Is this the elusive “DC-DC power transformer?
Some types of modern systems require a device that allows bidirectional power flow, the equivalent of a “DC-DC power transformer:” In hybrid and electric vehicles bidirectional converters can charge a low voltage (12 V) battery during normal operation and reverse the current flow to charge the high-voltage (400 V/600 V) battery.
In fact, any application where there is energy storage and energy recovery – from an electronic load that can also function as power supply -- can benefit from using bi-directional components.
One way to create bidirectional current flow is by using two “anti-parallel” converters. A more elegant, compact and energy efficient solution is to use “synchronous rectification;” turns out that most switching regulator topologies can be made to move power in either direction by replacing all diodes with low on-resistance MOSFET switches that are appropriately turned on and off under the control of a microcontroller.
This reference design for a bidirectional 400V-12V, DC-DC converter could be a good place to learn how to use bidirectional products. A phase shifted full-bridge (PSFB) with synchronous rectification controls power flow from a 400V bus/battery to the 12V battery in step-down mode, while a push-pull stage controls the reverse power flow from the low voltage battery to the high voltage bus/battery in boost mode. Read More... goo.gl/g7oAxy