Other Parts Discussed in Thread: LM5116, LM61440, LM61460, LM76005
Hello,
I am working with the Evalboard of te LM5116. I modified some components to get the following specs:
Vin = 20V
Vout = 4.6V
Iload = 4A
To get this I changed R3 to 5600Ohms and R4 to 2000Ohms.
I also removed R12 and replace C14 with an 0Ohm resistor to disable the VCCX function.
Diode Emulation threshold is set to 0V via the Jumper 1.
Problem:
- with light load ther are heavy swings if the High-Side and Low-Side Mosfet are disabled. They do not weak over time. It looks like there is a Capacity from around 2.5nF. Can someone tell me how fix?
- When increas the load the LM5116 never goes in a CCM mode even if there is a load current of 2.5A. The Problem is show in the picture. After two High-Side pulses ther is a extrem long Low-Side puls. In this moment the Current of the Inductor (red waveform) goes to 0A. This is the point when Diode Emulation stops the Low-Side phase. But after this ther comes no High-Side phase in the elected Periode (f=250kHz). As result the frequency seems to be decreased and you can her an ringing from coil. Is this isue because of the current limiting or something else?
