Split Rail Power Supply

Figure 2 is a plot of the input current versus the output current for the circuit in figure 1.

Split rail power supply.

Tps65133 5 v 250 ma dual output power supply datasheet rev. Splitting a rail using the voltage reference will often mean compromising a bit on the symmetry of the split for example if a 3v3 rail is to be split then the closest would be to use the 1 8v output reference which gives a 1 8 1 5v asymmetrical supply. Only the ref3318 is available with a 1 8v output so it could be used. The positive supply rail is created from a standard off the shelfcoupled inductor from coilcraft.

The top three ways to split a voltage rail to a. The split rail power supply uses a wide input voltage step downregulator as an inverting power supply to create the negative supply rail. In a split voltage power supply application the analog circuit is connected between the positive voltage rail and the negative voltage rail. Basic calculation of an inverting buck boost power stage rev.

Another popular inductive split rail solution is a fly buck topology which is a step down synchronous buck converter with a coupled inductor in the feedback loop. Dual power supply rails are very useful when working with op amps as this type of design provides greater stability. Understanding undervoltage lockout in power devices rev. Operational amplifiers may use a 12 v power supply rail and they operate with input and output signals that are typically dual polarity in nature similar to the sine waves or sinusoidal waves which have alternating polarity like alternating current ac.

The power supply rail used for most analog circuits still requires a split power rail.