T3STY
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I need to design a split power supply starting from a single power supply. The single power supply is supposed to be 24V (at least 2A) so as to have a perfect 12-0-12 split supply, but I'd like to be able to use even one as low as 19V (still 2A minimum).
The required output power of the split supply is at least 9V@1A each.
I have searched the web for designs and seems all of them have pros and cons. Next there are the two designs that convinced me the most.
The first one is based on a resistor voltage divider and a low power opamp integrated into a IC, the TLE2426; then a buffer opamp would sustain the large output current.
This circuit is capable of driving my output power needs, but by looking on various websites people say it can only support a certain amount of capacitance on the output (that specified by the opamp manufacturer), which should not be exceeded for proper operation.
The circuit has been originally found on tangentsoft.net (LINK)
![rail_splitter_opamp.png rail_splitter_opamp.png](https://www.edaboard.com/data/attachments/53/53504-08e41429d64c5a7fcd394fa0b640f35d.jpg)
The second one is based on an unusual way of using linear voltage regulators. By wrapping two complementary voltage regulators (the famous LM317/337 or 7812/7912 ect.) into a voltage divider circuit, their regulation output will maintain a nice and stable voltage for each line. Their joint output becomes the VGND.
This design has been originally found on head-fi.org (LINK)
![rail_splitter_VReg.png rail_splitter_VReg.png](https://www.edaboard.com/data/attachments/53/53505-debdf07b6ed3357fe00a18b164ec5c1e.jpg)
EDIT: R1 and R2 should be chosen based on the input voltage and they should provide 1.5mA through the LM336 diode
While this circuit is pretty much perfect, it heats up. Like a lot. I am able to provide a large heatsink for the regulators, but I'd like to avoid it if possible. And also, it might hide caveats that the original designer has not considered to exist in first place.
I know I can count on smart people on this forum and I'd appreciate if you could tell me if one of these is the best solution to go with, or if there are any better alternatives, and even how to make better the designs that I have posted.
Thank you very much to any one who replies![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
The required output power of the split supply is at least 9V@1A each.
I have searched the web for designs and seems all of them have pros and cons. Next there are the two designs that convinced me the most.
The first one is based on a resistor voltage divider and a low power opamp integrated into a IC, the TLE2426; then a buffer opamp would sustain the large output current.
This circuit is capable of driving my output power needs, but by looking on various websites people say it can only support a certain amount of capacitance on the output (that specified by the opamp manufacturer), which should not be exceeded for proper operation.
The circuit has been originally found on tangentsoft.net (LINK)
![rail_splitter_opamp.png rail_splitter_opamp.png](https://www.edaboard.com/data/attachments/53/53504-08e41429d64c5a7fcd394fa0b640f35d.jpg)
The second one is based on an unusual way of using linear voltage regulators. By wrapping two complementary voltage regulators (the famous LM317/337 or 7812/7912 ect.) into a voltage divider circuit, their regulation output will maintain a nice and stable voltage for each line. Their joint output becomes the VGND.
This design has been originally found on head-fi.org (LINK)
![rail_splitter_VReg.png rail_splitter_VReg.png](https://www.edaboard.com/data/attachments/53/53505-debdf07b6ed3357fe00a18b164ec5c1e.jpg)
EDIT: R1 and R2 should be chosen based on the input voltage and they should provide 1.5mA through the LM336 diode
While this circuit is pretty much perfect, it heats up. Like a lot. I am able to provide a large heatsink for the regulators, but I'd like to avoid it if possible. And also, it might hide caveats that the original designer has not considered to exist in first place.
I know I can count on smart people on this forum and I'd appreciate if you could tell me if one of these is the best solution to go with, or if there are any better alternatives, and even how to make better the designs that I have posted.
Thank you very much to any one who replies
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