SN74LVC3G04: oscillator circuit

K.Hamamoto

Part Number: SN74LVC3G04
Other Parts Discussed in Thread: SN74LVC3GU04, SN74LVC1GX04

The our customer is going to use this device for oscillator circuit with crystal.

On the following document, the unbuffered inverter is recommended. Because the buffered inverter has high gain and is less stable.

http://www.tij.co.jp/jp/lit/an/szza043/szza043.pdf

Is this device the unbufferd type? or buffered type?

If it is the unbuffered type, can this device use with 150MHz?

Could you let me know if you have any other recommended device? (We need multi channel type. >3ch)

Regards,

Koji Hamamoto

over 7 years ago

0 Clemens Ladisch over 7 years ago

Guru 317000 points

Unbuffered devices are marked with a "U" in their name.

You can get three unbuffered inverters in the SN74LVC3GU04. (The datasheet quotes a maximum t_pd of 3.9 ns at 3.3 V.)
However, it might be a better idea to use the SN74LVC1GX04. Its datasheet says this about the open loop gain:

What is the exact circuit to be used?

0 K.Hamamoto over 7 years ago in reply to Clemens Ladisch

Guru 12155 points

Hi

Thank you for your reply.

I do not get the exact circuit. However they says that the feedback resistor is 1Mohm and the capacitor is 7pF.
Which can we use SN74LVC3GU04 or SN74LVC1GX04 for 150MHz oscillator circuit with crystal?

Regards,
Koji Hamamoto

0 Clemens Ladisch over 7 years ago in reply to K.Hamamoto

Guru 317000 points

Both devices can switch at 150 MHz (if VCC isn't too low).

But for 150 MHz, you need an overtone crystal, for which the standard circuit is unlikely to work.

0 K.Hamamoto over 7 years ago in reply to Clemens Ladisch

Guru 12155 points

Hi Clemens,

Thank you!

Logic

Logic forum

SN74LVC3G04: oscillator circuit