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# LM224: Maximum Voltage Rating for Input Voltage

Part Number: LM224

Hi Team,

Customer wants to know whether below maximum rating for input voltage(VI) is related to supply voltage (single rail or dual rail)?

In our datasheet, the maximum rating of VI is -0.3 to 32V. Does this apply for all conditions? If not, how this value is estimated with supply voltage? You can check below screenshot for reference.

Best Regards,

Stanley

• If the specification does not mention VCC, then it is independent from VCC.

Because the inputs have no internal diodes to VCC, the input voltage can exceed the VCC voltage. If this occurs, the input will block current flow due to a reverse biased diode forming in the input PNP transistor. Current flow is blocked even if VCC equals 0 V.

• Hi Clemens,

But from customer's feedbacks, they power our LM224 by ±15V and find out our device can work fine when input voltage is lower than -2.5V. So I guess the maximum rating of input voltage should be related with supply voltage. Right?

If not, can you further explain this? Thanks.

Best Regards,

Stanley Dai

• Footnote (2) says:

All voltage values are with respect to the network GND.

When you have ±15 V supplies, then the voltage at the LM224's GND pin is what you call −15 V. For the LM224, the supplies are 0 V and 30 V.

So what you call −2.5 V, is 12.5 V from the point of view of the LM224. This is inside the absolute maximum ratings.

• Stanley,

Input voltage is always relative to pin 11 (LM224 GND pin)