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  331   Tue Feb 18 14:12:37 2014 Stefan RittAnnouncement of new Evaluation Board V5

Stefan Ritt wrote:

Dear DRS community,

starting from this year, we ship the new evaluation board V5. This board has an improved internal timing calibration, with which one can measure the time with a precision down to a few ps. Following picture shows the time between two pulses, obtained with a function generator, a passive split and a delay cable. The single threshold time estimator of the DRSOsc program obtains with such signal a resolution of 2.5 ps (RMS).

Using more sophisticated algorithms such as cross-correlation, resolutions below 1 ps were already achieved.

The new board can now be ordered at the same price than the V4 board, delivery will start in March 2014.

Best regards,
Stefan Ritt
 

The new software for the V5 evaluation board has been released today with following new features:

  • Hardware scalers for all four channels and the trigger working up to 200 MHz. With the trigger scaler one can measure for example coincidence rates between two channels.
  • New vertical and horizontal "slice" measurements. This allows to measure the amplitude of a signal at a certain time relative to the trigger point or the time when a signal crosses a certain level.
  • Gated charge measurement allowing to measure the charge of a signal between two time markers, like an old-fashioned charge integrating ADC.

The software is available at the the usual location http://www.psi.ch/drs/software-download for Linux, Windows and Mac OSX. I'm working right now to get it also into the Apple App Store.

/Stefan

Attachment 1: scope.png
scope.png
  351   Mon Jun 9 12:03:26 2014 Osip LishilinAnnouncement of new Evaluation Board V5

Stefan Ritt wrote:

Hardware scalers for all four channels and the trigger working up to 200 MHz. With the trigger scaler one can measure for example coincidence rates between two channels.

 Does it give the ability to measure triggering rate? I'm talking again about possibility of use DRS4 as pulse counter for PMT's. If yes, do I need new v5 board or it is possible to use v4 board?

  352   Wed Jun 11 11:13:50 2014 Stefan RittAnnouncement of new Evaluation Board V5

Osip Lishilin wrote:

Stefan Ritt wrote:

Hardware scalers for all four channels and the trigger working up to 200 MHz. With the trigger scaler one can measure for example coincidence rates between two channels.

 Does it give the ability to measure triggering rate? I'm talking again about possibility of use DRS4 as pulse counter for PMT's. If yes, do I need new v5 board or it is possible to use v4 board?

Yes it is possible to measure the raw trigger rate, with a resolution of 10 Hz. You need a new V5 board for that. 

  356   Mon Jun 16 15:35:59 2014 Osip LishilinAnnouncement of new Evaluation Board V5

Stefan Ritt wrote:

Osip Lishilin wrote:

Stefan Ritt wrote:

Hardware scalers for all four channels and the trigger working up to 200 MHz. With the trigger scaler one can measure for example coincidence rates between two channels.

 Does it give the ability to measure triggering rate? I'm talking again about possibility of use DRS4 as pulse counter for PMT's. If yes, do I need new v5 board or it is possible to use v4 board?

Yes it is possible to measure the raw trigger rate, with a resolution of 10 Hz. You need a new V5 board for that. 

I'm not sure if I understand you correctly. The trigger rate could be up to 200 MHz, and it's possible to measure it  with 10 Hz resolution. Is it right?

Does it possible to measure independent trigger rate for each channel?

  99   Mon Jul 12 16:07:37 2010 Stefan RittAnnouncement evaluation board V3

Dear DRS4 users,

a new version of the evaluation board has been designed and is in production now. The main difference is that it uses active input amplifiers, which result in an analog bandwidth of 700 MHz (as compared with the 220 MHz of the previous board) at moderate power consumption, so the board can still be powered by the USB port. New orders will receive boards V3, the old V2 boards are not available any more.

It is mandatory to use the software revision 3.0.0 or later with the new board. This software has also many new features in the oscilloscope application, and together with the new firmware it reduces the noise of the board below 0.5 mV RMS. Although the software can be used with old V2 boards, some limitations might apply due to the old firmware of the boards. People having a Xilinx download cable can flash the firmware contained in the 3.0.0 revision to their V2 board to get all features of the new software.

