CD74HCT297: Need NE568A repalecement

Mickey Zhang

Genius 12080 points

Part Number: CD74HCT297
Other Parts Discussed in Thread: LMX2582, SN74LV4046A, CD74HC7046A, CD74HCT7046A, CD74HC4046A, CD74HC297

Hi team,

The customer needs to replace NE568A. The NE568A datasheet is in the attach.

He needs the PLL frequency of the replacement is above 40MHZ and the replacement should have FM demodulators function.

Would you recommend a suitable device? How do you think CD74HCT297?

Best Wishes,
Mickey Zhang
Asia Customer Support Center
Texas Instruments

NE568A.pdf

over 6 years ago

0 Emrys Maier over 6 years ago

TI__Guru* 96591 points

Hi Mickey,
It would appear that the NE568A is an analog PLL. All of the PLL's in the Standard Logic portfolio are digital PLL -- ie they work on and generate square waves. We don't have a direct replacement.

I guess it's possible to replace an analog FM demodulator with a digital PLL, but I would also guess that it would add a significant amount of phase noise and hurt the quality of the final signal significantly. You might check with the PLL team inside TI (the same group that handles the LMX2582).

We have several PLL's in the logic portfolio if they want to try to use them:
SN74LV4046A
CD74HC7046A
CD74HCT7046A
CD74HC4046A
CD74HC297
CD74HCT297 (the one you listed above)

0 Mickey Zhang over 6 years ago in reply to Emrys Maier

TI__Genius 12080 points

Hi Emrys,

OK. Thanks for your suggestions.

Logic

Logic forum

CD74HCT297: Need NE568A repalecement