TPS659037: External Oscillator

Richard Elmquist

Part Number: TPS659037

The TPS659037 requires an external oscillator to operate. I have read in several E2E posts that it must have a crystal oscillator (sine wave). My customer is asking the following question:

This is the oscillator that I want to use with the TPS659037:

SG-210STF

http://www5.epsondevice.com/en/products/spxo_standard/sg210stf.html

This is CMOS output oscillator. I'm trying to understand if we can use crystal oscillator (Crystal unit + oscillation circuit) instead of just the crystal unit.

Can you verify if this oscillator would work and if so send a diagram of how the customer should configure it to work properly with the TPS659037? I do not believe that it will work from the comments in the forum, but I need you to verify this for the customer.

Thanks for your help with this!

Richard Elmquist

over 7 years ago

0 Krishnamurthy Hegde over 7 years ago

TI__Expert 8730 points

Hi,

I have assigned your request to responsible Applications Engineer and we will get back to you as soon as possible.

Regards,

Murthy

0 Karl Wallinger over 7 years ago in reply to Krishnamurthy Hegde

TI__Genius 16030 points

Richard,

It's a bit hard to tell from the datasheet alone. The TPS659037 device has an internal oscillator, so in general we use an external crystal instead of an external crystal oscillator. So I can't say for certain that it would work.

You could try to contact the manufacturer and see what the output is of the crystal oscillator you show.

Regards,
Karl

0 Richard Elmquist over 7 years ago in reply to Karl Wallinger

TI__Mastermind 45250 points

Karl,

I will try and get the information from the customer. I will post it as soon as I receive it.

Thanks for your help with this!

Richard Elmquist

0 Richard Elmquist over 7 years ago in reply to Richard Elmquist

TI__Mastermind 45250 points

Karl,

The customer has stated that the output of the SG-210STF is a square wave. My understanding was that the input needed to be sinusoidal. Can you comment on this? Will the oscillator work? If so can you explain the connections that he needs to use?

Thanks for your help with this!

Richard Elmquist

0 Karl Wallinger over 7 years ago in reply to Richard Elmquist

TI__Genius 16030 points

Richard,

That was my guess as well, but good to get confirmation. A square wave will not work, since the oscillator has DC blocking caps in series at the input, since it was designed to support a crystal and the oscillator is in the PMIC. It must be a sine wave to work properly.

So your customer should use an external crystal, sometimes called "crystal units" by manufacturers. This will work with the oscillator in the PMIC.

Regards,
Karl

0 Richard Elmquist over 7 years ago in reply to Karl Wallinger

TI__Mastermind 45250 points

Karl,

I appreciate your fast response!

Have a great weekend.

Richard Elmquist

Power management

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TPS659037: External Oscillator