10.1 Layout Guidelines
The following steps are to be used as a reference to ensure the device is stable and maintains proper LED current regulation across its intended operating voltage and current range.
- Place CIN on the top layer (same layer as the LM36011) and as close as possible to the device. Connecting the input capacitor through short, wide traces to both the IN and GND pins reduces the inductive voltage spikes that occur during switching which can corrupt the VIN line.
- Terminate the flash LED cathode directly to the GND pin of the LM36011. If possible, route the LED return with a dedicated path so as to keep the high amplitude LED current out of the GND plane. For a flash LED that is routed relatively far away from the LM36011, a good approach is to sandwich the forward and return current paths over the top of each other on two layers. This helps reduce the inductance of the LED current path.