| Products > Test Equipment |
| Cloning the HP3325A Option 002 - HV Output |
| << < (5/18) > >> |
| Jay_Diddy_B:
Hi, The mismatch in the input transistors Vbe, multiplied by the gain of the amplifier (x2) will appear as offset on the output voltage. I will measure the offset voltage on my clone versus the original board. I have been playing with the amplifier in LTspice. I believe that it can be made to be better than original design. It is still a work in progress, but I have attached my latest LTspice model. I have removed the protection circuit for now. I will put it back at the end. This version has a slew rate of 1600V/us. I have made the input stage symmetrical and changed the output transistors. C2 and C3 are trimmers used to optimize the waveform. This circuit could be used with other function generators to boost the output voltage. I have attached the LTspice model. Regards, Jay_Diddy_B |
| TERRA Operative:
--- Quote from: VK5RC on April 12, 2019, 01:17:59 am ---Thanks for the post, @Terra if you are ordering boards and components and can easily add another set - I would put my hand up for one set of both parts and pcb. Rob VK5RC --- End quote --- Yeah, I'll probably make a batch of 10 or so to start. Whichever design we end up making, I'll put together a bunch of kits. I'll wait a bit to see how Jay_Diddy_B's design goes and with his permission, I'll get something put together unless he wants to sort it out for his design. |
| TERRA Operative:
PCB layout V1.0 so far.... :-/O I went 4-layer as it greatly simplified layout and I have never tried 4-layer before so I figured why not? :) The components are laid out pretty much the same as the original, the traces are adjusted as needed. It'll change a little when I finalize which transistors will be used, but it's mostly there. Let me know if you see any obvious mistakes or tweaks I should do. :) |
| TERRA Operative:
Latest picture. :) Lots of little tweaks and stuff to make sure stuff fits. 99% done now. |
| SilverSolder:
--- Quote from: TERRA Operative on April 08, 2019, 02:27:44 am ---Nice work. I haven't used LTspice before, I should learn it some day.. Is there a spice model for the MAT01GHZ for the dual transistor? I wonder how much of a difference it would make. --- End quote --- Apparently there is no spice model for MAT-01. Analog has in the past recommended using the model for SSM2212 instead, which is available. https://www.analog.com/en/license/spice-models?mediaPath=media/en/simulation-models/spice-models/SSM2212.cir&modelType=spice-models LTSPICE does have the MAT-02 in its standard library, it may be close enough (or an alternative). |
| Navigation |
| Message Index |
| Next page |
| Previous page |