LP8758-E0: Vout Start-up

Hi Yuto,

Do you have any active loads on the device during start-up? During soft-start the slew rate of the device is about 5mV/us. This slew rate is maintained until the output voltage reaches 300mV. Then the output continues to ramp-up at the .47mV/us slew-rate. How much input capacitance do you have? Also, how much output capacitance is on the rail?

-Raymundo Hernandez-Toscano

Hi Raymundo-san,

Thank you for your reply.
I measured with EVM of LP8758-E0 without load.

Regards,
Yuto Sakai

Hi Yuto,

Could you provide a bit more information regarding your test setup? Is the device in single or multi phase operation? Also, where and how was the measurement taken? I want to ensure that there isn't any stray inductance that could potentially be causing this. Could you add a .1uF capacitor to the output and repeat your measurement?

-Raymundo Hernandez-Toscano

Hi Raymundo-san,

【Condition】
・The device is in single operation.
・Use LP8758-E0 EVM with nothing changed
・VIN=3.3V,VOUT=0.98V,Startup delay:10ms,slew rate:0.47mV/μs

Also,It is possible to repeat my measurement with additional 0.1uF capacitor to the output.

Best Regards,
Yuto Sakai