Winsu
Full Member level 3
Hi All,
I have designed a circuit using the ZLED7730-ZI1R to power up a few LEDs. The string current is to be meant 0.35A but I had to limit the PSU as it would draw whatever figure I allow on the PSU. I have used normal diodes as LEDs are very expensive ( this is the diode I have used: CD123D-B140LR ).
The dim 1 and dime 2 pins are to set a dim profile. I initially set the DIM to GND, but as it wasn't working and left DIM 1 floating ( it would mean 100% always).
I don't know why it is not working. I set the PSU ay 24V and 0.4A and the voltage drop to 4V and I draws the 0.4A. There are 3.5V dropping accros the diodes and 0.5V between Lx and GND. For some reason he internal mosfet is constantly on and it is not regulating at all. Below is the schematic. Any help would be very useful, thanks.
I have designed a circuit using the ZLED7730-ZI1R to power up a few LEDs. The string current is to be meant 0.35A but I had to limit the PSU as it would draw whatever figure I allow on the PSU. I have used normal diodes as LEDs are very expensive ( this is the diode I have used: CD123D-B140LR ).
The dim 1 and dime 2 pins are to set a dim profile. I initially set the DIM to GND, but as it wasn't working and left DIM 1 floating ( it would mean 100% always).
I don't know why it is not working. I set the PSU ay 24V and 0.4A and the voltage drop to 4V and I draws the 0.4A. There are 3.5V dropping accros the diodes and 0.5V between Lx and GND. For some reason he internal mosfet is constantly on and it is not regulating at all. Below is the schematic. Any help would be very useful, thanks.