JAJSJG0A May 2020 – January 2021 LMK5B12204
PRODUCTION DATA
The DPLL supports hitless switching through TI's proprietary phase cancellation scheme. When hitless switching is enabled, it will prevent a phase transient (phase hit) from propagating to the outputs when the two switched inputs have a fixed phase offset and are frequency-locked. The inputs are frequency-locked when they have same exact frequency (0-ppm offset), or have frequencies that are integer-related and can each be divided to a common frequency by integers. When hitless switching is disabled, a phase hit equal to the phase offset between the two inputs will be propagated to the output at a rate determined by the DPLL fastlock bandwidth. The hitless switching specifications (tHITLESS and fHITLESS) are valid for reference inputs with no wander. In the case where two inputs are switched but are not frequency-locked, the output smoothly transitions to the new frequency with reduced transient.