Timeline for 3.3V DAC output to 50V amplification
Current License: CC BY-SA 3.0
30 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 2, 2013 at 15:08 | answer | added | artelse | timeline score: 1 | |
| May 6, 2013 at 12:03 | answer | added | Olin Lathrop | timeline score: 2 | |
| May 6, 2013 at 9:08 | answer | added | markrages | timeline score: 4 | |
| May 4, 2013 at 23:00 | history | tweeted | twitter.com/#!/StackElectronix/status/330819260605689857 | ||
| May 4, 2013 at 15:47 | comment | added | artelse | 3V Lithium cell. | |
| May 4, 2013 at 14:43 | comment | added | Dave Tweed | What's the battery voltage? | |
| May 4, 2013 at 10:42 | comment | added | artelse | @AnindoGhosh Load can be isolated as long as I get the desired potential difference. | |
| May 4, 2013 at 4:26 | comment | added | Anindo Ghosh | Can the operating load be isolated from ground, i.e. not connected to the generating circuit's ground reference in any way? Or does it need to be referenced to the same ground, directly or indirectly? | |
| May 4, 2013 at 0:55 | comment | added | artelse | The circuit is multiplexing a series of actuators that are voltage controlled (hence the DAC generated pulses). So am generating a pulse train where the actuators are switched in time. | |
| May 4, 2013 at 0:46 | comment | added | markrages | Would it be sufficient to have a continuous analog signal to represent the peak voltage, and a separate digital signal to trigger the pulses? | |
| May 4, 2013 at 0:46 | comment | added | markrages | Precision affects the design of the rest of the system. | |
| May 4, 2013 at 0:41 | comment | added | artelse | 7 bits, so fairly coarse resolution, but is sufficient. Can you elaborate on why this is important? | |
| May 4, 2013 at 0:21 | comment | added | markrages | Again, how accurate does the voltage need to be? How many bits is your DAC? | |
| May 4, 2013 at 0:04 | comment | added | artelse | Yes, the DAC generates pulses of varying voltage. | |
| May 4, 2013 at 0:01 | history | protected | markrages | ||
| May 3, 2013 at 23:52 | comment | added | markrages | Are you interested in controlling the voltage of the pulse? If so, how precise do you need to be? If not, if you just want to swing the full supply voltage, that's a much easier spec to meet. | |
| May 3, 2013 at 23:13 | comment | added | artelse | Ok, I see, didn't think about those 'extremes'. The pulses generated need to have a rise and fall time within a few µs. They need to be rather sharp needles with a 1:20 duty-cycle and a varying amplitude from 0 to 50V. Because of these requirements a transformer wouldn't be a solution for this application. Hope this clarifies it a bit more! | |
| May 3, 2013 at 22:56 | comment | added | Dave Tweed | No, not yet. For example, you are using a "DAC" to generate the pulses, which implies that you want to have some control over their amplitude. How accurate does that need to be? And if the other parameters are not critical to you, you need to state that, giving some numbers. Would it be OK if the risetime on a 50 us pulse was 20-30 us? Would it be OK to use a low-voltage amplifier driving a transformer to increase the output voltage? | |
| May 3, 2013 at 22:49 | comment | added | artelse | Regarding the questions about accuracy, rise and fall times, DAC, i don't think these are critical for the application. That is to say, some distortion is allowed. @DaveTweed this is my first post here. Do I provide enough details? | |
| May 3, 2013 at 22:34 | comment | added | Dave Tweed | If you're not going to provide the requested details -- all of them -- then the question will have to be closed as "not a real question". | |
| May 3, 2013 at 22:21 | comment | added | user16324 | What are acceptable rise and fall times?(say, measured at the 10% and 90% voltages) | |
| May 3, 2013 at 22:17 | history | edited | artelse | CC BY-SA 3.0 |
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| May 3, 2013 at 21:57 | history | edited | artelse | CC BY-SA 3.0 |
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| May 3, 2013 at 21:41 | comment | added | Andy aka | I'm presuming you have a power supply that is between 54V and 60V - what are the losses in generating it - is it regulated - what are the losses in the regulator? If it isn't regulated you are in danger of either not producing 50Vpk or exceeding the OP551 max rails with ac supply variations | |
| May 3, 2013 at 21:39 | comment | added | Kaz | Also, don't think that you absolutely use an op amp whose data sheet says that it's for single supply operation. Any op-amp can be used on single supply, with the appropriate care, like generating a stable V/2 reference that tries to preserve a good PSRR. I think that the key difference in an amp which is "for single supply use" is that its common mode range behaves well near, or at, the negative rail. A dual supply amp that can only go within 2V of the negative rail will cause difficulties in some single supply uses, obviously. | |
| May 3, 2013 at 21:38 | review | First posts | |||
| May 3, 2013 at 21:50 | |||||
| May 3, 2013 at 21:31 | comment | added | Dave Tweed | ... How wide are the pulses? What kind of fidelity do you expect at the output? Most importantly, what would you consider to be a reasonable power budget in this application? | |
| May 3, 2013 at 21:29 | comment | added | markrages | What accuracy is the DAC? Actually, what accuracy do you need for the 50V output? What frequency are the pulses at? Watch out for slew-rate limitations in low current opamps. | |
| May 3, 2013 at 21:24 | comment | added | Kaz | You're working with 50V swings, but 7mA is too much current from the amp? 50V: but what is the load? Across what kind of impedance does 50V have to be produced? | |
| May 3, 2013 at 21:22 | history | asked | artelse | CC BY-SA 3.0 |