| Kai Klaas 03/16/06 09:02 Read: 960 times Germany |
#112314 - Some hints Responding to: Prahlad J. Purohit's previous message |
Prahlad said:
I added the 6 hole ferrite that i use with my micro supplies RS order code 260-6818 Type 7427501 Wurth make. It has 800E impedence at 100MHz & 598E at 25MHz. The bead can be seen in the CD4060 gnd plane and the 100E resistor crossing the bridge. Is it ok? Perfectly! Prahlad said:
I conencted second cap to CD4060 supply line in analog section to form a PI filter is the connection ok? What value this cap should be for optimum results? Connection is alright. For optimum results caps of a pi-filter should be identical. So, you need to add a 100nF. Prahlad said:
I also connected a resistor in the oscillator output [signal] line where it crosses the bridge. What value this resistor should be? A cap is also added to signal line after the resistor in analog plane to form the pi filter what value this cap should be? Make an 1k resistor cross the gap and use two 47n caps at both sides of the gap. Prahlad said:
Reinforced the top and bottom layers gnd with lots of vias. Well done. But some of them are a bit too close to other solder pads. For instance at C11. A few more points: - C11 is an electrolytic cap. Your schematic shows a biplor cap though. - I have made a serious drawing mistake: At the active filter stages all the first caps must be connected to output of according OPamps of course, not to ground! Wondered, that nobody has noticed this in the meantime... I appologize! - Due to the power supply filters in each supply line of OPamp, there's no need to route the +15V and -15V lines from a star point to each OPamp! You can save a lot of PCB area by this and use it for the ground planes. Your board looks very nice now, like a professional one! Good luck, Kai |
| Topic | Author | Date |
| Measuring capacitance very precisely. | Prahlad J. Purohit | 02/13/06 09:06 |
| "I want the best money can buy, but I do | Erik Malund | 02/13/06 09:24 |
| In this specific case I disagree. | Kalpak Dabir | 02/13/06 11:22 |
| Bridge? | Andy Neil | 02/13/06 09:31 |
| Bridge! | Oliver Sedlacek | 02/13/06 09:58 |
| AC bridge | Steve M. Taylor | 02/13/06 14:19 |
| Error Sources | Bruce Bailey | 02/13/06 15:04 |
Blumlein Bridge  | Steve M. Taylor | 02/13/06 16:59 |
| Blumlein Bridre. | Prahlad J. Purohit | 02/14/06 22:11 |
| Bridge excitation | Oliver Sedlacek | 02/15/06 03:18 |
| Blumlein | Ian Bell | 02/16/06 03:21 |
| Let the statistics be your friend... | Kai Klaas | 02/13/06 19:19 |
| frequency meter | Christian Kleiber | 02/14/06 07:30 |
| Product as a Transfer Standard | Bruce Bailey | 02/14/06 09:31 |
| Distributor of your confidence | Kai Klaas | 02/22/06 07:17 |
| Suppliers like that ... | Bruce Bailey | 02/22/06 07:58 |
| why blame the suppliers | Erik Malund | 02/22/06 08:06 |
| Not at all | Kai Klaas | 02/22/06 10:08 |
| Hah! | Bruce Bailey | 02/22/06 10:28 |
| Statistics for reference determination. | Prahlad J. Purohit | 02/15/06 00:02 |
| You got it! | Kai Klaas | 02/15/06 07:42 |
| questions | Erik Malund | 02/15/06 06:24 |
| he wants to select to 0.1% from 1% stock | Terry Lingle | 02/15/06 07:13 |
| that is a bad idea | Erik Malund | 02/15/06 07:54 |
| Hmm | Kai Klaas | 02/15/06 08:10 |
| That's a good way | Kai Klaas | 02/15/06 07:48 |
| posts cross timed | Erik Malund | 02/15/06 08:04 |
| It makes sense to select them | Kai Klaas | 02/15/06 08:18 |
| No sorting of Caps. | Prahlad J. Purohit | 02/15/06 08:16 |
| then, are you not using the wrong approa | Erik Malund | 02/15/06 09:27 |
| Time constant | Kai Klaas | 02/15/06 10:16 |
