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

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.

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