LM74700-Q1: about TVS didoe

Lee, Sam

Part Number: LM74700-Q1

Hi team,

I ask some questions about TVS dide when using LM74700-Q1.

When using one unidirectional TVS diode rather than bi-directional TVS in automotive VBAT=12V H/U application, can you explain which problem is expected?

For example, if a negative surge happens in the unidirectional TVS, will the TVS clamp to 0.7V as diode operation? In that condition, there will not be an issue? Otherwise, is it necessary to use bi-directional TVS in H/U application?

Thanks,

Sam Lee

over 3 years ago

+1 Divyanshu Vadehra over 3 years ago

TI__Expert 3370 points

Hi Sam,

In automotive applications, voltage surges can occur as both positive and negative voltage spikes. In case only a unidirectional TVS diode is used, it will only be able to protect against negative surges through avalanche breakdown or against positive surges through it's clamping action. But a bi-directional TVS diode is recommended to be used so that protection against both positive and negative voltage surges can be achieved.

For further information, kindly refer to section 10.1.1.3 of LM74700-Q1 datasheet: LM74700-Q1 Low IQ Reverse Battery Protection Ideal Diode Controller datasheet (Rev. G). Please let me know in case further clarification is required. Thanks for reaching out!

Best regards

Divyanshu

Power management

Power management forum

LM74700-Q1: about TVS didoe