Another dual mono solution of the dual XO clock board
I realize there is another solution to setup the dual mono configuration. It's much easier than the solutions I posted yesterday.
1. Remove the 7P PH2.0mm I2S output connector from the Dual XO Clock board by a SMT soldering station.
2. Assemble three u.fl sockets on the corresponding footprints. Centre pins face to the signal pads with ground pins face to the ground pads. The positions are just fit. That’s all need to do, you make itJ.
The only thing I have to mention is that all the u.fl cables need to be in same length. Because two u.fl sockets share same impendence matching resistor, you have to make the reflections arriving at the same moment.
Ian
I realize there is another solution to setup the dual mono configuration. It's much easier than the solutions I posted yesterday.
1. Remove the 7P PH2.0mm I2S output connector from the Dual XO Clock board by a SMT soldering station.
2. Assemble three u.fl sockets on the corresponding footprints. Centre pins face to the signal pads with ground pins face to the ground pads. The positions are just fit. That’s all need to do, you make itJ.
The only thing I have to mention is that all the u.fl cables need to be in same length. Because two u.fl sockets share same impendence matching resistor, you have to make the reflections arriving at the same moment.
Ian
Attachments
Indeed, any guesstimate on that?
Hardware revisions and testing and then a production version. Realistically ... don't get too impatient. These things are worth waiting for, I've heard qusp's FIFO.
Ian,
Couple of comments on the dual setup.
On your second posted solution, it seems to me that the connector pads are shorted.
You mention impedence matching but in your first post solution 1, the connections are not impedence matched. They are matched on solution 2 of the first post. This new solution does not seem to be matched either unless the wires are of equal length and the same impedence.
Would it not be better to jumper the 31 r resistors from the FF and use them at the spliced end of the connection. That would be each wire spliced to 2 x 31R to feed each of the 2 dacs. Perhaps also that this is overkill.
regards.
Couple of comments on the dual setup.
On your second posted solution, it seems to me that the connector pads are shorted.
You mention impedence matching but in your first post solution 1, the connections are not impedence matched. They are matched on solution 2 of the first post. This new solution does not seem to be matched either unless the wires are of equal length and the same impedence.
Would it not be better to jumper the 31 r resistors from the FF and use them at the spliced end of the connection. That would be each wire spliced to 2 x 31R to feed each of the 2 dacs. Perhaps also that this is overkill.
regards.
Hi necplusultra,
Please don't worry about that. They were not shorted
. Please see the gaps over the seats. Locations of solution3 are perfect.Output impedance matched to 50 ohm u.fl cable for all the solutions. Solution 2 comes with independent resistor for each cable, solution1 and 3 branch the output.
Ian
Si570 doesn't have a user flash memory to remember the last frequency, so it will go the factory default if there is no driver connected.
Driver usually has flash memory to remember the last frequency and other parameters. That's why we have to develope a MCU based driver for Si570.
Si532 can remember two frequencies, but programming doesn't open to users.
Regards,
Ian
Last edited:
Challenging low noise power supply: To design a universal battery management board
Since batteries were widely approved as one of best low noise and easy to use power supply for oscillators and other low jitter applications, I decide to design a battery management board.
I couldn't put up with battery as a testing hookup anymore. I need my battery based power supply working as standard equipment in my system. This battery management board may have the following features:
1. Comes with an on/off control interface. Could use the system power or a switch as the control signal.
2. Comes with an external charger interface
3. Compatible with different type of battery or different voltage.
4. Isolate output with charger and control circuit.
5. Pure battery operating without internal ground connection.
6. Support multi-board configure to setup battery based power supply groups.
7. Could stack on top of the clock board or stack over each other as an array.
8. Batteries from different board could share a same charger if they come with same voltage and chemical type
9. Optional battery monitoring interface
10. Simple pure passive design avoids any additional noise introduced by active components.
11. DIY friendly and many options for different applications.
12. Batteries in parallel are available.
13. Charger will be bypassed during working time.
14. Easily being integrated into system.
Any suggestions or comments?
Ian
Since batteries were widely approved as one of best low noise and easy to use power supply for oscillators and other low jitter applications, I decide to design a battery management board.
