piezo driver with DAC81404

[calvingloster]

Hi

I am in the process of designing a PCB that will drive a piezo transducer that is split into 4 quadrants. The piezo transducer will move an atomically sharp tip to probe the surface of a specimen whereby a preamp circuit will measure and amplify the tunneling current when the tip gets close to the sample.

The idea is to scan the sample in an X Y pattern to build up a height map of the surface.

My question is will the DAC81404 be adequate to directly drive the piezo transducer or will I need an additional power stage after the DAC? The piezo transducer is a general use 25mm diameter piezo disk used in cheap piezo buzzers. The piezo transducer has a capacitance of 25000pf at 1khz and a  resonant impedance of 500ohms. The DAC has an output stage that specifies a load current of 15mA when Avdd is > 5.5v. now I'm not sure if this is the correct spec to be looking at? I know that the faster I drive the piezo the more current it will require. How would I go about calculating ho much current the DAC will need to supply if Avdd is a bipolar 15v supply and I want to do 100hz scanning.

I would like to scan as many points /second as possible but would be happy with even 100hz scanning rate. This is the first design cycle of this thing I'm building so I plan to get it working to some degree and then start refining it.

[calvingloster]

If the piezo element is divided into 4 quadrants is it safe to assume the capacitance is 1/4 per quadrant?