wm9081 Wolfson Microelectronics plc, wm9081 Datasheet - Page 72

• Manufacturer Part Number: wm9081
• Description: Mono Dac With 2.6w Class Ab/d Speaker Driver, Dynamic Range Controller And Retune Mobile Parametric Equalizer
• Manufacturer: Wolfson Microelectronics plc

WM9081
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Sett FLL_GAIN to the recommended setting:
FLL_GAIN = 0000 (multiply by 1)
Set FLL_OUTDIV for the required output frequency as shown in Table 40:-
F
Set FLL_FRATIO for the given reference frequency as shown in Table 41:
F
Calculate F
F
Calculate N.K as given by N.K = F
N.K = 98.304 / (1 x 12) = 8.192
Determine FLL_N and FLL_K from the integer and fractional portions of N.K:-
FLL_N is 8. FLL_K is 0.192
Confirm that N.K is a fractional quantity and set FLL_FRAC:
N.K is fractional. Set FLL_FRAC = 1.
Note that, if N.K is an integer, then an alternative value of FLL_FRATIO should be
selected in order to produce a fractional value of N.K.
OUT
REF
VCO
= 12MHz, therefore FLL_FRATIO = 0h (divide by 1)
= 12.288 MHz, therefore FLL_OUTDIV = 2h (divide by 8)
= 12.288 x 8 = 98.304MHz
VCO
as given by F
VCO
= F
VCO
OUT
/ (FLL_FRATIO x F
x FLL_OUTDIV:-
REF
):
PP, Rev 3.0, April 2009
Pre-Production
72