Tool/software:
こんにちは。SN74ALS245A-1NSRを使用して製品を設計しています。1. A0-A7、B0-B7pinの最大定格の下限はどれくらいですか?2.現在、パルス入力の立ち下がりエッジは5nsで-0.5Vを超え、-0.96Vです。これは使用しても大丈夫ですか?どんな助けでもいただければ幸いです。ありがとうございます。
The datasheet does not specify a limit for the negative input voltage, or for the input current. It only specifies VIK, but that value is not helpful.
You have to ensure that the power dissipation in the clamping diode does not become high enough to damage the device. Estimating roughly 1 V × 50 mA = 50 mW, this would result in a temperature increase of 60 °C/W × 50 mW = 3 °C over ambient for a DC current. So it's probably safe.
To avoid the undershoots, properly terminate the trace.
Is there a reason why you are designing a new product with such an old, bipolar device? It might indeed be more robust than newer CMOS devices, but in general, the much lower power consumption and higher speed of CMOS devices makes them preferrable.
