Other Parts Discussed in Thread: CSD87588N, , CSD87333Q3D, CSD88584Q5DC, CSD87353Q5D, CSD87334Q3D
I am investigating using 2 of the LM5105 half bridge gate drivers for a full bridge coil drive circuit (see schematic sketch). For the bridge FETs, I'm looking at the CSD87588N dual N-channel part. Some of the parameters of the circuit are as follows.
- Vdd and bridge supply voltage = 14V
- PWM input = 327kHz (0 - 100% duty cycle)
- Output drive waveform = sinewave
- H-bridge load = 22uH to 160uH wire wound ferrite core inductor
- H-bridge currents = 18A pk-pk
- H-bridge power dissipation = 1.5W
- This circuit is used to generate an AC magnetic waveform
Questions
- What determines whether you need to add the optional external bootstrap diode?
- The forward voltage drop of the internal diode is fairly high. If we have room on the board, is it preferable to add a fast low voltage drop external diode?
- Is the CSD87588N FET a good choice for this application?
- I am not as familiar with dual N-channel FET parts where the high and low sides have different specifications.
- We currently use a Vishay Si7218DN dual FET in a similar H-bridge application, but this part is currently listed as EOL.
- Do you see any issues with driving the gate of the CSD87588N FET with 14V. The maximum gate drive voltage (Vgs) listed in the datasheet is only 16V.
Thank you for your help -
Scott