OPA691: opa691

Naveenkumar K

Part Number: OPA691
Other Parts Discussed in Thread: TINA-TI

hi am naveen am design a bandpass filter using opa691 in that i want single supply only can you share the single supply design file with filter circut

over 6 years ago

0 kai klaas69 over 6 years ago

Guru 140200 points

Hi Naveenkumar,

can you show a schematic of your planned circuit?

Kai

0 Hasan Babiker31 over 6 years ago

TI__Genius 15565 points

Hello Naveen,

Which file are you referring to?

Best,
Hasan Babiker

0 Naveenkumar K over 6 years ago in reply to kai klaas69

Prodigy 80 points

yes sure how can i share the schematic

0 Naveenkumar K over 6 years ago in reply to kai klaas69

Prodigy 80 points

BPF -design 100K(opa691).pdf BPF -design 100K(opa691).pdf

0 Naveenkumar K over 6 years ago in reply to Naveenkumar K

Prodigy 80 points

i already done circuit rig up with this circuit but it was not working i want 100khz fc band pass filter pass band -3db down range .stop band -40db band width app*3khz

0 Naveenkumar K over 6 years ago in reply to Hasan Babiker31

Prodigy 80 points

i designed circuit with ti filter design tool pfa file but it was not working can u help me for design a new circuit

0 kai klaas69 over 6 years ago in reply to Naveenkumar K

Guru 140200 points

Hi Naveenkumar,

the shown circuits cannot run with a single supply voltage. You must introduce a midsupply bias voltage as shown in figure 2 of datasheet.

Kai

0 kai klaas69 over 6 years ago in reply to kai klaas69

Guru 140200 points

Hi Naveenkumar,

when running a TINA-TI simulation I get different results:

naveenkumar.TSC

Also, as the OPA691 shows huge input bias currents, the resistances R4 and R9 are much too high. This results in an output offset voltage of more than 600mV.

Kai