TCAN1051HV-Q1: ESD Related

REDDY Y

Part Number: TCAN1051HV-Q1
Other Parts Discussed in Thread: ISO1042-Q1, , TCAN1051HV, STRIKE

Hi TI Team,

We have two PCB variants of the same design in which we use the TCAN1051HV-Q1 (Non Isolated) & ISO1042-Q1 (Isolated) parts (schematic as shown below).

These two variants have the same design/circuit, but the PCB size, part placement and routing is different (layout is different) to accommodate PCB size for different enclosure needs.

In variant 1 (old) PCB design, both Iso & Non-ISO ICs CANH, CANL pin ESD levels are PASS up to 15kV contact discharge.

In variant 2 (new) PCB design, both Iso & Non-ISO ICs CANH, CANL pin ESD levels are only 6kV contact discharge Pass.

From 8kV to 15kV contact discharge, irrespective of where we apply (ISO or Non-ISO CAN lines) Non-ISO CAN IC (TCAN1051HV) is latching and heating up. After power-on reset of the entire board, the IC started working.

We tried various layout options but were unable to improve the ESD Pass level from 6kV to 8kV also. Our required ESD level is 15kV. We need your support in understanding this and resolving it to improve the design.

We will share the Gerber & Full sch through DM/over email.

Thank you.

9 months ago

0 Sean Guo 9 months ago

TI__Mastermind 19050 points

Hi Reddy,

Could you provide more information about your test method? Was it powered or unpowered device? TCAN1051HV is rated for ISO10605 powered contact discharge of 8 kV, unpowered ESD performance is often improved as none of the driving circuitry is active.

TVS diodes should be placed as close as possible to the ESD entry points. So make sure to place it near the connector. Termination resistors should not be the first component exposed to ESD strike.

Regards,

Sean

0 REDDY Y 9 months ago in reply to Sean Guo

Intellectual 870 points

Hi Sean Guo,

Thanks for the response. Tested while the DUT is in Power ON condition and IC is Latching up after ESD contact discharge. In our layout its not very close to the connector but we have tried that also by manually soldering additional TVS directly on the connector pin. There was NO improvement (6kV PASS, 8kV Fail).

0 Sean Guo 9 months ago in reply to REDDY Y

TI__Mastermind 19050 points

Hi Reddy,

Can you provide the ± 8kV Clamped IEC Waveform based on IEC 61000-4-2 ratings?

Regards,

Sean

0 REDDY Y 9 months ago in reply to Sean Guo

Intellectual 870 points

Hi Sean

We couldn't capture any waveforms due to the lack of an HV Logging instrument. Could you assist us in reviewing the PCB layout and provide feedback if there are any major issues contributing to this problem?
Asking beacuse, As I mentioned, we have two PCB variants of the same design. The first variant handles 15kV, whereas the second variant, with the same circuit and components, but different layout only handles 6kV.

0 Sean Guo 9 months ago in reply to REDDY Y

TI__Mastermind 19050 points

Hi Reddy,

Yes sure please share the schematic and layout of both new and old boards. It's a pretty large difference for just a layout change, so I hope we see something blatant.

Regards,

Sean

0 REDDY Y 9 months ago in reply to Sean Guo

Intellectual 870 points

Hi Sean
Shared design files through Private Message.

0 Sean Guo 9 months ago in reply to REDDY Y

TI__Mastermind 19050 points

Hi Reddy,

We are reviewing your schematics and layouts. Tomorrow is a US holiday so we'll get back to you by early next week.

Regards,

Sean

0 REDDY Y 9 months ago in reply to Sean Guo

Intellectual 870 points

Hi Sean
Waiting for your kind feedback

0 Sean Guo 9 months ago in reply to REDDY Y

TI__Mastermind 19050 points

Hi Reddy,

Sorry for the delay, we are still reviewing your layout. it may be tricky to find out what exactly is going on. I'll let you know what we find out with the layout differences by next week.

Regards,

Sean

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TCAN1051HV-Q1: ESD Related