Hi all,
I'm working on a MIDI synth project and have questions regarding its power supply. I want to power it from one of those 12V DC/350mA bricks I have around. I need to generate roughly +5V, 150 mA (for a microcontroller, a backlit LCD display and a bunch of LEDs / logic circuits, and the audio circuitry), 50 mA for the -5V rail (audio circuitry only). What I use so far is a resistor divider and an ersatz of high-current op-amp using an op-amp for the feedback + a push-pull: **broken link removed** . I am bit worried that this might not be the best option, because one of the transistors tends to generate a lot of heat. And this takes a lot of PCB real estate.
I have found many virtual grounds circuits online, but most of them seem to be for headphone amps where the load on the -/+ rails is equal -- so I am not sure if they would perform well with an uneven load. I'm tempted to try the TLE2426 + BUF634 + anonymous op-amp for the feedback loop, but this is a more expensive solution...
Any other approach to this problem?
I'm working on a MIDI synth project and have questions regarding its power supply. I want to power it from one of those 12V DC/350mA bricks I have around. I need to generate roughly +5V, 150 mA (for a microcontroller, a backlit LCD display and a bunch of LEDs / logic circuits, and the audio circuitry), 50 mA for the -5V rail (audio circuitry only). What I use so far is a resistor divider and an ersatz of high-current op-amp using an op-amp for the feedback + a push-pull: **broken link removed** . I am bit worried that this might not be the best option, because one of the transistors tends to generate a lot of heat. And this takes a lot of PCB real estate.
I have found many virtual grounds circuits online, but most of them seem to be for headphone amps where the load on the -/+ rails is equal -- so I am not sure if they would perform well with an uneven load. I'm tempted to try the TLE2426 + BUF634 + anonymous op-amp for the feedback loop, but this is a more expensive solution...
Any other approach to this problem?