THVD1505: need a ref design of THVD1505

Yue TANG

Part Number: THVD1505

Hi,

I can't find any ref design for THVD1505. Customer need this device to support 18KV air-gap discharge. please kindly suggest a ref design to meet this requirement . thanks.

over 3 years ago

0 Max Robertson over 3 years ago

TI__Guru 62910 points

Hi Yue,

You could reference Figure 28 in the datasheet for an example implementation showing additional protection circuitry. For 18 kV IEC 61000-4-2 air gap discharge the circuit on the left could be used, and the series resistances could be considered optional as long as the TVS clamping voltage is low enough. For TVS selection, you could reference this blog for further details:

https://e2e.ti.com/blogs_/b/industrial_strength/archive/2017/11/13/how-to-choose-a-tvs-diode-for-rs-232-rs-485-and-can-based-on-voltage-ratings

Please let us know if you have any further questions.

Regards,
Max

0 Yue TANG over 3 years ago in reply to Max Robertson

TI__Expert 8485 points

Max,

Is there any specific attentation need in your suggested schematic to support auto polarity ? this is the key point of this requirement. thanks.

0 Max Robertson over 3 years ago in reply to Yue TANG

TI__Guru 62910 points

Yue,

In the network there needs to be a reference node whose polarity is considered correct. That node could set the polarity passively by including a pull-up resistance on A and a pull-down resistance on B, or it could set the polarity actively by driving a high state on the bus for a duration longer than the tFS parameter. You can read more about both techniques in Section 8.3.1 of the datasheet. For a non-master node, though, no special considerations are required in the schematic implementation. Please let me know if it is not clear.

Regards,
Max

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THVD1505: need a ref design of THVD1505