SN74LVC1G07: VIH, and VIL

Brian Wang0928

Genius 14300 points

Part Number: SN74LVC1G07
Other Parts Discussed in Thread: SN74AHCT1G125, SN74LV1T34

Hello,

There is a question abut the input voltage level.

If input voltage level works at between 0.3xVCC to 0.7xVCC, how is the behavior of the output? thanks.

Regards

Brian

over 3 years ago

+1 Clemens Ladisch over 3 years ago

Guru 318050 points

The output can be low, or off, or it can oscillate. The device might be damaged. See [FAQ] How does a slow or floating input affect a CMOS device?

0 Brian Wang0928 over 3 years ago in reply to Clemens Ladisch

TI__Genius 14300 points

Thanks.

Is there similar part that the VIH is lower like as 0.5xVcc,min? Or it's CMOS level fixed with 0.7xVCC,min and 0.3XVCC,max? thanks.

Regards

Brian

0 Clemens Ladisch over 3 years ago in reply to Brian Wang0928

Guru 318050 points

All LVC inputs have symmetrical thresholds.

With a 5 V supply, devices with TTL-compatible inputs have lower thresholds (V_IH = 2 V). And there are voltage-translating gates. However, there is no such device with an open-drain output.

You have to combine a low-threshold device like the SN74AHCT1G125 or SN74LV1T34 with an open-drain buffer.

0 Emrys Maier over 3 years ago in reply to Brian Wang0928

TI__Guru* 97066 points

Hey Brian,

If your output is 5V and the input is larger than 2V, then you can use the SN74AHCT1G125 directly. Just connect A to GND and put your input signal on OE\, and the output will be low when OE\ = low, and hi-z when OE\ = high.

Logic

Logic forum

SN74LVC1G07: VIH, and VIL