ZHCSO17C November 2019 – March 2022 LMX2694-SEP
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.
For example:
MASH_SEED = 1; PLL_DEN = 12; CHDIV = 16
If VCO_PHASE_SYNC = 0, Phase shift = 360 × (1 / 12) × (1 / 16) = 1.875 degrees.
If VCO_PHASE_SYNC = 1, Phase shift = 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.