Bipolar PI design

[algan]

Hi, Carl what would the circuit look like if a TX was built with SPDT gate drivers

[ivconic]

Last update based on Carl's corrections (click to enlarge):

[ivconic]

[Carl-NC]

I've moved the PI-GB discussion to a separate thread.

I have only just ordered a "final" PCB to build & test the bipolar design. You can wait for me to verify, or you can take the risk and start one yourself. I don't expect any major problems as I tested the design on a patched PCB and it was working fine. The only risk is if I missed any of the patch mods in the latest design.

[ivconic]

...

[ivconic]

[Carl-NC]

The latest schematics, Gerbers, and code will always be posted in relevant ITMD3 forums. I will probably keep all revisions posted (assuming there are future changes) so that you can get any version you want.

C13 can be just about anything, 10n-100n is fine. It's just a noise filter for the pot.
C23 can be 10p-33p, or left out (as it is in the book schematic). It's also a noise filter (R13-C23), but you want it faster than R9-C14.
Q7 is NPN, 3904. Another book schematic error.

[ivconic]

In the meantime you changed some components... some 100k resistors are now 47k, ok, I can't figure out which is the correct schematic now. Among other things; I need clarification on:
1) C13
2) C23
3) Q7 (3906 on schematic in the book, 3904 in recent schematics)

[Carl-NC]

I use Easy-PC. Here are the CAD files:

Pulse5_EasyPC.zip

[algan]

Thanks, Carl, can you tell me what program the file was made with? I want to import the Gerber file. I assume the program will be able to do it.

[Carl-NC]

It is a gap in the ground plane to isolate TX/digital ground noise from the RX.

[algan]

Hello, Carl, I want to ask you, what exactly is this path colored white here for it probably cuts off the back side, but isn't it still connected? Thank you.

[Op04]

This is amazing breakthrough ...thank you so much Sir Carl

[Carl-NC]

I've just posted the schematic & PCB for the Bipolar PI design. I will post the source code as soon as I clean it up.

[ivconic]

To my pleasant surprise, I found a whole series of drivers at a local store: TC426, TC427, TC428 and TC429.
The prices are quite affordable.
Now it's a matter of pure tradeoff arguments between a couple of discrete mosfets and this kind of driver.
4 discrete mosfets in a SOT-23 package take up less space on the pcb.
(SOT-23 is something I still manage to solder to the pcb)
But the driver chips should work better.