The datasheet specifies the input voltage range as –0.3V to 32V. Other vendors mention that an additional criterion is that Vcc must not be exceeded. Is it true that the TI LM324 will survive up to 32V even while it is unpowered (no voltage at supply pins)?
What about the output? The datasheet mentions that a short to Vcc can destroy the chip. Will it survive 10V-12V at the output while unpowered?
Hi Martin,
Welcome to E2E!
Please refer to the Application Design Guidelines for the LM324: https://www.ti.com/lit/pdf/sloa277
For the inputs, the LM324 can be applied up to 32V (abs max) with respect to network GND.
On the output side, could you clarify what the output is connected to and how the 10-12V would be applied?
Regards,
Ashley
Perfect, thanks a lot! This clears up my question about the input.
Regarding the output, I'm attaching an image of the circuit in question. Vsupply may be 12V, or not present (0V). The circuit is a buffer while the op-amp is powered, otherwise the LED and load will only be driven by the unbuffered Vinput signal, the impedance of which is unknown (external device).
Hi Martin,
Thank you for sharing the schematic. It is not recommended to pull the output to a voltage beyond the supply voltage as this could damage the part due to high output current. The part could overheat during this operation.
Section 3.4 (Short Circuit Sourcing Current) and Section 3.5 (Output Voltage Limitations) from the Apps Note I sent early explain this.
Regards,
Ashley