| Re: Eliminate cap sorting | Prahlad J. Purohit | 02/15/06 22:06 |
| Example | Steve M. Taylor | 02/16/06 02:57 |
| you do not need precision, you need rate | Erik Malund | 02/16/06 06:36 |
| Would it not be easier the other way? | Kalpak Dabir | 02/15/06 10:35 |
| Difficult | Kai Klaas | 02/15/06 11:45 |
| Yes Digital Difficult. | Prahlad J. Purohit | 02/15/06 21:58 |
| I think the point has been missed again. | Jez Smith | 02/16/06 07:54 |
| Demo ? | Steve M. Taylor | 02/16/06 09:28 |
| Difficult to change now. | Prahlad J. Purohit | 02/16/06 09:48 |
| Don't worry | Kai Klaas | 02/16/06 09:59 |
| Re: Dont Worry. | Prahlad J. Purohit | 02/17/06 08:07 |
| How to calibrate an integrator? | Kai Klaas | 02/19/06 13:29 |
| Re: How to calib. an integratrator. | Prahlad J. Purohit | 02/19/06 21:59 |
| Answers | Kai Klaas | 02/20/06 06:33 |
| 256Hz too fast. | Prahlad J. Purohit | 02/20/06 02:51 |
| Integrator and RMS using DSP | Kalpak Dabir | 02/20/06 03:17 |
| Whats available easily. | Prahlad J. Purohit | 02/20/06 09:38 |
| dsPIC30F2010 | Kalpak Dabir | 02/20/06 09:49 |
| 500 kSPS | Mahmood Elnasser | 03/16/06 09:43 |
| This little PICcy got eaten, the SILabs | Erik Malund | 03/16/06 10:33 |
| Is that useful? | Kalpak Dabir | 03/19/06 07:09 |
| Planning to use dspic. | Prahlad J. Purohit | 03/19/06 07:35 |
| Speed ? | Steve M. Taylor | 03/19/06 07:55 |
| But for what purpose? | Kalpak Dabir | 03/19/06 11:36 |
| MAC | Steve M. Taylor | 03/19/06 12:16 |
| it is amazing | Erik Malund | 03/20/06 07:41 |
| Here is the analysis | Kalpak Dabir | 03/20/06 09:36 |
| the content, not the words | Erik Malund | 03/20/06 10:54 |
| analysis please | Kalpak Dabir | 03/20/06 11:38 |
| since you, just like me, have no idea ab | Erik Malund | 03/20/06 13:12 |
| Ah! The Horatio quote version 2! | Kalpak Dabir | 03/20/06 19:30 |
| again, you focus on words, not content | Erik Malund | 03/21/06 06:45 |
| Which is why I asked... | Kalpak Dabir | 03/21/06 11:34 |
| If what you are saying is that I can not | Erik Malund | 03/21/06 12:29 |
| I had to. | Steve M. Taylor | 03/21/06 13:52 |
| You said it! | Kalpak Dabir | 03/22/06 00:07 |
| Analog integrator | Kai Klaas | 03/20/06 18:48 |
| How do you calculate the RMS? | Kai Klaas | 02/20/06 06:48 |
| RMS in detail. | Prahlad J. Purohit | 02/20/06 09:35 |
| Out of interest. | Steve M. Taylor | 02/20/06 11:53 |
| wot you want a RMS demo,steve?? | Jez Smith | 02/21/06 04:52 |
| FIXED point | Steve M. Taylor | 02/21/06 11:13 |
| fixed point is almost as bad | Jez Smith | 02/21/06 14:16 |
| Alternative | Kai Klaas | 02/20/06 13:30 |
| NCO again | Steve M. Taylor | 02/20/06 16:17 |
| Would be nice | Kai Klaas | 02/22/06 06:45 |
| Timer2 of 89C52 | Kalpak Dabir | 02/22/06 06:58 |
| clever | Steve M. Taylor | 02/22/06 08:38 |
| Oops! Incomplete statement | Kalpak Dabir | 02/22/06 10:11 |
| Clock feedthrough | Kai Klaas | 02/22/06 10:38 |
| Maxim App note | Steve M. Taylor | 02/22/06 10:51 |
| Nice links, thanks! | Kai Klaas | 02/22/06 10:54 |
| AD9832 | Steve M. Taylor | 02/22/06 14:13 |
| sine vawe | Erik Malund | 02/24/06 11:35 |
| Re: Alternative. | Prahlad J. Purohit | 02/20/06 22:34 |
| Will work | Kai Klaas | 02/21/06 05:49 |
| Re: 64Hz Gain 1.126. | Prahlad J. Purohit | 02/21/06 03:41 |
| Maximum input voltage range | Kai Klaas | 02/21/06 06:17 |
| Re: Max. Input voltage Range. | Prahlad J. Purohit | 02/22/06 04:58 |
| You have got it | Kai Klaas | 02/22/06 06:44 |
| indeed, and | Erik Malund | 02/22/06 07:44 |
| Is the resistor in gnd really needed. | Prahlad J. Purohit | 02/22/06 08:11 |
| Negligible with CMOS Opamps | Kai Klaas | 02/22/06 09:16 |
