LM74900-Q1: Voltage at HGATE

Shrey Gupta

Part Number: LM74900-Q1

Good afternoon

During the testing phase at no-load condition, I noticed that the HGATE driver is not being enabled, despite meeting the necessary conditions specified in the datasheet. Here are the measurements I have observed:

VIN = 26.5V
Voltage at the ENABLE pin: 26.5V
Voltage at the SLEEP pin: 26.5V
Voltage at the UVLO and OVLO pin: 0.7V
CAP to VS Voltage: 12.6V
Voltage at CTMR pin is 0V

Furthermore, the Ideal Diode MOSFET gate driver (DGATE) appears to be enabled, as indicated by a potential difference of 3.3V across the gate and source terminals of the DGATE FET. However, there is no potential difference across the gate and source terminals of the HGATE FET, indicating that it is not enabled.

Could you provide some guidance on why the HGATE driver is not being enabled ?

Thank You

2 months ago

0 Shiven Dhir 2 months ago

TI__Genius 11630 points

Hi Shrey,

Everything looks fine here.

Can you share schematic for me to find anything odd.

Regards,

Shiven Dhir

0 Shrey Gupta 2 months ago in reply to Shiven Dhir

Prodigy 115 points

Hello sir

The document you're looking for has been shared with you via private chat. Please check it and help me resolve this issue.

Thank you

0 Shrey Gupta 2 months ago in reply to Shiven Dhir

Prodigy 115 points

Good morning sir

"I'm also experiencing issues with an ideal diode using the IC LM5050, as I mentioned in another post (e2e.ti.com/.../5171230. I've already shared the relevant documents with you as requested, but I haven't received a response yet from your side. Please check on that too.

Thank you