How to implement the N-1 function for more than 2x TLD509xEP?
In order to implement the N-1 function without a microcontroller you need to place additional digital gates.
Here is an example for the TLD5098EP. For the TLD5097EP, exchange ST pin with PWMO pin.
In the datasheet the fault behavior of TLD5098EP is well described in the Diagnosis truth table (table 10). This table shows that the faults are signaled with a low digital signal at PWMO when PWMI digital input is high
This fault status for an LED driver with TLD5098EP is recognized with an AND gate where the PWMO is inverted.
If you have more than one LED driver, you can detect that a driver is in fault mode just using an OR gate fed by the LED driver fault signal.
Then you can use an SR latch to store the status and switch off all the DC-DC.
You need a RESET signal to start-up the LED drivers again.
https://www.infineon.com/cms/en/about-infineon/company/contacts/support/images/N-1_fault.png Here is a sketch of the circuit for a 2 LED driver system.