Other Parts Discussed in Thread: TPS7H6003EVM-CVAL
Hello
We are using the TPS7H6003EVM-CVAL in a test setup for Half-Bridge isolated DC/DC converter.
Power is limited by C1 and C2. At full load the voltage across each capacitor will ideally swing between Vin/2 and gnd (discharge curve)
At the secondary side, a control circuit is monitoring the output voltage across C4, activating the switching element according to a set hysteresis. Initial measurements show (not surprisingly) a large ripple voltage (approx. 12%) at point A (with no filtering installed). This voltage is increasing as a function of Vin and of course the load.
I am suspecting that the switching transistor is driven in and out of saturation, due to heavy ripple/noise on the collector-side. As a result the efficiency of the regulator is reduced with increasing voltage difference between point A and Vout.
We are looking for a bit of help when it comes to choosing values for a filter at point A, while maintaining the “constant power function” of C1 and C2.
Other design pointers and tips would also be appreciated
Thank you.
Best regards
Jonas
