9 recommended operational sequences, 1 power-up, 2 power-down – Cirrus Logic CS4354 User Manual
Page 18: 3 sample rate change, 10 grounding and power supply arrangements, Cs4354
18
DS895F2
CS4354
4.9
Recommended Operational Sequences
The following sequences are recommended for minimal pops and clicks when transitioning between differ-
ent states of operation.
4.9.1
Power-Up
1.
Turn on power supplies.
2.
Wait for power supply voltages to stabilize.
3.
Apply the serial port clocks and data.
Provide the correct MCLK, LRCK, and SCLK (only in External Serial Clock Mode); please refer to
for common clock frequencies in the External Serial Clock Mode, and
supported modes in the Internal Serial Clock Mode. The sequence will complete and audio will be
output from the AOUTx pins within 50 ms after valid clocks are applied.
4.9.2
Power-Down
1.
Stop LRCK.
2.
Wait 5 ms.
3.
Stop MCLK without applying any glitched pulses to the MCLK pin.
A glitched pulse is any pulse that is shorter than the period defined by the minimum/maximum MCLK
signal duty cycle specification and the nominal frequency of the input MCLK signal. A transient may
occur on the analog outputs if the MCLK signal duty cycle specification is violated when the MCLK
signal is removed during normal operation; see
“Switching Specifications - Serial Audio Interface” on
4.
Turn off power supplies.
4.9.3
Sample Rate Change
1.
Stop LRCK.
2.
Wait 5 ms.
3.
Stop MCLK without applying any glitched pulses to the MCLK pin.
A glitched pulse is any pulse that is shorter than the period defined by the minimum/maximum MCLK
signal duty cycle specification and the nominal frequency of the input MCLK signal. A transient may
occur on the analog outputs if the MCLK signal duty cycle specification is violated when the MCLK
signal is removed during normal operation; see
“Switching Specifications - Serial Audio Interface” on
4.
Wait 2 ms.
This wait time is dictated by the discharge time of the recommended 2.2 µF FILT+ capacitor (see
“Typical Connection Diagram” on page 12
). Higher capacitance values will require longer wait times.
5.
Apply the serial port clocks and data.
Provide the correct MCLK, LRCK, and SCLK (only in External Serial Clock Mode); please refer to
for common clock frequencies in the External Serial Clock Mode, and
supported modes in the Internal Serial Clock Mode. The sequence will complete, and audio will be
output from the AOUTx pins within 50 ms after valid clocks are applied.
4.10
Grounding and Power Supply Arrangements
As with any high-resolution converter, the CS4354 requires careful attention to power supply and grounding
arrangements if its potential performance is to be realized. The