| Re: Negligible with CMOS Opamps. | Prahlad J. Purohit | 02/24/06 03:08 |
| Most opamp datasheet do specify | Kalpak Dabir | 02/24/06 07:53 |
| Input Bias Current | Steve M. Taylor | 02/24/06 09:55 |
| Impedance matching | Kai Klaas | 02/24/06 20:00 |
| Re: Impedence Matching. | Prahlad J. Purohit | 02/24/06 21:33 |
| yess balancing is required and to that.. | Abhishek Singh | 02/22/06 19:09 |
| 4u7 Cap polarity and type. | Prahlad J. Purohit | 02/23/06 03:57 |
| Foil caps are needed | Kai Klaas | 02/23/06 06:04 |
| Available Capacitors. | Prahlad J. Purohit | 03/07/06 01:31 |
| This one | Kai Klaas | 03/07/06 07:39 |
| What are these MK equivalents | Prahlad J. Purohit | 03/07/06 07:51 |
| MKT, MKP, MKC, KT, KP, KC,... | Kai Klaas | 03/07/06 20:14 |
| Thanks Kai, | Prahlad J. Purohit | 03/08/06 06:17 |
| Ground Planes. | Prahlad J. Purohit | 03/09/06 08:11 |
| Have you had problems? | Kai Klaas | 03/09/06 08:16 |
| RE: Have you had problems. | Prahlad J. Purohit | 03/09/06 08:19 |
| Keep the oscillator away from output | Kai Klaas | 03/09/06 08:52 |
| Board Layouts. | Prahlad J. Purohit | 03/09/06 09:53 |
| Recommendations | Kai Klaas | 03/09/06 17:55 |
| Corrected Board | Prahlad J. Purohit | 03/10/06 01:59 |
| I try to draw it for you | Kai Klaas | 03/10/06 06:40 |
| RE: I try to draw it. | Prahlad J. Purohit | 03/11/06 08:28 |
| Here it is | Kai Klaas | 03/11/06 08:49 |
| RE: Corrected Ver 2.0 | Prahlad J. Purohit | 03/12/06 01:44 |
| Answers | Kai Klaas | 03/13/06 06:51 |
| Re: Corrected Ver. 3.0 | Prahlad J. Purohit | 03/14/06 03:30 |
| Some hints | Kai Klaas | 03/16/06 09:02 |
| Re: I am in trouble. | Prahlad J. Purohit | 03/16/06 09:35 |
| Sorry! | Kai Klaas | 03/16/06 09:44 |
| Is this schematic correct. | Prahlad J. Purohit | 03/16/06 09:45 |
| Corrections | Kai Klaas | 03/16/06 10:04 |
| Re: Correction. | Prahlad J. Purohit | 03/16/06 10:17 |
| Mylars will do | Kai Klaas | 03/16/06 18:49 |
| Corrected Board and schematics Ver 4.0 | Prahlad J. Purohit | 03/19/06 01:44 |
| Why not doing it like this? | Kai Klaas | 03/19/06 19:47 |
| Re: Corrected boards ver 5.0 | Prahlad J. Purohit | 03/20/06 03:43 |
| Some hints | Kai Klaas | 03/20/06 11:50 |
| Corrected board ver: 6.0 | Prahlad J. Purohit | 03/21/06 07:29 |
| Please remove it... | Kai Klaas | 03/21/06 07:49 |
| Yes removed Gnd plane from mount hole. | Prahlad J. Purohit | 03/21/06 08:00 |
| Looks good now | Kai Klaas | 03/21/06 08:15 |
| Does than mean Green signal. | Prahlad J. Purohit | 03/21/06 08:16 |
| Yes | Kai Klaas | 03/21/06 08:41 |
| Thanks Kai. | Prahlad J. Purohit | 03/21/06 19:44 |
| trying to understand that | Abhishek Singh | 03/13/06 21:52 |
| DC impedance of ground plane | Kai Klaas | 03/16/06 09:35 |
| bipolar swings how and where? | Abhishek Singh | 03/09/06 09:27 |
| Here | Kai Klaas | 03/09/06 09:30 |
| explain a bit please | Abhishek Singh | 03/09/06 10:19 |
| Explaination | Kai Klaas | 03/09/06 10:55 |
| Me ? | Steve M. Taylor | 02/16/06 10:20 |
| Exactly!! | Kai Klaas | 02/16/06 09:57 |
| as requested a demo.....,sort of | Jez Smith | 02/16/06 13:47 |
| simulation results of the demo...sort of | Jez Smith | 02/16/06 23:53 |
| Thanks Jez. | Prahlad J. Purohit | 02/17/06 08:01 |
| Changing Q7 to Q9. | Prahlad J. Purohit | 03/16/06 10:23 |
| AD7142/AD7745 | Aubrey Kagan | 04/10/06 07:26 |
| Only good for a few pF | Kai Klaas | 04/10/06 09:11 |
| My apologies | Aubrey Kagan | 04/10/06 09:26 |
| No need to apologize! | Kai Klaas | 04/10/06 10:43 |
| Nice part | Steve M. Taylor | 04/10/06 13:23 |
| Built Precision Sine Wave Generator. | Prahlad J. Purohit | 04/11/06 08:38 |
Good luck | Kai Klaas | 04/11/06 09:10 |