ZHCSIC4C June 2018 – November 2018 LMX2615-SP
PRODUCTION DATA.
The MASH_SEED word can use the sigma-delta modulator to shift output signal phase with respect to the input reference. If a SYNC pulse is sent (software or pin) or the MASH is reset with MASH_RST_N, then this phase shift is from the initial phase of zero. If the MASH_SEED word is written to, then this phase is added. The phase shift is calculated as below.
Example:
Mash seed = 1
Denominator = 12
Channel divider = 16
Phase shift ( VCO_PHASE_SYNC=0) = 360 × (1/12) × (1/16) = 1.875 degrees
Phase Shift (VCO_PHASE_SYNC=1) = 360 × (1/12) × (4/16) = 7.5 degrees
There are several considerations when using MASH_SEED
When using MASH_SEED in the case where IncludedDivide>1, there are several additional considerations in order to get the phase shift to be monotonically increasing with MASH_SEED.