TPD2S017 OPERATING VOLTAGE

Hi Jim,

This is an older part that, while a decent performer, has a somewhat "details-lacking" data sheet. The maximum voltage for VCC is not even specified! Sorry about that. I am fairly certain the VIO absolute-max voltage is going to be the maximum voltage that can be applied to the device before it exceeds the diodes reverse standoff voltage, also called "working" voltage, VRWM. After that current begins to flow and may attenuate the signal. The VBR is specified as 11-V Min, 12-V typical. This applies to the VIO pins. So it is not clear to me how we can spec 5-V ABS(Max) and then spec it 12-V Typical Vbr.

The VCC pin can be used to add bias against the VIO pins, thus increasing Vbr (of the VIO pins) by Vcc minus the V_Zener (VZ ~= 5V). You should be able to add at least 5.5-V to Vcc without problems. My apologies for the state of this data sheet, it leaves a lot more unanswered than answered it seems!

If you are looking at this device because of the integrated RC filter than I would be happy to help you out and try and get some more information on the device parameters.

If you are looking for ESD protection we have a great many newer parts, which have been properly described in their respective data sheet.

Please have a look at: TPD2E001, TPD4E001, TPD2E2U06, TPD4E05U06, TPD2EUSB30A, TPD4E1U06, etc.

If you let me know your data rate and Vswing_Min and Max I will be able to suggest a good device.

Regards,

Hey thanks for the quick response!  I went over all the parts you listed.  I like the part with the higher rating TPD2E2U06 but it does not have a vcc pin.  I am not an expert on this but it seems to me that it would be better to clamp the i/o at vcc + 1 diode drop as that zener clamping at 9.7V seems a little high to me although a good thing.  So something like the TPD2E2U06 with a vcc pin would seem like a solution and maybe a dual or quad.  I would also like the sot23-5 or -6 if possible. 

We are trying to protect uP SPI lines and Limit sensor lines etc in our machine that travel through long wire harnesses to the board.  They are not very high speed. About 1M baud.  The SPI lines are 3.3V and the sensor lines are 5V open collector.  Once this problem is solved then I will start worrying about ringing and noise.  That is why I liked the embedded resistor.

Thanks but why would having a vcc pin increase the clamping voltage?  Isn't the internal zener going to clamp at the same voltage as it would anyway? Plus I will have capacitance on the vcc pin that the transient will see first at only 1 diode drop above vcc.  It will have to charge that up before it can pull vcc up.  Then the internal clamp would start to draw current. 

Hi Jim,

Actually, the disadvantage of the Vcc pin is more accurately described as the required bypass cap increasing the part count. Having a Vcc pin will decrease the clamping voltage, for that part. It is my understanding that creating a part which does not need the Vcc pin meant we needed to lower the Rdyn of the Zener, which would lower the clamping voltage for the device without the need for Vcc. So that's what I meant, typically we get a lower clamping voltage when comparing devices that need Vcc versus those that don't.

Our lowest clamping device in SOT-23 is the TPD4E001 in DRL package. It has about half of the clamping voltage as the TPD4E1U06, but it needs Vcc and a bypass cap. It is an older device, but is still one of our best sellers due to its low clamping voltages. I would pick this device due to it's low clamping voltage. 

Regards,

Hi Guy,

I am curious if you tried to say that the  TPD4E001 has a lower breaking voltage. According to specification,  the TPDSE1U06 has a lower V clamp at 3A than TPD4E001 would have at 5A. I am not sure if  there is a linear  relationship between the Vclamp and current.

Alex

Thank you,

i see now. Can you provide Rdyn for the TPDE4001? Looks like this parameter is missing from the specification

Alex