TPS51116: Soft start of TPS51116

Wendy Wang1

Part Number: TPS51116

Hi team,

If internal soft start of TPS51116 does not meet the requirements in the datasheet, will the corresponding protection mechanisms, such as overvoltage protection, overcurrent protection, etc., be triggered?

Best regards,

Wendy

over 2 years ago

0 Weidong Zhu over 2 years ago

TI__Expert 5965 points

Hi Wendy,

Can you elaborate what do you mean by internal soft start does not meet requirement in the datasheet?

Regards,

Weidong

0 Wendy Wang1 over 2 years ago in reply to Weidong Zhu

TI__Genius 11370 points

Hi Weidong,

For TPS5116, the internal soft-start sequence does not meet the requirement given in datasheet means that connect Pins ‘S3’ and ‘S5’ with Pin ‘V5IN’ together. What’s more, if connect Pin ‘PGOOD’ to external power (3.3V) directly (no any resistors), this wrong connection will trigger internal protection of TPS5116, thus, TPS5116 will not work. Is this description correct?

+1 Weidong Zhu over 2 years ago in reply to Wendy Wang1

TI__Expert 5965 points

Hi Wendy,

If you connect S3 and S5 to V5IN, the part should still work. It will power up both VDDQ and VTT when V5IN reach UVLO threshold, and will only turn off when you turn V5IN off.

However, if you connect PGOOD to external 3.3V directly, there is risk of damage the PGOOD pin when PGOOD is logic low. So a pull up resistor is definitely needed.

Regards,

Weidong

Power management

Power management forum

TPS51116: Soft start of TPS51116