The evaluation board manual V3 contains the new schematics of the analog inputs using the THS4508 differential amplifier, so people doing their own design can use this schematics as and example.

Best regards,

   Stefan Ritt

Attachment 1: eval3.png
eval3.png
  116   Fri Feb 25 10:13:51 2011 Stefan RittAnnouncement digital pulse processing workshop

Dear colleague,

if you live not so far from Zurich, you might be interested in this workshop:

http://www.xtronix.ch/hep/psi_workshop.htm

This is a combined PSI-CAEN presentation of digitizer hardware including the new V1742 board based on the DRS4 chip. The workshop will also show how digital pulse processing can be used to effectively extract time and energy from detector signals, and thus replace more and more traditional analog electronics. Please register at the above site if you are interested.

Best regards,

    Stefan Ritt

  6   Mon Apr 27 15:09:49 2009 Stefan RittAmplitude and Timing calibration for DRS4 Evaluation Board

This is a quick notification to all users of the current DRS4 evaluation board.

As you all know, the DRS4 chip needs some calibration for each individual cell which corrects the offset and the non-equidistant width in time. While the first evaluation boards have been shipped without this calibration, the current version of the software implements a full amplitude and timing calibration. The offset correction reduces the noise of the board by almost an order of magnitude to below 1 mV RMS. The timing calibration using an on-board reference clock allows a timing accuracy in the order of 10 ps. To illustrate that the following two pictures show a reference clock signal before and after timing calibration:

uncal.png

cal.png

The integral temporal nonlineairy at 5 GSPS before timing calibration is about 600 ps as can be seen by the jitter of the overlaid waveforms.

In order to do a timing calibration, the firmware revison 13297 or later is required. The current software package 2.1 contains an updated firmware, but unfortunately one needs a Xilinx download cable to flash this new firmware (see http://drs.web.psi.ch/download/ under "Software Versions"). If some people want an update but do not want to buy such a cable, we offer a free update at our institute (just the postage has to be paid). The old evaluation board (Rev. 1.0, plastic housing) can unfortunately not be updated.

After the offset calibration is made, there are small (~20mV) short spikes left. They probably come from some cross-talk between the USB interface and the analog part of the board. This is currently under investigation. If new updates become available, they will be announced in this forum.

 

April 27th, 2009,

Stefan Ritt

  584   Sat Jan 28 14:11:58 2017 Danny PetschkeAND trigger problems

 Dear Stefan,

I have 2 identical pulses as a splittet signal with an amplitude of 300mV. Range is -0.5-0.5V, 5.12GSamp using the Evaluation-Board. Both signals are triggered in AND logic. One of the signals is delayed by a fixed value of 1-50ns for testing. On increasing the trigger Level from 10% to 50% of amplitude (pulse rise time is 2.5ns) pulses cannot anymore triggered above 4-5ns delay. It means there is a proportionality between the trigger level and the available range where 2 signals can be triggered in AND logic (Time-difference between 2 pulses). Do I anything misunderstand or is the time the comparator needs by higher trigger Levels for comparation longer than the 200ns at 5.12GSamp?

Board was timing and voltage calibrated before.

Thx

Danny

  585   Mon Jan 30 16:37:33 2017 Stefan RittAND trigger problems

In the evaluation board we use an ADCMP601 comparator, which has a setup and hold time of 4.6 ns. So a pulse which exceeds the threshold for less than 4.6 ns will not trigger the board. If you AND two signals together, an additional constraint might apply on the coincidence pulse. This is processed in the FPGA, but once it becomes too short, it won't trigger the board as well. I never made a real measurement of that, but I would not be suprised if the coicidence signal (output of AND), needs to be at least 4-5 ns wide.

If you need more refined trigger conditions, make yourself an old-fashioned external trigger (with NIM modules for example), stretch the output to 10 ns and feed it into the external trigger input of the DRS4 board (5V CMOS logic, not NIM!).

