OPA171: OPA171AIDBVR internal clamp diode from VIN+/- to VDD

Red Yen

Expert 4360 points

Part Number: OPA171
Other Parts Discussed in Thread: TLV171, , OPA348

Dear support team

may i have your help to check if OPA171AIDBVR has internal clamp diode from IN+/- to VDD as following red circle

since my customer facing the issues because of this diode, do we have similar part WITHOUT this clamp diode?

thanks a lot

over 6 years ago

0 Tim Claycomb over 6 years ago

TI__Genius 15410 points

Hi Red,

Yes the TLV171 does have a diode from IN+ to VDD. Almost all amplifiers have this diode to VDD.

What issue is your customer seeing with the diode? The only way the diode can cause issues is if the input exceeds the supply voltage by at least ~0.5V.

Thank you,

Tim Claycomb

0 Ron Michallick over 6 years ago in reply to Tim Claycomb

TI__Guru**** 159501 points

Red,

TS321IDBVR does not have a diode from inputs to VDD. However, this device is slower and not rail to rail input or output.

0 Red Yen over 6 years ago in reply to Ron Michallick

TI__Expert 4360 points

Ron,

since TS321IDBVR spec would not compete with OPA171,

may I know if we have similar performance and no internal clamp diode from VIN +/- to VDD part?

thanks a lot

0 Ron Michallick over 6 years ago in reply to Red Yen

TI__Guru**** 159501 points

Red,

Try OPA348, this is only "modern" op amp that I found with no input to V+ diode.
There may be others , but no easy way to find them.

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OPA171: OPA171AIDBVR internal clamp diode from VIN+/- to VDD