Introduction
I want to present you my latest idea, open source power supply modules called OLDO. The name stands for Open LDO = OLDO. The whole project is around small PCB modules which contain various LDOs. Now we all like to experiment how power supply effects the end result, that is sound. And a lot of times there is quite big hassle to change PSU, especially when we already have everything mounted into the enclosure. So why not just change the core, regulator, and not the whole power supply? In the matter of minutes you'll be able to hear new regulator in action. These interchangeable PCBs are called Module A and their size is 20x26mm. Currently I made two versions of it one with TPS7A4700 and one with two LT3045 regulators in parallel. Both modules are capable of 1A current. They contain the basic parts for regulators to work properly. Connectors are standard 2.54mm pin headers and their alignment is arranged so they can be mounted on standard prototype PCB. Modules accept DC voltage input. Now any user can make his own AC/DC conversion or just DC input, and post filtering of the regulator. One with some experience in PCB design can even make support PCB to his own needs.
Till today I developed two Modules A and one support PCB called motherboard RMP (ready made power). Specs and options are listed under each device.
Module A
TPS7A4700 Module A
Size: 20 x 26 [mm]
Vin: DC max 25V, limited by rating of components
Vout: DC 1.4V -> 21V(max), limited by LDO
Iout: max 1A
Noise: 4uV
Sensing: Yes
Datasheet TPS7A4700 LDO
LT3045 parallel Module A
Size: 20 x 26 [mm]
Vin: DC max 20V, limited by LDO
Vout: DC 0V -> 15V(max), limited by LDO
Iout: max 1A
Noise: 0.8uV, theoretically even lower due to paralleled LDOs
Sensing: No
Datasheet LT3045 LDO
Motherboards
Ready made power - RMP
Size: 93 x 38 [mm]
AC or DC voltage input (separate inputs)
CLC input filter
LC output filter
Supports sensing
Option for THT and SMT diodes
Option for screw and spring load connectors
Github repository
OLDO - Open LDO
All new files will be now posted on the GitHub
I want to present you my latest idea, open source power supply modules called OLDO. The name stands for Open LDO = OLDO. The whole project is around small PCB modules which contain various LDOs. Now we all like to experiment how power supply effects the end result, that is sound. And a lot of times there is quite big hassle to change PSU, especially when we already have everything mounted into the enclosure. So why not just change the core, regulator, and not the whole power supply? In the matter of minutes you'll be able to hear new regulator in action. These interchangeable PCBs are called Module A and their size is 20x26mm. Currently I made two versions of it one with TPS7A4700 and one with two LT3045 regulators in parallel. Both modules are capable of 1A current. They contain the basic parts for regulators to work properly. Connectors are standard 2.54mm pin headers and their alignment is arranged so they can be mounted on standard prototype PCB. Modules accept DC voltage input. Now any user can make his own AC/DC conversion or just DC input, and post filtering of the regulator. One with some experience in PCB design can even make support PCB to his own needs.
Till today I developed two Modules A and one support PCB called motherboard RMP (ready made power). Specs and options are listed under each device.
Module A
TPS7A4700 Module A
Size: 20 x 26 [mm]
Vin: DC max 25V, limited by rating of components
Vout: DC 1.4V -> 21V(max), limited by LDO
Iout: max 1A
Noise: 4uV
Sensing: Yes
Datasheet TPS7A4700 LDO
LT3045 parallel Module A
Size: 20 x 26 [mm]
Vin: DC max 20V, limited by LDO
Vout: DC 0V -> 15V(max), limited by LDO
Iout: max 1A
Noise: 0.8uV, theoretically even lower due to paralleled LDOs
Sensing: No
Datasheet LT3045 LDO
Motherboards
Ready made power - RMP
Size: 93 x 38 [mm]
AC or DC voltage input (separate inputs)
CLC input filter
LC output filter
Supports sensing
Option for THT and SMT diodes
Option for screw and spring load connectors
Github repository
OLDO - Open LDO
All new files will be now posted on the GitHub
Attachments
Last edited:
Heat sink
These modules are small and one might think how it will be able to handle current of 1A. I came to the solution which makes heat sinking of these modules quite simple. Instead of being placed at the top of the support PCB it must be placed at the bottom of it. The thermal bridge between module PCB and larger cooling surface is established with thermal pad.
The height from bottom side of the motherboard to the bottom of the module is just a bit under 11mm. I used 12mm standoffs and 1.5mm thick thermal pad, providing just enough pressure for good thermal contact.
These modules are small and one might think how it will be able to handle current of 1A. I came to the solution which makes heat sinking of these modules quite simple. Instead of being placed at the top of the support PCB it must be placed at the bottom of it. The thermal bridge between module PCB and larger cooling surface is established with thermal pad.
The height from bottom side of the motherboard to the bottom of the module is just a bit under 11mm. I used 12mm standoffs and 1.5mm thick thermal pad, providing just enough pressure for good thermal contact.
Attachments
I wonder if somebody could advise what is the best way of outputting 1.2V say 400mA from the LT3045 module? Is there a neater way than adding a second in series LDO? Preferably one would want to retain the low noise output of the LT3045? The new ESS dac chips require 1.2V.
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Do you mean the TPSA47 pcb? The minimum voltage for that regulator is 1.4V according to the datasheet?
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Can you go ahead and solder the voltage set resistors on this board if I purchase one? I would like 12VDC outputs.
LT3042 DUAL power supply DAC preamplifier headphone amplifier
Thanks.
LT3042 DUAL power supply DAC preamplifier headphone amplifier
Thanks.
Sorry must have been having a bad day! Output voltage can be anywhere between 0 and 15V no problem.[emoji846]
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Minimum output voltage is 1.4V which is also the refference.
Yes, I can. I think that is also said in the ebay add.
Best Regards,
Aleš
The way you word it in the Ebay ad is why I was confused.
"Output voltages are set with 0805 resistor (in package are resistors included for 3.3V, 5V, 12V)"
This sounds as if various resistors are included with the board so people can select and solder the one they require.
No problem...I read more into it than needed.
Thank you for your reply.
The way you word it in the Ebay ad is why I was confused.
"Output voltages are set with 0805 resistor (in package are resistors included for 3.3V, 5V, 12V)"
This sounds as if various resistors are included with the board so people can select and solder the one they require.
No problem...I read more into it than needed.
Thank you for your reply.
Hi, thank you for your feedback. I have to admit, but you're right. It is not clearly stated buyer can get configured PCB. I will fix that.
BR,
Aleš
You're welcome.
I admit that sometimes even simple things can confuse me and I'm just not able "to see the forest for all the trees".
I look forward to receiving and trying your LT3042 dual supply.
I received my LT3042 dual supply board a few days ago.
The PCB layout and the soldering of all the SMD's were all first-rate.
After soldering the few thru-hole components included with the board, it worked the first time without any issues whatsoever.
Plus...I didn't have to wait 2 or 3 weeks to receive the board and components like you do with most Chinese sellers.
I hope I can try the LT3045 in the near future if you offer a dual version on Ebay like you did for the '3042.
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