SNAS835 September 2022 LMK5B33414
PRODUCTION DATA
The runt pulse monitor uses a window detector to validate input clock pulses that arrive within the nominal clock period minus a programmable early window threshold (TEARLY). When an input pulse arrives after TEARLY, the pulse is considered valid and the runt pulse flag will be cleared. When an early or runt input pulse arrives before TEARLY, the monitor will set the flag immediately to disqualify the input.
Typically, TEARLY should be set lower than the input's shortest clock period (including cycle-to-cycle jitter). The early pulse monitor can act as a coarse frequency detector with faster detection than the ppm frequency detector. The early pulse monitor is supported for input frequencies between 2 kHz and fVCO/12 and should be disabled when outside of this range.
Users must enable missing clock detect in order to use early clock detect. Early clock detect cannot be enabled alone.