Looks like oscillation to me. What happens if you will stick 100uF directly across the sense lines?
Nothing really.... still same noise/oscillation
- Please note that my regs share a groundplane with their load (tda1541a). The S0 and F0 are directly connected to the gnd plane. I don't think this should create these oscillations, but may be worth mentioning.
- I am using a 220uF nichicon for C201, and a 3.3uF Wima for C204
- C203 and C202 are unused
- Please note that my regs share a groundplane with their load (tda1541a). The S0 and F0 are directly connected to the gnd plane. I don't think this should create these oscillations, but may be worth mentioning.
- I am using a 220uF nichicon for C201, and a 3.3uF Wima for C204
- C203 and C202 are unused
Sorry not (+) in this case, at the (-)V node that your application feeds. Where the -F, -S go.
I put a 1R0 in series with the output, this reduces the amplitude of the oscillation (to about 20mVpp when loaded)....
Can someone please confirm to me that the following applies to the Salas 1.2R circuit diagrams in post 3200 on page 320.
Q8 (2n5457) gate and drain are tied and connected to the collector of Q7 (BC550C) in the positive versions. In the negarive versions the gate and drain of Q8 are still tied, but this time connected to the negative output.
There is no Drain labelled in the negative circuits and I don't want to get the orientation (or my PCB) incorrect.
Q8 (2n5457) gate and drain are tied and connected to the collector of Q7 (BC550C) in the positive versions. In the negarive versions the gate and drain of Q8 are still tied, but this time connected to the negative output.
There is no Drain labelled in the negative circuits and I don't want to get the orientation (or my PCB) incorrect.
Hi Salas,
Not exactly sure what you mean, but these are the caps I use:
- I am using a 220uF nichicon for C201, and a 3.3uF Wima for C204
- I am using a 1uF decoupling cap right at the load <-- I guess that's what you mean, it's an acrylic film cap 🙂
- C203 and C202 are unused
Not exactly sure what you mean, but these are the caps I use:
- I am using a 220uF nichicon for C201, and a 3.3uF Wima for C204
- I am using a 1uF decoupling cap right at the load <-- I guess that's what you mean, it's an acrylic film cap 🙂
- C203 and C202 are unused
Q8 Gate & Source are tied to the Q7 collector in the positives. Gate & Source are tied to the (S-) rail in the negatives.
That's it! Removing the acrylic at the load solved the problem...
Can you explain what happened here? I would like to understand also what the possibilities and limitations are on local decoupling...
Can you explain what happened here? I would like to understand also what the possibilities and limitations are on local decoupling...
+70VDC/-70VDC
Hi Guys, is there any way to get +/-70VDC about 100mA load using the SSLV?.
Quan
Hi Guys, is there any way to get +/-70VDC about 100mA load using the SSLV?.
Quan
It was neutralizing the Zobel termination, throwing away much phase margin.
Big discussion the local decoupling thing... Not very near where the reg feeds and always use your scope, in short.
Mmm... could be a problem in digital circuits, no? IIRC, the reg has very low impedance up to 200kHz, but it rapidly rises above that. Some local decoupling will be required on digital...
Its ~0.1 Ohm @ 1MegHz with your 9620/620s. Has to be checked and tuned as a single system the local & the reg's compensation. Most are stable as it is, others are not.
My p2p BiB is working steady as a rock... Thank you Salas for the perfectly clear instructions in the pdf and Merlin for the fets.
I am using a Block TX with double secondaries (2 x 15Vac) to produce 14Vout from the BiB.
I am only using one winding and would like to parallel the second winding to lower output imp of the TX.
The TX has four wires coming out in the following order: Black, Red, Yellow, White
Black and Red form one 15Vac winding, Yellow and White form the other.... how should I connect them to get 15Vac out with double current capacity ?
I am using a Block TX with double secondaries (2 x 15Vac) to produce 14Vout from the BiB.
I am only using one winding and would like to parallel the second winding to lower output imp of the TX.
The TX has four wires coming out in the following order: Black, Red, Yellow, White
Black and Red form one 15Vac winding, Yellow and White form the other.... how should I connect them to get 15Vac out with double current capacity ?
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