LM5160A: Isolated Fly-Buck in DCM mode?

Hi,Prithvi,

Thank you for the posting .I have found no switching IQ as below,  

 We have another LM5168/9 but current range is not same as LM5160A, please check if this works for you.

Elena

Hello Elena,

Can we please understand if PFM works with Fly Buck in LM5168? The current rating works.

Please let us know the total overall Iq with this solution.

Regards, Prithvi

The buck device have PFM mode but not recommend in Flybuck application, it is suggest FPWM,

Please check DS PFWM IQ ,

Elena.

Thanks, that's just for the IC. As mentioned in this user manual https://www.ti.com/lit/ug/snvu819/snvu819.pdf

The no load input current is 13 mA in table 2-1. Is there a solution to get this value to around 1mA for an isolated 5V supply?

Lower the frequency could be one way to improve efficiency at light load.. frequency range from 100~1000Khz, 

Elena

The 13mA number is with a 750 kHz setting. So say if we make the switching freq of 100 kHz, the input current reduces to 2-3mA?

In any case, any other methodology to get low Iq isolated 5V supply? Thanks

It. may not achieve as lower as PFM mode for flybuck, I have found a similar answer here, https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1160183/lm5161-fly-buck-converter-with-very-low-iq/4362085?tisearch=e2e-sitesearch&keymatch=low%25252525252520iq%25252525252520isolate#4362085

and for 100V rating buck ,LM5168/9 is what we have .

Thank you. For a lower voltage rating? As I asked, I am looking for a 12V to 5V or 5V to 5V isolated power supply,

WVB support 36Vto 120V device, if you also accept lower voltage, please also check with MV product, you can submit another ticket choose MV.

I have a low IQ  LMR43610 FPWM mode, but you need to confirm the current is good for you output .

Elena

Thanks Elena.

My requirement is 12V or 5V to 5V, Iout of 100mA with low Iq. Please suggest which part I can use for raising a new ticket?

Since flybuck should use PFWM ,so the efficiency is very low at light load, choose a low IQ LMR43610 mya help to improve .

i have found https://e2e.ti.com/support/power-management-group/power-management---internal/f/power-management---internal-forum/1123522/tps54202h-flybuck-design-review-request/4176370?tisearch=e2e-sitesearch&keymatch=low%25252520iq%25252520flybuck#4176370

you can also check it for 12Vin use. 

Elena

Hello, I think its an internal forum link and not accessible. Can you please let me know what was the input current for the circuit in the link you posted?