Tghis bipolar output frame will enable the source to sink the current not keeping i regard the voltage polarity and thus will b used in applications such as bidirectional current devices and sources , test systems, high and low power frequency signal amplifiers and the thermometric coolers and window tinting. This device can operate as a power source and as a load irrespective of the voltage polarity.
Linear Technology has recently came up with LT78714 that is an 80V input synchronous PWM output controller that is a four quadrant output DC/DC controller. This device is clearly claimed to provide a transition output voltage that will b e from zero to 5A sourcing and shrinking the current capabilities henceforth. It will be away from the fact of output voltage polarity that will be regulating from zero to negative and positive volts.