Vref of boost , current limit of boost convertor

[NoahXu]

what is the voltage value of vref of boost convertor of S12ZVML64?

what is the unit of boost convertor current limit? mA or A? hwow to set by write register value?

[danielmartynek]

Hi @NoahXu,

The Vref does not matter, there is the VSUP boost turn on/off point specified in the RM.

Refer to AN5207 Hardware Design Guidelines for S12ZVM

https://www.nxp.com/webapp/Download?colCode=AN5207

There is an example.

I_out is the expected I_SUP current in your application.

Regards,

Daniel

[NoahXu]

Hi, Daniel

thanks,  i test and find you are right about the boost switch on /off voltage.

but i have a problem is the nosie of the inductor, the lower the vsup voltage is , the louder the noise of the inductor. 

which value should i config to eliminate the nosie?

the parameter of the circuit is atatched.

[danielmartynek]

Hi @NoahXu,

Around the turn on/off point, the boot converter won't be constantly switching.

Then, it depends on many factors.

Have a look at the attached presentation, slides 23-28.

Regards,

Daniel

[NoahXu · Accepted solution]

ok, thank you .