The module creating a symmetrical power supply for analog constructions with operational amplifiers (e.g. SDRXO1B receiver). The input voltage should be +12V or +5V and output respectively -12V and +12V.

One of the possibilities, how to create a negative voltage, is to use a charge pump. There already exist specialised integrated circuits suitable for this purpose.

• LTC3260

One of the limitations of the charge pump is the impossibility to obtain larger supply currents. The problem can be solved using a transformer and wiring, that will convert the input DC voltage to AC. Given that the converted voltage can be of significantly higher frequency than the usual 50Hz, the size of the transformer, having the same output, can be much smaller. The higher frequency also allows to reduce the smoothing capacity.

Moreover, in the case of input DC potential commuting sinusoidally on the transformer windings, the possibility of noise emission is considerably decreased compared to the conventional SMPS.

Another advantage in using the transformer is, that the output power supply can be galvanically isolated from the input power supply.