CSD87381P: Design Query

Ashish Kumar Pandey

Prodigy 95 points

Part Number: CSD87381P
Other Parts Discussed in Thread: TPS650864

Hi,

We are planning to use CSD87381P in our upcoming design.

We want to operate this device at Vin=5V. There is no clarity wrt Vin(input voltage) in the datasheet.

Kindly clarify.

Our application is based on document SWCS138D Section 8.3.

Regards,

Ashish Kumar Pandey

Research Engineer

CDOT-Delhi

over 2 years ago

0 John Wallace1 over 2 years ago

TI__Mastermind 29525 points

Hello Ashish,

Thanks for your interest in TI FETs. The CSD87381P will work with Vin = 5V. This device uses 30V FETs (minimum specified BVDSS = 30V) with abs max VGS rating of +10V/-8V. We have an excel-based TI synchronous buck FET selection tool available at the link below. It allows the user to enter their requirements and compare up to 3 TI FET solutions based on power loss, package and 1k price.

https://www.ti.com/tool/SYNC-BUCK-FET-LOSS-CALC

Best Regards,

John Wallace

TI FET Applications

0 Ashish Kumar Pandey over 2 years ago in reply to John Wallace1

Prodigy 95 points

Hi John,

Thanks for your response.

As per the CSD87381P datasheet the recommended Vgs range is 1.1-1.9 V .These parameters are out of range for the suggested calculator sheet.

Kindly provide calculator sheet for CSD87381P .

Regards,

Ashish Kumar Pandey

Research Engineer

CDOT-Delhi

+1 John Wallace1 over 2 years ago in reply to Ashish Kumar Pandey

TI__Mastermind 29525 points

Hi Ashish,

Thanks again for your interest in TI FETs. The Vgs range of 1.1-1.9V is the threshold voltage where the FETs just start to turn on and conduct 250μA. In order to fully enhance the FETs and guarantee on resistance, you must provide at least VGS = 4.5V (the PMIC provides 5V gate drive) as shown in the static characteristics table in the datasheet. I filled in the attached spreadsheet based on the gate drivers TPS650864 datasheet. I was not sure about your output current requirements and assumed 8A.

SYNC-BUCK-FET-LOSS-CALC_Rev1_Ashish.xlsm

Please let me know if you have any additional questions.

Best Regards,

John

+1 Ashish Kumar Pandey over 2 years ago in reply to John Wallace1

Prodigy 95 points

Hi John,

Thanks for your response.

Regards,

Ashish

Power management

Power management forum

CSD87381P: Design Query