TIOS1013: Simulating TIOS1013 in PSpice-for-TI

Hi Danilo,

Unfortunately there isn't a PSpice model for this device that I can share with you.  The IBIS model can't be used in PSpice either for this purpose.

The first issue you are going to face is that the max TIOS1013 output rise/fall time is 150ns (under datasheet specs) which is too fast for the TVS3301 that has a max slew rate spec of 2.5V/us.  Just switching the TIOS1013's driver on can cause the TVS3301 to clamp.  We don't recommend using a Flat-Clamp diode on the output of the TIOS1013 and instead you will need a more traditional TVS diode.

In terms of simulation, you are essentially simulating the diode and not the TIOS1013.  You could replace the TIOS1013 with a transistor stack or a resistor to mimic the Rdson of the driver transistors.  You can then monitor the current through this resistor to determine if it will exceed the current limit you will set on the ILIM_ADJ pin of the TIOS1013, or if the voltage level exceeds the abs max rating which would trigger the ESD cells.  If the voltage level stays below the abs max, and the current through the driver (modeled as a resistor) doesn't exceed the current limit for longer than the current fault blanking time (tsc) which is approximately 200us or 175us min, then the TIOS1013 will not enter a fault condition.  

If the diode is working properly, then it will clamp and take the surge current protecting the TIOS1013 driver and ESD cells.

Regards,

Jonathan

Hi Jonathan,

Please see our customer's follow up inquiries below.

Thanks for the reply.

I would like to better understand your point regarding the interaction between the TIOS1013 output switching characteristics and the TVS3301 slew rate limitation.

You mentioned that the TIOS1013 output rise/fall time (~150 ns) is too fast for the TVS3301, which has a maximum slew rate of 2.5 V/µs, and that even normal switching could cause the TVS to clamp.

Could you please elaborate on the following points:

1. How exactly does the slew rate limitation of the TVS3301 lead to unintended clamping during normal switching (not surge conditions)?

2. Is the clamping triggered due to the internal control loop of the flat-clamp architecture responding to dV/dt rather than absolute voltage?

3. In such a scenario, would the TVS effectively behave like a load during switching transitions, thereby increasing current draw from the TIOS1013?

4. When you recommend a “traditional TVS diode,” should I specifically look for devices without active clamping control (i.e., avalanche-based TVS), and are there any key parameters I should prioritize (response time, dynamic resistance, capacitance, etc.) for compatibility with TIOS1013?

5. Since the TIOS1013 already has integrated surge protection, would that be sufficient to handle surge events in typical industrial conditions without an external TVS?

6. Before considering TVS3301, I was using an SMAJ30CA TVS diode. During surge testing, the TIOS1013 entered current fault detection mode. In your opinion, would a similar issue occur if I use TVS3301, or even if I rely only on the internal surge protection?

I want to ensure I fully understand the mechanism here so that I can select an appropriate protection strategy and avoid unintended fault triggering.

Regards,

Danilo

Hi Danilo,

Danilo A. said:

1. How exactly does the slew rate limitation of the TVS3301 lead to unintended clamping during normal switching (not surge conditions)?

2. Is the clamping triggered due to the internal control loop of the flat-clamp architecture responding to dV/dt rather than absolute voltage?

3. In such a scenario, would the TVS effectively behave like a load during switching transitions, thereby increasing current draw from the TIOS1013?

The TIOS1013 has a fast rise time which may be detected as a transient condition by the TVS3301 which will cause it to start clamping.  This will increase the current draw (acting as a load) and could lead to overheating from excessive current flowing out of the TIOS1013 through the TVS3301.  I will refer you to section 9.4.5 of the TVS3301 datasheet.

Danilo A. said:

4. When you recommend a “traditional TVS diode,” should I specifically look for devices without active clamping control (i.e., avalanche-based TVS), and are there any key parameters I should prioritize (response time, dynamic resistance, capacitance, etc.) for compatibility with TIOS1013?

Yes, exactly.  I'm not an expert on the finer details of TVS parameters because my expertise with with the TIOS1013.  I may refer you to the TSM36A (Link) and TSM36CA (Link) devices and suggest that you post your questions to a new E2E thread referencing the part number TSM36A or TSM36CA to get support from an engineer in our TVS protection group that will be better suited to answer these types of questions on specific diode parameters.

To prevent the TIOS1013 from seeing an over-current fault condition, the current draw through the OUT pin must be less than the configured current limit set on the ILIM_ADJ pin.  It is only allowed to be greater than this current limit for the blanking period which is approximately 200us.  So, the external diode must clamp and consume enough of the surge current to prevent and over-current pulse that is longer than 200us.

To avoid the TIOS1013 ESD cells from triggering and drawing a large amount of current, the voltage on the OUT pin must not exceed the Abs Max voltage specification of 65V.

Danilo A. said:

5. Since the TIOS1013 already has integrated surge protection, would that be sufficient to handle surge events in typical industrial conditions without an external TVS?

I don't know what level of Surge you are needing.  The TIOS1013 Surge rating is based on whether the device damaged during the surge event and not so much about whether it is disrupted by the surge pulse.  The TIOS1013 is rated to survive a surge pulse up to +/-1.2kV with a 500 ohm series resistance (not 42 ohms which is a common value for industrial surge requirements). 

Danilo A. said:

6. Before considering TVS3301, I was using an SMAJ30CA TVS diode. During surge testing, the TIOS1013 entered current fault detection mode. In your opinion, would a similar issue occur if I use TVS3301, or even if I rely only on the internal surge protection?

I don't know what diodes would be required to completely prevent the TIOS1013 from seeing an over-current condition.  I would suggest you post a question in a new E2E thread for the part numbers TSM36A or TSM36CA to see if they could handle this and get better guidance from engineers that directly support these types of devices.

Regards,

Jonathan