THS3491RGTEVM: 15V square wave from 3V3

Why did you choose the THS3491? To get a square wave, you could use a comparator, or, if you need high drive strength, a gate driver like the UCC27517 (15 V) or UCC27537 (30 V).

Hello Ahbib,

Can you clarify what results you are seeing from your board? Can you share TINA simulations?

Best,

Hasan Babiker

Hello Hasan,

Tina circuit and simulation in below and I receive this wave around. No problem with that. But now I have heating problem with opamp. There is no output load but it is heating, 30mA around both supply (-5V,+20V). Do you have any suggestion?

Hello Clemens, Thank for advice. We want different output voltage with same circuit with different variant. so opamp were proper for project. But I will consider your advice. Thanks again. 

Ahmet

Hi Ahbib,

try this circuit:

ahbib_ths3491.TSC

Kai

Hello Ahbib,

Are you referring to 30mA supply draw in simulation or are you measuring this on your board?

Best,

Hasan Babiker

Hello Hasan,

I measure it on board. 

Sincerely yours

Hello Kai,

I tried and changed R7 and R4 but still heating.

Thanks

Hi Ahbib,

have you added R1 and measured behind R1 (not directly at the output)?

Kai

Hi Ahbib,

does it work now?

Kai

Hello Kai,

opamp is working both way but opamp is still heating. 

Hello Ahbib,

Did you add a series resistor to the output? What is the impedance of the scope you are measuring output with, is it a 50-ohm load?

Best,

Hasan Babiker

Hi Ahbib,

please show your latest schematic. And please post a photo which shows your modifications carried out on the EVM board.

Maybe you have damaged the OPAmp during experimenting? Then check again with a fresh one :-)

Kai