Best,

Stefan

Danny Petschke wrote:

 Dear Stefan,

I have 2 identical pulses as a splittet signal with an amplitude of 300mV. Range is -0.5-0.5V, 5.12GSamp using the Evaluation-Board. Both signals are triggered in AND logic. One of the signals is delayed by a fixed value of 1-50ns for testing. On increasing the trigger Level from 10% to 50% of amplitude (pulse rise time is 2.5ns) pulses cannot anymore triggered above 4-5ns delay. It means there is a proportionality between the trigger level and the available range where 2 signals can be triggered in AND logic (Time-difference between 2 pulses). Do I anything misunderstand or is the time the comparator needs by higher trigger Levels for comparation longer than the 200ns at 5.12GSamp?

Board was timing and voltage calibrated before.

Thx

Danny

 

  616   Thu Jun 8 14:26:23 2017 Rebecca SchmitzAND Trigger problems with 2-3 channels

Hello,

I work with the DRS4 Evaluation Board V5 and I have a problem with the software.

I have a problem with the AND trigger setting.
For this I have chosen the AND trigger function. However, when ONE channel senses an impulse, it triggers. I'm not able to see signals in the other channels, which I selected for the coincidence.

What is the cause of this? Maybe the time window?

I would like to measure a coincidence with two or three random channels. Is it possible?

Thanks for the help.

Rebecca

  617   Thu Jun 8 15:52:20 2017 Stefan RittAND Trigger problems with 2-3 channels

Can you post a screenshot where I can see the channel waveforms, the configuration and the trigger settings?

Stefan

Rebecca Schmitz wrote:

Hello,

I work with the DRS4 Evaluation Board V5 and I have a problem with the software.

I have a problem with the AND trigger setting.
For this I have chosen the AND trigger function. However, when ONE channel senses an impulse, it triggers. I'm not able to see signals in the other channels, which I selected for the coincidence.

What is the cause of this? Maybe the time window?

I would like to measure a coincidence with two or three random channels. Is it possible?

Thanks for the help.

Rebecca

 

  618   Fri Jun 9 09:44:33 2017 Rebecca SchmitzAND Trigger problems with 2-3 channels

Hello,

It seems that a coincidence with two fixed channels suddenly works. I don't know why.

Screenshot 1 shows the trigger settings for the coincidence with two channels.
Screenshot 2 shows the oscilloscope surface.
Screenshot 3 shows the configuration. In the background there is a coincidence with three channels.

In contrast to the coincidence with two channels this doesn't look good.

Rebecca

Stefan Ritt wrote:

Can you post a screenshot where I can see the channel waveforms, the configuration and the trigger settings?

Stefan

Rebecca Schmitz wrote:

Hello,

I work with the DRS4 Evaluation Board V5 and I have a problem with the software.

I have a problem with the AND trigger setting.
For this I have chosen the AND trigger function. However, when ONE channel senses an impulse, it triggers. I'm not able to see signals in the other channels, which I selected for the coincidence.

What is the cause of this? Maybe the time window?

I would like to measure a coincidence with two or three random channels. Is it possible?

Thanks for the help.

Rebecca

 

 

Attachment 1: Screenshot1.png
Screenshot1.png
Attachment 2: Screenshot2.png
Screenshot2.png
Attachment 3: Screenshot3.png
Screenshot3.png
  620   Thu Jun 22 21:36:08 2017 Stefan RittAND Trigger problems with 2-3 channels

Hi,

from our screenshots I see the following:

- you have sometimes a huge oscillation in your preamplifier. Fix this first before doing any waveform recording

- your signals are barely 20 mV, and your trigger threshold is 20 mV. The coincidence only triggers when both signals are below the trigger threshold at the same time, and the overlap must be longer than 4-5 ns. So if your signals  are not exactly in time, you won't get a coincidence trigger

Stefan

 

Rebecca Schmitz wrote:

Hello,

It seems that a coincidence with two fixed channels suddenly works. I don't know why.

Screenshot 1 shows the trigger settings for the coincidence with two channels.
Screenshot 2 shows the oscilloscope surface.
Screenshot 3 shows the configuration. In the background there is a coincidence with three channels.

