Linear Chirp Specifications

Introduced in Digital Audio Acquisition and Generation Toolkit 2021 Q2

The following specifications apply to the Configure Chirp (N Ch) VI when configuring a linear chirp signal.

Start frequency range

0 to PDM rate/2

Stop frequency range

0 to PDM rate/2

Pre-chirp duration range

0 to 232 − 1 PDM samples, or approximately 23 minutes at PDM rate of 3.072 MHz

Chirp duration range

0 to 232 − 1 − Pre-chirp duration samples

The linear chirp rate range, in seconds, is defined by the following equation:

Linear chirp rate range = ± ( Stop freq - Start freq ) / Chirp duration

Refer to the following table for maximum chirp rates at different PDM rates.

Table 3. Maximum Linear Chirp Rate at Different PDM Rates
Maximum Linear Chirp Rate PDM Rate = 600 kHz PDM Rate = 800 kHz PDM Rate = 2.4 MHz PDM Rate = 3.072 MHz PDM Rate = 4.8 MHz
Range ±1.37 MHz/s ±2.44 MHz/s ±21.9 MHz/s ±35.9 MHz/s ±87.8 MHz/s
Minimum Time DC to PDM rate/2 7 ms 5 ms 2 ms 2 ms 1 ms