Other Parts Discussed in Thread: ISO7740, ISO7742
Hello,
I want to isolate SPI bus with 4 chip selects. (MOSI,MISO, CLK and 4 Chipselects). I use ISO7342 & ISO7340 for this purpose. MOSI, MISO and CLK lines are connected to 4 slaves on SPI bus. Only one chipselect is active at a time. Slave digital input capacitance is 6pF according to slave datasheet. I know current capability of the isolators are +-4mA. I want to make sure isolators are going to be enough to handle 4 slaves. SPI frequency is going to be around 1 MHz. Can you help me confirm that i wont have problems with 4 SPI slaves?
Spi lines will have 150 ohm serial resistors and clock freq will be 1 MHz.
Slaves and the isolators are on the same board and the trace length of the furthest slave is about 5 inches.
clock frequency is low, trace capacitance due to routing is low, I have serial resistors on signals, do i need a spi buffer ?
