Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

[bigpandahk]

Originally Posted by hochopeper

I think he's actually running +/- ssrlv to power the legato and a single +ve salas shunt to the VD terminals on the BIII which then feeds all 3 tridents. That was why I got confused when I first only saw 2 shunt regs (didn't spot the one hiding on the side) because powering BIII from the same supply as +ve rail to the legato would be a bit ......

Thanks hochopeper, I find the legato under the BIII.

[CeeVee]

That's right I'm doing the same ie: one BIB at 5,25 V and in excess of 0,5A to power the BIII and tridents.

The resistor gets hot but a small heatsink takes care of the transistors.

The final product with independent digital PSU and analog PSU is another matter as the digital module has 4 BIBs for the BIII, FIFO, USB-I2S module and accessories so it should get a little hotter.

I redesigned the BIB PCB for this case so i could make the thing more compact...we will see if it's feasible, here is a peak..

[qusp]

hmm, seems to me certain elements of the BIII and fifo are analogue... the master XO board from the fifo, the 9018's DVDD L/R and AVCC L/R pins are analogue mechanisms and should be treated as such IMO. the model is looking good though, I see you are taking cues from the firstwatt heatsinks? nice

[bigpandahk]

Originally Posted by CeeVee

The final product with independent digital PSU and analog PSU is another matter as the digital module has 4 BIBs for the BIII, FIFO, USB-I2S module and accessories so it should get a little hotter.

I redesigned the BIB PCB for this case so i could make the thing more compact...we will see if it's feasible, here is a peak..

You remind me another BIB for the FIFO.

Your case look like a UPS

[qusp]

is it really worth powering the fifo with shunt regs? I can understand powering the flipflops and clocks with their own dedicated shunts directly, but powering the whole thing with shunts when all the consumers on the fifo board have dedicated IC regs seems like creating a lot of heat for not much benefit.

[iancanada]

Originally Posted by bigpandahk

Hi Ian

I am also planning to use the SalasShuntReg to power the BIII. Just want to confirm my understanding is correct, you use 3 SSRLV to power the 3 trident and each set at 5.25V 100mA output? With such small current, why it generate so many heat (60 deg)???

Because the heatsink is facing down, but the hot air goes up . I'm gonna add more heatsinks and make them facing up. Hopefully I can get the stable temp around 50C.

[CeeVee]

Originally Posted by qusp

hmm, seems to me certain elements of the BIII and fifo are analogue... the master XO board from the fifo, the 9018's DVDD L/R and AVCC L/R pins are analogue mechanisms and should be treated as such IMO. the model is looking good though, I see you are taking cues from the firstwatt heatsinks? nice

Actually just using heat sinks from old Barko 2K x 2K screens...i work in air traffic control :-)

[CeeVee]

Originally Posted by qusp

is it really worth powering the fifo with shunt regs? I can understand powering the flipflops and clocks with their own dedicated shunts directly, but powering the whole thing with shunts when all the consumers on the fifo board have dedicated IC regs seems like creating a lot of heat for not much benefit.

Probably right thanks for the head's up.

[qusp]

cool, well the sinks look nice enough though, I do like that angled fins look.

do what suits, but yeah I think I would either just use batteries and be done wit it, a basic but quality linear supply, or all out and supply the main board with linear and selected parts with shunts directly. powering the whole board is a bit of current and most of the benefits of shunt regs dont really apply when there is other regs in the way. the low impedance and high bandwidth makes little or no difference and sense/force lines dont have access to the loads. of course do what sounds good to you, but the heat created by a 500-600ma shunt is not insignificant, I would want to make that count.

[bigpandahk]

Originally Posted by qusp

cool, well the sinks look nice enough though, I do like that angled fins look.

do what suits, but yeah I think I would either just use batteries and be done wit it, a basic but quality linear supply, or all out and supply the main board with linear and selected parts with shunts directly. powering the whole board is a bit of current and most of the benefits of shunt regs dont really apply when there is other regs in the way. the low impedance and high bandwidth makes little or no difference and sense/force lines dont have access to the loads. of course do what sounds good to you, but the heat created by a 500-600ma shunt is not insignificant, I would want to make that count.

It is really great that we can have this kind of advice from an expert member like you. This save us lot of time and money. I will try linear PSU or rechargeable battery to power the FIFO.