TL3474 - diode clamp

Hirotaka Matsumoto

Other Parts Discussed in Thread: TL3474

Hi all,

Would you mind if we ask TL3474?

We have the same question as the following.
https://e2e.ti.com/support/amplifiers/precision_amplifiers/f/14/p/409755/1455095
We'd like to confirm one point.
Inputs of this device have diode clamps also, right?

Kind regards,

Hirotaka Matsumoto

over 9 years ago

0 Ron Michallick over 9 years ago

TI__Guru*** 149666 points

Hirotaka-san,

TL3474 input pins do not have diodes to VCC+ supply.
TL3474 input pins do have diodes to VCC-/GND supply.

0 Hirotaka Matsumoto over 9 years ago in reply to Ron Michallick

Guru 27585 points

Ron san

Thank you for your reply.
OK, we got that it is required external diode for voltage clamp.

Kind regards,

Hirotaka Matsumoto

0 Ron Michallick over 9 years ago in reply to Hirotaka Matsumoto

TI__Guru*** 149666 points

Hirotaka-san,

The inputs block current flow when VCC = 0V and input(s) are > 0V.
Therefore the external diodes should not be needed.

0 Hirotaka Matsumoto over 9 years ago in reply to Ron Michallick

Guru 27585 points

Ron san

Thank you for your prompt reply.
Ok, we misunderstood what "do have" means.

Kind regards,

Hirotaka Matsumoto

0 Ron Michallick over 9 years ago in reply to Hirotaka Matsumoto

TI__Guru*** 149666 points

Hirotaka-san,

If input goes below ground (VCC- pin), a diode will conduct current from input pin.
If input goes above VCC+ pin, no current will flow.

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TL3474 - diode clamp