Other Parts Discussed in Thread: LM5169, , LM5168
Tool/software:
Hi ,
I want to use LM5169 in my application, the application is an exact match to what I am looking for, 6V - 120V input, 5V, 0.6A max Load.
To try it our I ordered the LM5168PEVM eval board and ordered LM5169PDDAR separate units. I used the components value calculator available of the this part TI webpage. COT Type 3 , mode of operation and 100KHz switching frequency.
I replaced the original components on the eval board with below components
RT= 124kohm, 0.1W 1%
L0 = 150uH, 1.2 A Saturation current
Cin = 2 x 2uF 200V caps
Cout = 33uF, 20V
Ra = 442kohm, 0.1 W, 1%
Rfb2 = 143Kohm
The out voltage I see is 5.3V, with the load connected the value stays or is reduced a little , which is fine for me. But as soon as I take off the load the output slowly goes down to 0V and the output never comes up after reconnecting the load. I assume it goes to shutdown without load, but I dont see any such description in the datasheet.
However if I use the original LM5168PEVM eval board as is by replacing the Rfb2 =143Kohm resistor ( just to test with a 0.25A load, as LM5168 only supports 0.3A max). I dont see the same shutdown behavior.
Please help.
Regards
Abhi