In contrast to the coincidence with two channels this doesn't look good.

Rebecca

Stefan Ritt wrote:

Can you post a screenshot where I can see the channel waveforms, the configuration and the trigger settings?

Stefan

Rebecca Schmitz wrote:

Hello,

I work with the DRS4 Evaluation Board V5 and I have a problem with the software.

I have a problem with the AND trigger setting.
For this I have chosen the AND trigger function. However, when ONE channel senses an impulse, it triggers. I'm not able to see signals in the other channels, which I selected for the coincidence.

What is the cause of this? Maybe the time window?

I would like to measure a coincidence with two or three random channels. Is it possible?

Thanks for the help.

Rebecca

 

 

 

  364   Thu Aug 21 11:03:36 2014 Martin Petriska10GSps on DRS4 Evm with delay cables

 Hi, I read its possible to use channels 2,4,6 to extend 200ns to 400ns (1024bins to 2048).

Is it possible to use same channels to double sampling rate with paralel feeding, one channel delayed by Ts/2, for 5,12GS/s is it cca 3cm delay cable?

 

Martin

  365   Tue Aug 26 12:32:21 2014 Stefan Ritt10GSps on DRS4 Evm with delay cables

Martin Petriska wrote:

 Hi, I read its possible to use channels 2,4,6 to extend 200ns to 400ns (1024bins to 2048).

Is it possible to use same channels to double sampling rate with paralel feeding, one channel delayed by Ts/2, for 5,12GS/s is it cca 3cm delay cable?

 

Martin

In principle yes (you could split your signal externally and add some cable delay to one side), but it is not supported by the software. You would have to combine the data from the two channels yourself. But it won't help much. The analog bandwidth of the evaluation board is about 700 MHz. So sampling at 10 GSPS vs. 5 GSPS won't give you any additional information, since the highest frequencies in your signal will be only 700 MHz. You could as well take your 5 GSPS measurement and interpolate it with some sinc function to get exactly the same result. See here for details: http://en.wikipedia.org/wiki/Whittaker%E2%80%93Shannon_interpolation_formula 

  697   Thu May 17 13:29:34 2018 Stefan Ritt"Symmetric spikes" fixed

Good news for all DRS4 users. After many years, I finally understand where the "symmetric spikes" come from and how to fix them.

The "symmetric spikes" are small spikes of 17-18mV, which randomly happen at 1-2 cells. They alwas come in groups of 2 in each channel, symmetric around sampling cell #512. See first attachment.

The reason for the spikes is the previous readout cycle. On each readout cycle, the "read bit" is clocked through all 1024 cells to switch one cell contents to the DRS4 output. At the end of the 1024 cycles, the read bit stays at its last position. The bit is carried by a metal line on the chip, which crosses all 9 channels (second attachment). This bit now influences the sampling cells below the metal line capacitively, so their contents is "pushed up" by a few mV, just like the ROFS offset does. Since the DRS sampling channels are in a snake layout, going 0-512 from left, then 512-1023 back again, the line crosses two cells in each channel, and thus the symmetric spikes.

Previously, there was a software solution for that. In the evaluation board software DRSOsc there is a button "Remove spikes" which tries to fix this in software. Although this works most of the time, it's annoying and not 100% safe. Like when the spike sits on top of a noise signal, it might not be recognized. Fixing this in hardware is however straight forwar. After the readout cycle ends, push the read bit out of the chip:

  • Address the read shift register by applying 1011b to A3:A0
  • Switch SRIN low
  • Apply 1024 clock cycles to SRCLK

This shifts the bit out of the chip, so that the next event is not affected by the read bit. The third attachment show the effect of this. The "clear cycle" increases the readout time a little bit, but depending on the application this might be worth it.