I couldn't put up with battery as a testing hookup anymore. I need my battery based power supply working as standard equipment in my system. This battery management board may have the following features:
1. Comes with an on/off control interface. Could use the system power or a switch as the control signal.
2. Comes with an external charger interface
3. Compatible with different type of battery or different voltage.
4. Isolate output with charger and control circuit.
5. Pure battery operating without internal ground connection.
6. Support multi-board configure to setup battery based power supply groups.
7. Could stack on top of the clock board or stack over each other as an array.
8. Batteries from different board could share a same charger if they come with same voltage and chemical type
9. Optional battery monitoring interface
10. Simple pure passive design avoids any additional noise introduced by active components.
11. DIY friendly and many options for different applications.
12. Batteries in parallel are available.
13. Charger will be bypassed during working time.
14. Easily being integrated into system.
Any suggestions or comments?
Ian
Attachments
Last edited:
ok so this is allowing to break the i2s ground from fifo to XO board? i'm off to bed, i'll have a think and send you some ideas and designs, like the circuits i'm using for the same purpose in my portable dac
uses ltc2935 battery monitor, adjustable thresholds for lifepo4, lipoly, low charge indication relay driver.
I use external 10 cel fast charger/balancer from FMA, the cellpro 10XP
uses ltc2935 battery monitor, adjustable thresholds for lifepo4, lipoly, low charge indication relay driver.
I use external 10 cel fast charger/balancer from FMA, the cellpro 10XP
Last edited:
Ian:
Most of the charging circuits for Li batteries are much more complex and active than a simple trickle charger. Reading through the specs I see hits of DC-DC converters which can be a major noise source. You can synchronize them with the system clocks, which gets complex when the clocks change. Linear Technologies has a decent low noise converter that doesn't regulate but is expensive to implement. You also need magnetics in this case transformers and rectifiers. It will require a lot of careful management of emi to get good results but it can be a really useful device. I would start with TI's portfolio of battery management chips. They also have a good selection of charge pumps that can be synchronized.
I started on a very similar DC management circuit for a USB audio application, not DC isolated but needing multiple split supplies. I can supply what I had done if it helps. . .
Most of the charging circuits for Li batteries are much more complex and active than a simple trickle charger. Reading through the specs I see hits of DC-DC converters which can be a major noise source. You can synchronize them with the system clocks, which gets complex when the clocks change. Linear Technologies has a decent low noise converter that doesn't regulate but is expensive to implement. You also need magnetics in this case transformers and rectifiers. It will require a lot of careful management of emi to get good results but it can be a really useful device. I would start with TI's portfolio of battery management chips. They also have a good selection of charge pumps that can be synchronized.
I started on a very similar DC management circuit for a USB audio application, not DC isolated but needing multiple split supplies. I can supply what I had done if it helps. . .
Batterie-charger:
1. I'm also running a Buffalo with LiPoFes. It would be nice to have multiple
outlets coming witch such a charger. This way you can charge your
device and e.g a DAC supply with the same charger. You just turn the
switch and all batteries are charged at the same time.
2. I'm also running bridged LiPoFes to feed a 5V regulator.
Some kind of bridging option might be nice.
Such a charger is definitely missing in the DIY word.
Cheers
1. I'm also running a Buffalo with LiPoFes. It would be nice to have multiple
outlets coming witch such a charger. This way you can charge your
device and e.g a DAC supply with the same charger. You just turn the
switch and all batteries are charged at the same time.
2. I'm also running bridged LiPoFes to feed a 5V regulator.
Some kind of bridging option might be nice.
Such a charger is definitely missing in the DIY word.
Cheers
I am joining both of you guys with this opinion. It makes all sense with internal I2S source ( USB to I2S board), but for any transportation longer than few inches benefits are lost. I2S has a clear advantage when conversions to and from S/PDIF are voided and that is where popularity stems from. But, short distance requirement, coupled with need for very particular high quality wiring and coupling, opens up I2S as a wrong choice in many situations. As for the choice of S/PDIF signal and its integrity I would always prefer balanced approach, which kind off makes it AES/EBU.
Here is an interesting project for Si570, but more interestingly check at the bottom of the page, some very impressive measurement.
Si570 Kit from K5BCQ
Si570 Kit from K5BCQ
Hi Demian,
I don't need the battery being charged while it's powering the oscillator. So, I think all the functions could be implemented by a DPDT relay
. I will use a standard external charger or a trickle charger and will disconnect it if the battery power is on. I'm trying to make a very simple design with all passive components to avoid introducing EMI noise. Just to see if I could.
Regard,
Ian