Inelectronics, asplit-pi topology is a pattern of component interconnections used in a kind ofpower converter that can theoretically produce an arbitrary output voltage, either higher or lower than the input voltage. In practice the upper voltage output is limited to the voltage rating of components used. It is essentially aboost (step-up) converter followed by abuck (step-down) converter. The topology and use ofMOSFETs make it inherently bi-directional which lends itself to applications requiringregenerative braking.
The split-pi converter is a type ofDC-to-DC converter that has an output voltage magnitude either greater than or less than the input voltage magnitude. It is aswitched-mode power supply with a similar circuit configuration to aboost converter followed by abuck converter. Split-pi gets its name from the pi circuit due to the use of two pi filters in series and split with the switching MOSFET bridges.
Other DC–DC converter topologies that can produce output voltage magnitude either greater than or less than the input voltage magnitude include theboost-buck converter topologies (the split-pi, theĆuk converter, theSEPIC, etc.) and thebuck–boost converter topologies.
In typical operation where a source voltage is located at the left-hand side input terminals, the left-hand bridge operates as aboost converter and the right-hand bridge operates as abuck converter. In regenerative mode, the reverse is true with the left-hand bridge operating as abuck converter and the right as theboost converter.
Only one bridge switches at any time to provide voltage conversion, with the unswitched bridge's top switch always switched on. A straight through 1:1 voltage output is achieved with the top switch of each bridge switch on and the bottom switches off. The output voltage is adjustable based on the duty cycle of the switching MOSFET bridge.
