Other Parts Discussed in Thread: CSD17484F4, , CSD15380F3, CSD13380F3, CSD25480F3, CSD25310Q2, CSD13202Q2
In order to enable a low-cost, high volume ultrasound application for industrial NDT, I am investigating if I can switch a pair of P/N-ch. MOSFETs (high-side PMOS and low-side NMOS) fast enough with an FPGA directly to avoid having a discrete driver IC.
The pulser would be a MAX 10 FPGA. The gate drive voltage would be 2,5V or 3,0V and at most the current will be a few hundred milliamps with a number of paralleled FPGA output pins.
Since the pulser voltage (PMOS source) is also the supply voltage, the MOSFETs need low Rds(on). There is no hard limit, but lower is better since this enables a higher pulse current for a better ultrasound signal. A fast rise time is however still more important than the on resistance.
I imagine that the high-side P-ch. MOSFET will switch something like a 10 uF MLCC to the transducer of something like 1 nF. The low-side N-ch. will switch back to ground.
The attached schematic shows the conventional, expensive, way that we would otherwise do it. I'm hoping to do away with the driver and extra power supply.
Could you suggest a pair of MOSFETs, either discrete or in a dual package, to switch most quickly?
I tend towards CSD25484F4 and CSD17484F4, due to low gate charge and on-resistance, but I am not an expert on MOSFETs, so I could be overlooking something.
