SI5338 Datasheet, PDF (70/170 Pages) Silicon Laboratories – I2C-PROGRAMMABLE ANY-FREQUENCY, ANY-OUTPUT QUAD CLOCK GENERATOR

Si5338
Register 48.
Bit
D7
D6
D5
D4
D3
D2
D1
D0
Name PFD_EXTFB
PLL_KPHI[6:0]
Type
R/W
R/W
Reset value = xxxx xxxx
Bit
Name
Function
Selects PFD feedback input from internal (see Register 30[7:5]) or external source.
7
PFD_EXTFB 0: Internal feedback path
1: External feedback path (zero delay mode)
6:0
PLL_KPHI[6:0] ^{Sets the charge pump current for the PFD. Clockbuilder Desktop sets these values}
automatically. See AN411 for manual setting.
Register 49.
Bit
D7
Name FCAL_OVRD_EN
Type
R/W
D6
D5
D4
VCO_GAIN[2:0]
R/W
D3
D2
RSEL[1:0]
R/W
D1
D0
BWSEL[1:0]
R/W
Reset value = xxxx xxxx
Bit
Name
Function
FCAL Override Enable.
7
FCAL_OVRD_EN 0: Do not use FCAL value in registers 45,46,47
1: Use FCAL value in registers 45,46,47
Sets the VCO Gain.
6:4
VCO_GAIN[2:0] _{Clockbuilder Desktop sets these values automatically. See AN411 for manual set-}
ting.
Loop Filter Resistor Select.
3:2
RSEL[1:0]
Clockbuilder Desktop sets these values automatically. See AN411 for manual set-
ting.
Select the PLL Loopfilter.
1:0
BWSEL[1:0] _{Clockbuilder Desktop sets these values automatically. See AN411 for manual set-}
ting.
70
Rev. 0.6