OPA2206:Amplifiers forum

Kenta Matsuura

Prodigy 10 points

Part Number: OPA2206

Tool/software:

過電圧保護について知りたいです。

絶対最大定格信号入力ピン電圧は (V+) + 40 と記載されていますが、電源オフ (V+=0) の状態で入力ピンに 12V 信号が印加された場合、この IC は保護されますか?

5 months ago

+1 Clemens Ladisch 5 months ago

Guru 280950 points

This makes no difference; the protection circuit does not need a regular power supply.

But note that overvoltage causes a current to flow into the power supply (see section 7.3.1).

+1 Raymond Zhang1 5 months ago

TI__Guru 56251 points

Hi Matsuura-san,

This figure is what Clemens refers to. I interpret the query based on the translation.

Yes, IC's input terminal will be protected even under the non-powered LDO or V+ state, however, the protection circuit must provide ZD1 for the current path, since most LDOs on the market is unable to sink current.

If V+ is able to sink current, then ZD1 is not required per the query (single supply rail case, where V- = GND).

The same is true for the IC's negative input terminal under-voltage protection as well, assume dual supply rails.

If you have other questions, please let us know.

Best,

Raymond