216.
The CS4218 does not support Serial Modes 1 and 2 of the CS4216.
Decimation and Interpolator Filter Responses
The CS4218 and CS4216 use different digital filters for the ADC decimators and DAC interpolators.
Tables A1 and A2 provide a comparison between each codec’s filter responses.
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