Other Parts Discussed in Thread: TINA-TI
Tool/software:
Dear Engineers,
I'm using the TI reference design to design a variable output voltage from +/- 5 to +/- 60V, I have a ultrasound device the will be the load for the mentioned DC-DC convertor, the electrical model for the load can be models as follows:
After simulation I noticed there will be around 8-10 A transient current that the load will draw:
In the simulation file there are 4 time-based switches that will connect the load to the positive voltage rail as follows:
Every 4 pulse is considered as one cycle in the ultrasound measurement. I expect after this four cycle the voltage will drop a bit, but I look for recovery of the voltage in a very short time (2-3 ms).
I simulated the circuit with 1uF capacitor output, the results are as follows:
It means the 1uF capacitor is not enough for that transient current, then I increase the capacitor and I noticed the higher the capacitor the more stable the output waveform:
For example for 47uF:
I did the simulation even with 68uF, then I noticed the settling time for the output voltage will increase by increasing the capacitor:
So my question is what is the best trade off to have a stable circuit for this load and still be fast enough (2-3 ms) to be able to recover the voltage after each load cycle?
TINA-TI files:
Regards,
