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UCC27211A-Q1: Total gate charge needed by internal level shifter to operate

Part Number: UCC27211A-Q1

Hi team,

Can you provide the data for UCC27211A-Q1 related to total gate charge needed by internal level shifter to operate?

Best regards,

Foong Wei Seng

• Hey Foong Wei Seng,

Thank you for your question regarding the UCC27211A-Q1.

Are you asking about a minimum gate charge for the power FETs? Or are you asking about internal specifications of the level shifter?

Thank you,

William Moore

• Customer want to know the total gate charge for the level shift in the UCC27211A-Q1 to calculate the power dissipation in the gate driver theoretically.

• Hey,

We do not have a spec for this but the power dissipation for the gate driver can be calculated and determined using the quiescent current and the no load operating current at the desired frequency to determine the power dissipation of the gate driver itself.

The power dissipation calculations are seen in Section 9.2.2.5 Power Dissipation in the datasheet.

Let me know if there are any further questions.

Thank you,

William Moore

• Hello,

You said the power dissipation for the gate driver can be calculated and determined using the quiescent current and the no load operating current at the desired frequency, but there is no explanation for the loss of no load operating current at the desired frequency in Section 9.2.2.5.

I can only see the loss from the quiescent current and gate charge as shown below.

Then, could you answer the following questions?

1. How can we calculate the loss of no load operating current at the desired frequency?
2. We can see three kinds of quiescent current and three kinds of operating current. Should we consider all kinds to calculate the loss accurately?

3. I wrote down a equation for the loss of the gate driver below. Is it correct?

When a gate driver is not switching: P = (IDD+IHB+IHBS)*VDD

When a gate driver is switching: P=(IDDO+IHBO+IHBSO)*VDD + Qg*VDD*Fsw (gate charge loss)

Best regards,

Foong Wei Seng

• Hey,

1. For the operating current, please refer to Figure 3 and Figure 5 in datasheet Section 7.7 Typical Characteristics.

2. For the quiescent current and operating currents, you need to factor in all 3 currents for each condition.

3. For these loss equations, these equations are correct.

Thank you,

William Moore