Hi Hooman, Thank you so much for your response! Output impedance of LM96550 : it is definitely very good to know that LM96550 should be able to handle the low loads on the order of 50 Ohms. The datasheet for LM96550 does not mention the output impedance of 5 Ohms. It does mention however the value of "Output ON Resistance" to be 7...11 Ohms. Is this the output impedance the LM96550 designer is referring to? Malfunction of LM96550 . I am actually not sure anymore if we even will get a chance to test out the performance of LM96550 with our transducers. The chip burned out before we made any changes to the board and before connecting the external transducers. It was the first time we tried to power up the board and I think we followed the power up sequence in the right order. We went through the following steps: We connected the FPGA to PC and the TX board. The SAMTEC connector was also plugged to the TX board, but nothing was connected to the SMA connectors. The ground lead (the black banana cable) was connected to the ground of one of the power supplies -50 V was powered up. We do not have an extra power supply for VSUB, hence J_SUB header was configured in 1-2 position to link -50 V and VSUB together. Thus, VSUB banana plug was left unconnected As soon as -50 V was powered up, the LM96550 sparked up. On a figure below you can see a black mark left in the area where the chip was sparking. I would be very grateful if you could help us to resolve this issue as quickly as possible. It took us a while to put the setup with all the power supplies together, and in the end, we did not get a chance to evaluate the performance of any of the chips even once. Thank you! Dmitrijs
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