LM224: Maximum Voltage Rating for Input Voltage

Stanley Dai

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

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 247900 points

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

Design Guidelines for Devices with LM324/LM358 Cores says:

Because the inputs have no internal diodes to V_CC, the input voltage can exceed the V_CC 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 V_CC equals 0 V.

0 Stanley Dai over 3 years ago in reply to Clemens Ladisch

TI__Expert 5810 points

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

0 Clemens Ladisch over 3 years ago in reply to Stanley Dai

Guru 247900 points

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.

0 Ron Michallick over 3 years ago in reply to Stanley Dai

TI__Guru*** 141006 points

Stanley,

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

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LM224: Maximum Voltage Rating for Input Voltage