Hi audionootje,
currently I'm on holiday, but I am coming back this saturday. From next week these PCBs will be again available.
Best regards,
Aleš
Ales
Is that the size of the dual board or single?
I sent you a PM re my intended implementation.
That is the size of single PCB. Dual PCB mounting plan is attached in this reply. As said the simplest way to make holes for PCB is to print attached file in 1:1 ratio. Then attach paper to the surface where you want to mount PCBs, mark holes and drill them.
best regards,
Aleš
Hi Bart,
I have a couple of these (TPS7A8300) available. Drop me PM.
Best Regards,
Aleš
Hi Aleš
I'm looking for a regulator design that offer output voltages up to 38Vdc and up to 100 to 150 mA.
Have you any regulator boards/designs that offer this higher voltage or recommend any power supply designs that you know of that offer the same low noise characteristics as your TPS7A4700?
Thanks
I'm looking for a regulator design that offer output voltages up to 38Vdc and up to 100 to 150 mA.
Have you any regulator boards/designs that offer this higher voltage or recommend any power supply designs that you know of that offer the same low noise characteristics as your TPS7A4700?
Thanks
derekr, please find attached PDF with measurements. Output pads have 5.08mm spacing.
marcus1 I do not have any regulator to achieve such high voltage, though you could still try to parallel two regulator each at 19V to achieve 38V.
Best Regards,
Aleš
Hi folks.
I'm fiddling around with a ES9023 DAC (MamboBerry) - I'm running also a related thread over here.
As AVDD a LP5907 with <6.5uV noise (datasheet) is used on the MamboBerry.
(Which is not that bad considering effort and cost.)
Until now I used Ales LDO powered by 6.8V LiFePO4 as pre-LDO to supply 5V to that LP5907.
Now I want to (and can) introduce just a single regulation stage.
Ales LDO has a little better noise performance on paper (4uV datasheet) then the LP5907.
BTW: Ales you added another inductor on the output. Was your plan to get the noise even further down then the theoretical 4uV of the TPS? Did yo manage? ( I do know that this would be very challenging to measure)
Obviously the AVCC pin right at the DAC chip is most critical.
Several inmates including me figured out that different types of buffer caps right in front of the DAC have quite an impact on perceived soundquality.
People go as high as 560uF with this or that boutique cap. I'm running currently 2*33uF Blackgate BG-Ns.
Finally my question.
Ales has some buffer caps , 33uF ? , on the board behind the LDO already.
I'm wondering if it would be better to remove these to avoid some kind of interference with the Blackgates. Stacking all kind of caps might not be a good idea!??
The TPS datasheet also says best noise performance is achieved at 50uF load. I might do better with just 2*33uF BG-N only.
Another Q just hit my mind:
Does it make sense to put the TPS sensing pin between DAC-AVCC input and cap buffer?
Any advice for the best possible implementation for Ales LDO at this (such a) spot are highly appreciated.
Thx
I'm fiddling around with a ES9023 DAC (MamboBerry) - I'm running also a related thread over here.
As AVDD a LP5907 with <6.5uV noise (datasheet) is used on the MamboBerry.
(Which is not that bad considering effort and cost.)
Until now I used Ales LDO powered by 6.8V LiFePO4 as pre-LDO to supply 5V to that LP5907.
Now I want to (and can) introduce just a single regulation stage.
Ales LDO has a little better noise performance on paper (4uV datasheet) then the LP5907.
BTW: Ales you added another inductor on the output. Was your plan to get the noise even further down then the theoretical 4uV of the TPS? Did yo manage? ( I do know that this would be very challenging to measure)
Obviously the AVCC pin right at the DAC chip is most critical.
Several inmates including me figured out that different types of buffer caps right in front of the DAC have quite an impact on perceived soundquality.
People go as high as 560uF with this or that boutique cap. I'm running currently 2*33uF Blackgate BG-Ns.
Finally my question.
Ales has some buffer caps , 33uF ? , on the board behind the LDO already.
I'm wondering if it would be better to remove these to avoid some kind of interference with the Blackgates. Stacking all kind of caps might not be a good idea!??
The TPS datasheet also says best noise performance is achieved at 50uF load. I might do better with just 2*33uF BG-N only.
Another Q just hit my mind:
Does it make sense to put the TPS sensing pin between DAC-AVCC input and cap buffer?
Any advice for the best possible implementation for Ales LDO at this (such a) spot are highly appreciated.
Thx
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Hi soundcheck,
on the output there is ferrite bead from Wuerth, with 100nF cap creates LC filter. As you already said it is used to reduce the output noise and most importantly to achieve better sound quality. A lot users of the first version TPS7A4700 regulator stated the sound with this regulator is harsh. Ferrite bead relaxed it, making it more enjoyable.
Output noise was measured a few times by Kingpin, but he measured old version of the PCB. I am planing to acquire measurement device to get some measurements done.
If you remove ceramic capacitors and replace them with BG caps you will have higher ESR and ESL becuase of the longer leads and cap characteristics. Listening tests showed that 10uF capacitor across ceramics is enough to change the sound of the regulator.
If you plan to use sensing, use it as close as possible to the AVCC pin. Try it with and without buffer caps. What will perform better in terms of sound quality you'll need to find out by yourself.
BR,
Aleš
on the output there is ferrite bead from Wuerth, with 100nF cap creates LC filter. As you already said it is used to reduce the output noise and most importantly to achieve better sound quality. A lot users of the first version TPS7A4700 regulator stated the sound with this regulator is harsh. Ferrite bead relaxed it, making it more enjoyable.
Output noise was measured a few times by Kingpin, but he measured old version of the PCB. I am planing to acquire measurement device to get some measurements done.
If you remove ceramic capacitors and replace them with BG caps you will have higher ESR and ESL becuase of the longer leads and cap characteristics. Listening tests showed that 10uF capacitor across ceramics is enough to change the sound of the regulator.
If you plan to use sensing, use it as close as possible to the AVCC pin. Try it with and without buffer caps. What will perform better in terms of sound quality you'll need to find out by yourself.
BR,
Aleš
I'm pretty sure I won't forget about noise.
Noise sets the natural limit of your DAC resolution. Already 10uV vs 5uV would mean 1 bit (= 19 vs. 20bit) difference. (LT3042 = 0.8uV noise = 22 bit - Ales -- your next project??).
Especially for people like me who are running digital volume control only, noise got a tiny bit of relevance.
There got to be a deeper sense in your comment though. Please shed some light on your frequency linear impedance issue.
And of course It would be nice to hear about a potential solution/approach.
Could be done with a R and C in serie over the ouput.
Double the RC parallel with difference values for lower frequency en higher frequency to lower the impedance values for the output.
I have some schematics if you want.
PM sent already but i see that i can attach an attachment here (not working in pm).
I hope this is what you or others are looking for.
Best regards