TVS3300: Series connection

Michael Lawton

Part Number: TVS3300
Other Parts Discussed in Thread: LMR36506, , TVS2700, INA229, ATL431LI

I have an application where I have a working voltage of 3V to 60V (up to 65V preferred) and a max clamping voltage of 70V. It will be used to protect the input of an LMR36506 and an INA229. Is it possible to use a TVS3300 and TVS2700 in series? Or can you suggest another solution with low cost, quiescent current and small footprint that uses an external mosfet? Any circuitry would need to be powered by the rail so it can protect from a sudden transient when otherwise unpowered.

over 4 years ago

0 Matt Smith over 4 years ago

TI__Genius 9806 points

Hello Michael,

In theory this could work, but we cannot guarantee a linear increase in Vrwm since we do not test for this. Please refer to this similar E2E thread for more details: https://e2e.ti.com/support/interface-group/interface---internal/f/interface---internal-forum/1004400/tvs3300-tvs-diodes-in-series?tisearch=e2e-sitesearch&keymatch=TVS3300%20in%20series#

Regards,

Matt Smith

0 Michael Lawton over 4 years ago in reply to Matt Smith

Prodigy 50 points

Hi Matt, that link doesn't seem to work for me.

+1 Matt Smith over 4 years ago in reply to Michael Lawton

TI__Genius 9806 points

Hi Michael,

My mistake. I didn't realize that was from an internal forum. Basically, the main thing you need to be aware of is that clamping voltage will be much higher with 2 TVS diodes in series. This is because there will be a higher resistance path to ground than with just one. A surge test will need to be run on this combination to make sure that Vclamp does not exceed your systems transient abs max.

Regards,

Matt Smith

0 Michael Lawton over 4 years ago in reply to Matt Smith

Prodigy 50 points

I am looking into other options for flat-clamp TVS as the combined clamping voltage of a TVS3300 and TVS2700 is already marginal.

I'm thinking of using a TVS diode in parallel with a mosfet like the Diodes Incorporated DMT6017LFDF which is rated at 65V and has a very low RDS(ON). I would control the mosfet with an external comparator.

Do you think your ATL431LI would be fast enough to be effective for an 8/20uS surge running as an open-loop comparator? Or another option I've seen might be to use a long tailed pair as a comparator with the ATL431LI simply acting as a voltage reference.

I want to limit the current taken from the HV rail to only a few 10s of uA max so preferably the comparator or reference would run from my DC-DC 3.3V rail. Maybe the boot pin of the LMR36506 (3.3V + 3.15V) could be used to drive the mosfet gate.

0 Abhishek Wadhwa over 4 years ago in reply to Michael Lawton

TI__Intellectual 1135 points

Hi Michael,

The pulse response of ATL431LI can be found in the datasheet. Below is the pulse response. Please keep in mind that ATL431LI has an abs max of 18mA Cathode current.

0 Abhishek Wadhwa over 4 years ago in reply to Abhishek Wadhwa

TI__Intellectual 1135 points

Hi Michael,

Did my response answer your question? Please let me know if you have any follow-up questions

Best,

Abhishek

Interface

Interface forum

TVS3300: Series connection