Measuring Output Ripple Voltage Problem

ericgibbs

Joined Jan 29, 2010
16,808
hi,
E

Electronic_Maniac

Joined Oct 26, 2017
253
hi,
E
0

Boost IC = NCV3063
Vin = 8V
Vout = 23V
Iout(max) = 250mA - (Load is a constant current circuit which is enabled at 200Hz)
Schematic

Mentioned the points where I have probed

Waveforms (Same waveform, only varying the timescale) :

Why is there a dip in output current and increase in output ripple voltage at the marked areas?

And which waveform describes the right Peak to Peak ripple voltage measurement?

This :

Or

Or

Last edited:

ericgibbs

Joined Jan 29, 2010
16,808
hi EM,
I always measure the ripple voltage at the output of power supply, when it is loaded with a fixed load that draws the maximum current specified for the PSU.

What is the duty cycle of this switched load.?
Iout(max) = 250mA - (Load is a constant current circuit which is enabled at 200Hz)

E

Electronic_Maniac

Joined Oct 26, 2017
253
hi EM,
I always measure the ripple voltage at the output of power supply, when it is loaded with a fixed load that draws the maximum current specified for the PSU.

What is the duty cycle of this switched load.?
Iout(max) = 250mA - (Load is a constant current circuit which is enabled at 200Hz)

E
Hello,

I too measured the ripple voltage at the output of the power supply as I mentioned in the diagram. Please tell me which waveform is correct.

And the duty cycle is 90%

ericgibbs

Joined Jan 29, 2010
16,808
hi,
Ref this image, use a fixed load that draws 250mA while doing the test.
E

Electronic_Maniac

Joined Oct 26, 2017
253
hi,
Ref this image, use a fixed load that draws 250mA while doing the test.
E
View attachment 190105
But why should I not do like how I do? What's wrong with my own load at the board

ericgibbs

Joined Jan 29, 2010
16,808
hi,
This image shows the response time of the PSU caused by switching the 250mA Load On/Off.
E

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Electronic_Maniac

Joined Oct 26, 2017
253

ericgibbs

Joined Jan 29, 2010
16,808

Why is there a dip in output current and increase in output ripple voltage at the marked areas?
Because your switched Load is creating the change in the circuit response waveforms

And which waveform describes the right Peak to Peak ripple voltage measurement?
As per my post #6

But why should I not do like how I do? What's wrong with my own load at the board
Because your switched Load is creating the change in the circuit response waveforms

If I have missed a point, please repost a particular question.

E