LTC2320 SPI delay estimation

[nkrackow]

Delays (typ, max in ns) in the SPI path:

• MAX9130: 1.8, 3.0
• DS90CV: 1.1, 1.5
• LTC2320: na, 5.5
  • This is more difficult to say from the datasheet. I added t_DSCKCLKOUT to t_HSDO to get 5.5 ns max.
• Propagation delays: 10, 20
  • Assume 1, 2 m cable+traces from Driver to the Headboard and 2/3 c signal speed: 4 / ( c * 0.66)
• STM32H7 QSPI setup time: na, 2

Typ delay: 20.4 ns --> 24.5 MHz SPI clock Max delay: 32 ns --> 15.6 MHz SPI clock

Note: Factor of 1/2 since we are looking at the time from a falling clock edge to data latching at a rising clock edge.