Fly Back Converter with Feed - Forward Control and TPS3700 based Protection Scheme for Fast Transient Space Applications

A composite controller fly back topology is proposed for the low voltage, high current (20W) DC - DC converter applications. The controller developed is intended to be used in high performance applications and yet keeping a simple configuration. It combines the feature of Feed - forward and direct sense magnetic coupled feedback control techniques. It also has TPS3700 (window comparator for over and under voltage detection which make the circuit simple and compact, save lot of space. Constant loop gain is achieved in a fly back type DC to DC converter by the use of Feedback to correct for load variation and feed - forward to correct for line voltage variation. Some characteristic provided by these controllers are: rejection of the source variation on the output voltages, better dynamic response, control loop gain doesn?t get effected by input voltage and robustness of the design. Furthermore, the operating switching frequency chosen 1MHZ which reduces the overall size and weight of the converter to increase the Power density delivered by the converter. Theoretical analysis and simulations were carried out to analyse the proposed design. The proposed design is verified with a prototype of fly back dc - dc converter fabricated for triple output configuration.