TCA9517A: Can VCCA higher than VCCB

Part Number: TCA9517A
Other Parts Discussed in Thread: TCA9517-Q1

Hi Team

Could you help advice can I use TCA9517A with VCCA=5V and VCCB =3.3V? because sideB VOL is higher than isolator VIL, so I have to connect TCA9517A side A to isolator.

And can Enable pin connect to 3.3V directly?

Thanks for support!

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 317390 points

The TCA9517-Q1 allows V_CCA > V_CCB.

0 AD over 1 year ago in reply to Clemens Ladisch

Intellectual 300 points

Thanks Clemens, as I already have some samples of TCA9517ADGKR, I would like to test it on protype.

If TCA9517A not allows V_CCA > V_CCB. doest it allows V_{CCA =} V_CCB=3.3V

+1 Clemens Ladisch over 1 year ago in reply to AD

Guru 317390 points

Yes; the same voltages are OK.

+1 Tyler Townsend over 1 year ago in reply to AD

TI__Mastermind 48338 points

Hi Allen,

I believe using TCA9517A with VCCA > VCCB will still work. There might be a couple things to keep in mind when having this type of configuration. VCCA = VCCB is ok.

The device will still operate properly with being able to transmit a low from A-side to B-side and B-side to A-side no problem.

The prop delays and VIL on A-side may not meet our datasheet electrical specs any more.

If you are okay with not being able to meet the electrical specifications in the datasheet but are able to use the device from a functional standpoint, then TCA9517A would be okay to use in your application regardless of VCCA being the low-side voltage.

Here is the thread I was referencing asking the same question:

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/774482/tca9517a-about-vcca-vccb?tisearch=e2e-sitesearch&keymatch=tca9517a%20vcca#

Again, same voltages work out, VCCA=VCCB is okay.

Regards,

Tyler

0 AD over 1 year ago in reply to Tyler Townsend

Intellectual 300 points

Hi Tyler,

Thanks for the information, slight lower VIL A-side should still ok for us, I will test it.

And will change the dsign to TCA9517-Q1 later on.

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TCA9517A: Can VCCA higher than VCCB