Regards,
Stefan

Attachment 1: with.png
with.png
Attachment 2: Screen_Shot_2018-05-17_at_13.30.23_.png
Screen_Shot_2018-05-17_at_13.30.23_.png
Attachment 3: without.png
without.png
  714   Mon Sep 3 11:17:26 2018 Martin Petriska"Symmetric spikes" fixed

Hi,

Is it possible to fix it by FPGA changes?  I see readout cycle (proc_drs_reedout) in drs4_eval(4)5_app.vhd, but not sure where to exactly put this three commands. Could you please attach app.vhd file for eval board with example how to fix ?

Regards,

Martin

 

Stefan Ritt wrote:

Good news for all DRS4 users. After many years, I finally understand where the "symmetric spikes" come from and how to fix them.

The "symmetric spikes" are small spikes of 17-18mV, which randomly happen at 1-2 cells. They alwas come in groups of 2 in each channel, symmetric around sampling cell #512. See first attachment.

The reason for the spikes is the previous readout cycle. On each readout cycle, the "read bit" is clocked through all 1024 cells to switch one cell contents to the DRS4 output. At the end of the 1024 cycles, the read bit stays at its last position. The bit is carried by a metal line on the chip, which crosses all 9 channels (second attachment). This bit now influences the sampling cells below the metal line capacitively, so their contents is "pushed up" by a few mV, just like the ROFS offset does. Since the DRS sampling channels are in a snake layout, going 0-512 from left, then 512-1023 back again, the line crosses two cells in each channel, and thus the symmetric spikes.

Previously, there was a software solution for that. In the evaluation board software DRSOsc there is a button "Remove spikes" which tries to fix this in software. Although this works most of the time, it's annoying and not 100% safe. Like when the spike sits on top of a noise signal, it might not be recognized. Fixing this in hardware is however straight forwar. After the readout cycle ends, push the read bit out of the chip:

  • Address the read shift register by applying 1011b to A3:A0
  • Switch SRIN low
  • Apply 1024 clock cycles to SRCLK

This shifts the bit out of the chip, so that the next event is not affected by the read bit. The third attachment show the effect of this. The "clear cycle" increases the readout time a little bit, but depending on the application this might be worth it.

Regards,
Stefan

 

  715   Tue Sep 4 13:04:30 2018 Stefan Ritt"Symmetric spikes" fixed

Yes it's possible, but I have to find time for that. The software of the evaluation board takes care of the spikes ("remove spikes"), so I thought it's not so urgent to fix that in the FPGA (which takes me some time).

Stefan

Martin Petriska wrote:

Hi,

Is it possible to fix it by FPGA changes?  I see readout cycle (proc_drs_reedout) in drs4_eval(4)5_app.vhd, but not sure where to exactly put this three commands. Could you please attach app.vhd file for eval board with example how to fix ?

Regards,

Martin

 

Stefan Ritt wrote:

Good news for all DRS4 users. After many years, I finally understand where the "symmetric spikes" come from and how to fix them.

The "symmetric spikes" are small spikes of 17-18mV, which randomly happen at 1-2 cells. They alwas come in groups of 2 in each channel, symmetric around sampling cell #512. See first attachment.

The reason for the spikes is the previous readout cycle. On each readout cycle, the "read bit" is clocked through all 1024 cells to switch one cell contents to the DRS4 output. At the end of the 1024 cycles, the read bit stays at its last position. The bit is carried by a metal line on the chip, which crosses all 9 channels (second attachment). This bit now influences the sampling cells below the metal line capacitively, so their contents is "pushed up" by a few mV, just like the ROFS offset does. Since the DRS sampling channels are in a snake layout, going 0-512 from left, then 512-1023 back again, the line crosses two cells in each channel, and thus the symmetric spikes.

Previously, there was a software solution for that. In the evaluation board software DRSOsc there is a button "Remove spikes" which tries to fix this in software. Although this works most of the time, it's annoying and not 100% safe. Like when the spike sits on top of a noise signal, it might not be recognized. Fixing this in hardware is however straight forwar. After the readout cycle ends, push the read bit out of the chip:

  • Address the read shift register by applying 1011b to A3:A0
  • Switch SRIN low
  • Apply 1024 clock cycles to SRCLK

This shifts the bit out of the chip, so that the next event is not affected by the read bit. The third attachment show the effect of this. The "clear cycle" increases the readout time a little bit, but depending on the application this might be worth it.

