Can the DT and SD functions of the ST2ED21091S be used simultaneously?

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manalishi
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Hi,

Can the DT and SD functions of the ST2ED21091S be used simultaneously?

I want to use shut down function by controlling DT/SD pin and want use dead time connection Rdt to DT/SD pin also.

The  programmable dead time (DT) function is working,  the driver IC should be shut down.

Data sheet says that DT/SD pin should not be pulled down and should not be floating to enable driver IC. 

If I pick up 100Kohm as Rdt and use 5V for DT/SD pin to control SD,  Is it enough to use 25Kohm as pull up resistor  to meet 4V (DT/SD maximum voltage is 4V)?

 

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Dipti_Kiran
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Hi,

Yes, the DT and SD functions of the 2ED21091S06F can be used simultaneously. DT/SD pin is a high impedance pin with two functionalities. When pulled lower than VSD,TH [Typ. 0.9V] the device is shut down. A voltage higher than VSD,TH  sets the dead time between high side gate driver and low side gate driver. The dead time value can be set forcing a certain voltage level on this pin i.e VDT/SD (Programmable dead time pin voltage) or connecting a resistor between pin 3 and ground. The maximum voltage level can be forced on DT/SD pin is 4V for setting the dead time.

Care must be taken to avoid below threshold spikes on pin 3 that can cause undesired shut down of the IC. For this reason, the connection of the components between pin 3 and ground has to be as short as possible. This pin cannot be left floating for the same reason.

Regarding your query:

If I pick up 100Kohm as Rdt and use 5V for DT/SD pin to control SD, Is it enough to use 25Kohm as pull up resistor to meet 4V (DT/SD maximum voltage is 4V)?

----->Either RDT or VDT/SD are chosen to set the dead time as per application requirements as explained above.

I am not able to understand your above query completely. Could you please elaborate?

Regards,

Dipti

 

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Dipti_Kiran
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Hi,

Yes, the DT and SD functions of the 2ED21091S06F can be used simultaneously. DT/SD pin is a high impedance pin with two functionalities. When pulled lower than VSD,TH [Typ. 0.9V] the device is shut down. A voltage higher than VSD,TH  sets the dead time between high side gate driver and low side gate driver. The dead time value can be set forcing a certain voltage level on this pin i.e VDT/SD (Programmable dead time pin voltage) or connecting a resistor between pin 3 and ground. The maximum voltage level can be forced on DT/SD pin is 4V for setting the dead time.

Care must be taken to avoid below threshold spikes on pin 3 that can cause undesired shut down of the IC. For this reason, the connection of the components between pin 3 and ground has to be as short as possible. This pin cannot be left floating for the same reason.

Regarding your query:

If I pick up 100Kohm as Rdt and use 5V for DT/SD pin to control SD, Is it enough to use 25Kohm as pull up resistor to meet 4V (DT/SD maximum voltage is 4V)?

----->Either RDT or VDT/SD are chosen to set the dead time as per application requirements as explained above.

I am not able to understand your above query completely. Could you please elaborate?

Regards,

Dipti

 

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Hi Dipti, 

Thank you for your kind answer.

The point of my question was how to set the Rdt to control the dead time when using a 5V SD signal
Your answer of adjusting the voltage to set the dead time resolved my question.

Best Regards

 

 

 

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