Other Parts Discussed in Thread: SN74LVC1G14
Tool/software:
Hi,
We are currently evaluating the use of a Schmitt-trigger inverter for one of our customers, and SN74AHC1G14 has been shortlisted as a candidate device.
However, the following usage condition is expected:
Condition:
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The VCC pin is not powered (0V) while a voltage of approximately 3.3V is applied to the A input pin
According to the SN74AHC1G14 datasheet, the input is described as overvoltage tolerant "up to 5.5V at any valid VCC."
We interpret this statement to mean that the input is tolerant only when VCC is within the recommended range (2V to 5.5V), and that operation at VCC = 0V is not guaranteed.
Additionally, since SN74AHC1G14 does not support Ioff or Partial-Power-Down, we understand that applying input voltage when VCC is 0V could lead to reverse current through internal diodes and possibly cause latch-up or damage.
Based on this, we consider that SN74LVC1G14, which supports Ioff and Partial-Power-Down, would be a more suitable solution for the customer’s requirements.
Could you kindly confirm the following:
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Is it correct that applying an input voltage (e.g. 3.3V) to SN74AHC1G14 while VCC = 0V may result in reverse current and potential reliability issues?
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Given the condition above, is recommending SN74LVC1G14 (with Ioff) a proper and safe alternative?
Best regards,
Conor
