Hello everyone,


I’m looking for a way to generate a symmetric ±12V power supply without using a transformer.
Can you recommend any modules or ICs that can provide ±12V output from a single DC input?


My goal is to keep the circuit simple and reliable. Any suggestions would be greatly appreciated.

 

How much current is required?
What is the DC input?

 

Hi 1231,
Welcome to AAC.
What current levels are required?
E

 

How much current is required?
What is the DC input?

DC in put 12V
current i think 100mA or 200mA

 

there are only two passive elements that store energy - inductors and capacitors.
if you need isolation, you NEED transformer.
if you do not need isolation you can use either inductor or capacitor based switching mode regulators. the ones using inductors are more common and allow for more flexibility.
ones using capacitors as storage are typically used for low power and specific voltage such as RS232 drivers etc.
right now i am using capacitor based switcher LM2776DBVR to get -5V from +5V for my OpAmps so they can get to 0VDC (or below). this works for low voltages 2.7-5.5V and max load current of 200mA. on the other hand, you can get ready made modules that do exactly what you want and are small and relatively low cost (at least in small volume).

for example 12V*2*0.2A is about 5W but you need to be specific what you need. isolated or not, regulated or not, etc.

 

https://www.digikey.co.uk/en/products/detail/traco-power/TIM-3-5-0922SM/9383078
or similar

 

https://www.digikey.co.uk/en/products/detail/traco-power/TIM-3-5-0922SM/9383078
or similar

Has a transformer inside it. This is what I use. It does not regulate well. They do work.

 

We've been using Polytron DC-DC converters for 40-ish years. A bit pricey, but extremely reliable. The TWA8-12-12 might work for you.

 

@Quang1231

what do you mean by no transformer ?
no metal at all., even inside the package , or just you dont want to provide a transformer yourself ?
as you see above, there are many modules that do what you want, but they probably all contain coils / transformers inside the case.

 

@Quang1231

what do you mean by no transformer ?
no metal at all., even inside the package , or just you dont want to provide a transformer yourself ?
as you see above, there are many modules that do what you want, but they probably all contain coils / transformers inside the case.

Is there any type like A1212S?

 

Has a transformer inside it. This is what I use. It does not regulate well. They do work.

thanks you very much

 

We've been using Polytron DC-DC converters for 40-ish years. A bit pricey, but extremely reliable. The TWA8-12-12 might work for you.

thanks you very much

 

Is there any power module like A1212S?

 

Is there any power module like A1212S?

https://www.digikey.co.uk/en/products/detail/recom-power/RD-1212D/2303664

 

TMR 4-1222
$15.33

Input Voltage: 9~18Vdc
Output Voltage #1: 12Vdc
Output #1 Max Current: 0.166 Amps
Output Voltage #2: -12Vdc
Output #2 Max Current: 0.166 Amps
Max Power: 4 Watts

 

Most of the power modules we are talking about do not regulate the output voltage. There is a oscillator, two transistors, a transformer and diodes. If the input voltage changes the output voltage also changes. In many cases this is fine.
Some modules do regulate. There is a real PWM inside.
If the specs are 12V in 12V out there is probably no regulation. (12V in 5V out)
If the specs are 9-18V in, 12V out, then there is a real PWM inside.

 

I prefer a virtual ground, which will take 24 volts and make it a virtual ±12 Volt dual tracking power supply.

 

Thank you everyone very much
Love <3

 

Any reason no one has suggested a simple charge pump inverter? A TC1044, or LT1054, or even a TC962 might fit the requirements and be a lot less expensive, no?

 

Any reason no one has suggested a simple charge pump

200mA