ZHCSG17B January 2017 – July 2019 LMK04610
PRODUCTION DATA.
PLL2 design is based on semi-digital PLL architecture where the proportional and integral parts are separated from each other. Proportional gain and integral gain can be individually programmed by the user to define the bandwidth and noise transfer characteristics of the PLL2 in combination with the input modes.
PARAMETER | REGISTER | DESCRIPTION | MIN | TYP | MAX | UNIT |
---|---|---|---|---|---|---|
PLL2_PROP_SET | 0x72 | Proportional gain setting | 0 | 63 | ||
PLL2_CPROP | 0x151 | Proportional cap setting | 3 | 5.4 | pF | |
PLL2_INTG | 0x80 | Integral gain setting | 0 | 31 | ||
PLL2_RFILT | 0x151 | 3rd order filter resistor selection | 4.7 | 9.2 | kΩ | |
PLL2_CFILT | 0x153 | 3rd order filter capacitor selection | 0 | 15 | 124 | pF |
The proportional gain can be changed using PLL2_PROP and PLL2_CPROP. The difference between the two modes is, PLL2_PROP controls the proportional charge pump current to define the gain and PLL2_CPROP controls the on-chip capacitor used in active damping to define the proportional gain. Higher values of PLL2_PROP result in higher proportional gain and Higher PLL2_CPROP values result in lower proportional gain.