TVS diode TPD6E05U06 for USB

[engr_joni_ee]

I am looking for ESD protection diode for USB. I found TPD6E05U06 which is unidirectional TVS. Does this mean that protection is only over positive voltages ? and not for negative voltages ?

From the datasheet the DC breakdown voltage is 6.5 V. How this is related or differ then Reverse stand-off voltage and Clamp voltage

 

[mtwieg]

I am looking for ESD protection diode for USB. I found TPD6E05U06 which is unidirectional TVS. Does this mean that protection is only over positive voltages ? and not for negative voltages ?

Yes, basically it behaves like a simple zener diode.

From the datasheet the DC breakdown voltage is 6.5 V. How this is related or differ then Reverse stand-off voltage and Clamp voltage

These terms are well-defined, I would read up on some app notes from manufacturers, like this one: https://www.st.com/resource/en/appl...amping-protection-mode-stmicroelectronics.pdf

Basically, these three voltages (VR, VBR, and VCL) are the voltages corresponding to three currents (IR, IBR, and IPP). These currents are usually some orders of magnitude apart (like 1uA, 1mA, and 10A), and give you a rough idea of where the transitions between different operating regions are.

 

[KlausST]

Hi,

Yes, basically it behaves like a simple zener diode.

I agree they act like zeners .... indeed.

But the OP asked:

Does this mean that protection is only over positive voltages ? and not for negative voltages ?

This can not be answerd with a YES.
It acts like a zener, thus it also protects against negative voltages.

***
* the functional block diagram is rather clear ... and usually does not need much explanation, if one knows how a diode and a zener works.
* 7.4 says: "The TPDxE05U06 is a passive integrated circuit that triggers when voltages are above VBR or below the lower diodes Vf (–0.6 V). "
* Figure 6-1 clearly shows protection (current) at negative voltage and positive voltage. Very steep V/I

***
The datasheet says "The TPDxE05U06 is a family of unidirectional Transient Voltage Suppressor ".
As non native English speaker - I find this expression somehow misleading.
For me it sounds like the "protection" is unidirectional (like the protection only works in one direction)
But instead the nominal (signal) working voltage is unipolar. (0V ... +5V)

So this protection device is good for signal voltage os 0..5V for example.

They are not good for RS232, because RS232 signals are positive as well as negative w.r.t GND.
And they are not good for RS485 receiver side: While the transmitter sends out signals usually 0V...5V w.r.t. transmitter_GND ... there is an allowed GND_biounce between Transmitter and receiver of +/-7V, making the valid input voltage at the receiver side: -7V ... +12V w.r.t receiver_GND.
***

So each applicaition has it´s requirements. Choose the protection device according these requirements.
Or look at the datasheet and check if they are designed for your application:
Like here the datasheet, page1, "2 Applications" lists:
• HDMI 1.4b
• HDMI 2.0
• USB 3.0
• MHL
• LVDS interfaces
• DisplayPort
• PCI-express®
• eSata interfaces
• V-by-One® HS

Klaus

 

[engr_joni_ee]

I am also wondering how the same ESD protection diode can be suitable for many applications mentioned on page 1 of the datasheet. These applications will have different voltage levels and ESD protection diode will have a particular characteristics for example breakdown voltage and clamping voltage then how it is suitable for these applications ?

 

[KlausST]

Hi,

for sure LVDS just has a couple of 100mV of signal level. But still the above protection device may be able to protect the driver / receiver IC. It depends on the circuit (maybe series resistors) and the ICs...

As an example: the datasheet of an LVDS receiver DS90C402 shows VCC_Abs_max of 6.0V and an input_signal_abs_max of VCC+0.3V.

the given protection device may fit to LVDS systems, but not necessarily to all LVDS systems. The electronics designer is still expected to read the datsheets. This is nothing special, I do it every day.

Klaus