LM96550

Hello Yuan,

Welcome to TI E2E forum.

I am moving your post to the correct forum that handles LM96550.

Hi Yuan,

How do you power up the +50V(VPP) and +40V(VPF)? Do you power up the 50V first and then the 40V? You would damaged the device. From page 13 of the user guide,

Regards,

Charles

Hi Yuan,

Sorry, the image from page 13 of the user guide didn't paste properly. I'm just going to re-write it. "Caution: To prevent fatal device damage, VPF>=VPP-14V and VNF<=VNN+14V at ALL TIMES, including during power on and power off."

Regards,
Charles

I power up the 50V and 40V at the same time. And it still burned up. Thank you very much for your help.

Do you mean that I should power up the power supply +/-10 v first and then the +/- 50v, so that the +/- 40v and +/-50v can be powered up at exactly at the same time ? For I just at first manually power up the +/- 40v and +/- 50v .

You can use the configuration in figure 5 of the user guide (page 12) to power up and down the TX_SDK_V2 board.

Yes, when I testing the board, I use the configuration in the figure five to power up and follow the power up sequence in next page too, but the burned up problem there....

So when did you power up the +/-10V? When powering up, did you follow the sequence in figure 5 highlight in purple circles? When powering down, follow the sequence shown in blue circles.

Hi, I meet a problem about LM96550 and LM96551:

Can I replace LM96550 with LM96551 directly? I look at their datasheet, these two and pin to pin compatible. But I notice that LM96551 don't need +/-40 power supply. For LM96550, the pin 8,53 is supposed to connected to +40 power supply and pin 10,51 are connected to -40 power supply. So in LM96551, what should I connected for these four pin.
Looking forward to your reply. Thank you very much for your help and best wishes.

Sincerely,
Yuan

Hi Yuan,

Yes, you can replace the LM96550 with the LM96551. In the LM96551, you should connect put 10uF || 0.1uF bypass caps between VPP (pins 4-7 & 54-57) and VPF (pins 8 & 53). Similarly, put 10uF || 0.1uF bypass caps between VNN (pins 11-14 & pins 47-50) and VNF (pins 10 & 51).

Regards,

Charles

Hi:

I have design a PCB for the LM96570 and LM96550 for PZT (Piezoelectric) driver. I have already make that board work which the eight channels of LM96550 can output  50v square pulses and everything seems works find with delay and frequency. the first picture is the one channel of output signal from the LM96550 before I connected to PZT. However, after I connected the output to one PZT-5H about 5s, the chip LM96550 started to burnt with fire suddenly. I am not sure what cause this burnt problem. The Picture to is my PCB schematic and Layout. Could you please give me some help about this problem?

Hi Yuan,

I assume you following the same power up sequence whether the PZT is connected or not.

The 330pF cap from the LM96550 output to ground emulated the PZT's capacitance. If you connect to the PZT, remove the 330pF caps.

Regards,

Charles

Thank you very much for your reply. I will try remove the 330pF caps. When I following the power up sequence, the PZT is not connected. I connected the PZT after the power up. Should I connect the PZT during the power up sequence or not?

Hi Yuan,
It shouldn't matter. However, to be on the safe side, I would connect the PZT before power up.
Regards,Charles

Dear Yuan!

Where could you find the LM96550, 96570, 96530, etc. schematic models for Eagle (or Orcad Pspice)?

I tried to find them for designing and for simulation, but i could not find.

Thanks,

Endre

Dear Yuan!

Where could you find the LM96550, 96570, 96530, etc. schematic models for Eagle (or Orcad Pspice)?

I tried to find them for designing and simulation, but i could not find.

Please help me.

Thanks,

Endre