Regards,
Stefan

 

 

  716   Thu Sep 13 18:09:13 2018 Martin Petriska"Symmetric spikes" fixed

Ok, so I made it ... and Yes it works :), 

https://youtu.be/0noy4CoFoh8 

here is changed part in drs4_eval4_app.vhd

               
        when done =>
          drs_readout_state    <= spikeoff;
          drs_stat_busy        <= '0';
          drs_dpram_we1        <= '0';
          drs_write_set        <= '1';   -- set drs_write_ff in proc_drs_write
                                         -- to keep chip "warm"

 -- spike fix ELOG 697        
 
          when spikeoff => 
            o_drs_addr       <= "1011"; -- Address the read shift register by applying 1011b to A3:A0
            o_drs_srin       <= '0'; -- Switch SRIN low             
             drs_readout_state                 <= spikecycle;
             -- Apply 1024 clock cycles to SRCLK     
             drs_sr_count         <= 0;

          when spikecycle =>      
             drs_sr_count         <= drs_sr_count + 1;
             o_drs_srclk          <= not o_drs_srclk;
             if (drs_sr_count = 1024) then
                drs_readout_state <= idle;
             end if;      


        -- set-up of configuration register        

Stefan Ritt wrote:

Yes it's possible, but I have to find time for that. The software of the evaluation board takes care of the spikes ("remove spikes"), so I thought it's not so urgent to fix that in the FPGA (which takes me some time).

Stefan

Martin Petriska wrote:

Hi,

Is it possible to fix it by FPGA changes?  I see readout cycle (proc_drs_reedout) in drs4_eval(4)5_app.vhd, but not sure where to exactly put this three commands. Could you please attach app.vhd file for eval board with example how to fix ?

Regards,

Martin

 

Stefan Ritt wrote:

Good news for all DRS4 users. After many years, I finally understand where the "symmetric spikes" come from and how to fix them.

The "symmetric spikes" are small spikes of 17-18mV, which randomly happen at 1-2 cells. They alwas come in groups of 2 in each channel, symmetric around sampling cell #512. See first attachment.

The reason for the spikes is the previous readout cycle. On each readout cycle, the "read bit" is clocked through all 1024 cells to switch one cell contents to the DRS4 output. At the end of the 1024 cycles, the read bit stays at its last position. The bit is carried by a metal line on the chip, which crosses all 9 channels (second attachment). This bit now influences the sampling cells below the metal line capacitively, so their contents is "pushed up" by a few mV, just like the ROFS offset does. Since the DRS sampling channels are in a snake layout, going 0-512 from left, then 512-1023 back again, the line crosses two cells in each channel, and thus the symmetric spikes.

Previously, there was a software solution for that. In the evaluation board software DRSOsc there is a button "Remove spikes" which tries to fix this in software. Although this works most of the time, it's annoying and not 100% safe. Like when the spike sits on top of a noise signal, it might not be recognized. Fixing this in hardware is however straight forwar. After the readout cycle ends, push the read bit out of the chip:

  • Address the read shift register by applying 1011b to A3:A0
  • Switch SRIN low
  • Apply 1024 clock cycles to SRCLK

This shifts the bit out of the chip, so that the next event is not affected by the read bit. The third attachment show the effect of this. The "clear cycle" increases the readout time a little bit, but depending on the application this might be worth it.

Regards,
Stefan

 

 

 

  106   Wed Jul 21 10:46:32 2010 Jinhong Wang ENOB of DRS

 Hi, Stefan, I see in your ppt "Design and performance of 6 GSPS waveform digitizing chip DRS4" , you define DRS4 ENOB as 1Vpp/0.35mv(RMS) = 11.5bit, where, 1Vpp is the linearity input range, and 0.35mv is the rms voltage after offset correction. What I understand is that 0.35mV is obtained from DC offset Correction, hence 11.5 bit is for DC input, am i right?  If true, what about ENOB for AC input in the whole analog bandwidth?  thanks~

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