CYW4343X
Whenever possible, the preferred approach is to use a precision external 32.768 kHz clock that meets the requirements listed in
Table 4 on page 24.
Note: The CYW4343X will auto-detect the LPO clock. If it senses a clock on the EXT_SLEEP_CLK pin, it will use that clock. If it
doesn't sense a clock, it will use its own internal LPO.
■
To use the internal LPO: Tie EXT_SLEEP_CLK to ground. Do not leave this pin floating.
To use an external LPO: Connect the external 32.768 kHz clock to EXT_SLEEP_CLK.
■
Table 4. External 32.768 kHz Sleep-Clock Specifications
Parameter
LPO Clock
Units
Nominal input frequency
Frequency accuracy
Duty cycle
32.768
±200
kHz
ppm
%
30–70
Input signal amplitude
Signal type
200–3300
mV, p-p
–
Square wave or sine wave
Input impedancea
>100
<5
kΩ
pF
Clock jitter
a. When power is applied or switched off.
<10,000
ppm
Document No. 002-14797 Rev. *H
Page 24 of 128
CYPRESS [ CYPRESS ]
