EEVblog Electronics Community Forum

Electronics => Beginners => Topic started by: sk614 on June 01, 2016, 05:51:37 pm

Title: Pulsed Output to Continuous conversion.
Post by: sk614 on June 01, 2016, 05:51:37 pm
Is it possible to convert a pulsed output voltage to a continuous output voltage? Specifically, I am looking at this device P2110 RF Harvester Receiver.  http://www.powercastco.com/test566alpha/wp-content/uploads/2009/03/p2110-datasheet-rev-b.pdf (http://www.powercastco.com/test566alpha/wp-content/uploads/2009/03/p2110-datasheet-rev-b.pdf).  On page 3 Vout is Pulsed...are there ways to convert that to continuous?

Would using a PWM to analog such as this http://www.ti.com.cn/cn/lit/an/spraa88a/spraa88a.pdf  (http://www.ti.com.cn/cn/lit/an/spraa88a/spraa88a.pdf)work?

Edit:
Title: Re: Pulsed Output to Continuous conversion.
Post by: danadak on June 01, 2016, 07:01:59 pm
Thge TI ap note is an excellent way of handling this. Basically you are
building a LPF, Integrator, and that will convert to pulse to avg DC,
with some ripple as discussed in ap note.

Note this is for a periodic waveform. If waveform aperiodic burst you
will need to allow for settling time in LPF design as another consideration.
Depending on waveform this could force you into an active design.

What is the range of pulse width you are getting and desired resolution
and accuracy you want for the DC out ?

Another ap note TI did attached.


Regards, Dana.
Title: Re: Pulsed Output to Continuous conversion.
Post by: sk614 on June 02, 2016, 02:34:34 pm
Thanks! I am planning ahead to see if it is possible to do.  My plan is to convert the pulsed signal of the P2110 RF Receiver.  Question: Since I can only get the average DC of the pulse, what can I do to boost the signal up to peak voltage of the pulse?
Title: Re: Pulsed Output to Continuous conversion.
Post by: danadak on June 02, 2016, 03:49:17 pm
Then consider peak detection circuit

http://ww1.microchip.com/downloads/en/AppNotes/01353A.pdf (http://ww1.microchip.com/downloads/en/AppNotes/01353A.pdf)

http://cds.linear.com/docs/en/design-note/dn61f.pdf (http://cds.linear.com/docs/en/design-note/dn61f.pdf)

https://www.maximintegrated.com/en/app-notes/index.mvp/id/1163 (https://www.maximintegrated.com/en/app-notes/index.mvp/id/1163)

http://www.intersil.com/content/dam/Intersil/documents/an10/an1097.pdf (http://www.intersil.com/content/dam/Intersil/documents/an10/an1097.pdf)

https://www.intersil.com/content/dam/Intersil/documents/an51/an517.pdf (https://www.intersil.com/content/dam/Intersil/documents/an51/an517.pdf)

http://www.cypress.com/file/113046/download (http://www.cypress.com/file/113046/download)

http://www.cypress.com/file/134261/download (http://www.cypress.com/file/134261/download)


Regards, Dana.
Title: Re: Pulsed Output to Continuous conversion.
Post by: rfeecs on June 02, 2016, 04:55:33 pm
I don't see that the output is necessarily pulsed.  According to the description:
Quote
The P2110 converts RF energy to
DC and stores it in a capacitor. When a
charge threshold on the capacitor is
achieved, the P2110 boosts the voltage to
the set output voltage level and enables the
voltage output. When the charge on the
capacitor declines to the low voltage
threshold the voltage output is turned off.

It sounds like as long as you have enough voltage available in the storage capacitor, the output will be turned on.  The device already does energy storage and boosts the voltage.  I don't see that you need anything else.  In fact, adding additional circuitry would just waste energy.