TDC1000: What is the requirement for TRIGGER pulse?

John11513,

The minimum TRIGGER pulse width is dependent on the external clock since the external clock sets the sample rate.

For best practice, the minimum TRIGGER pulse width should be equal to (3*T0)+(2*T1) periods, since this is the time delta between the received trigger and the generated START pulse. This will ensure the TRIGGER pulse is sampled within the time required to generate the START pulse. See subset of TDC1000-Q1 datasheet section 8.4.5.2 TX/RX Measurement Sequencing and Timing:

During resynchronization, the trigger and START edges are aligned to the negative edge of the external clock.
The time between trigger and START is equal to 3 T0 periods plus 2 or 3 T1 periods, depending on the phase
between the received trigger pulse and the external clock. For example, if ƒCLKIN = 8 MHz and TX_FREQ_DIV =
0h2 (divide-by-8), the period T0 is 125 ns and the period T1 is 1 us, resulting in a time of 2.375 us or 3.375 us
between the received trigger signal and the generated START pulse.