• State TI Thinks Resolved
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 13 views
  • Users 0 members are here
Support feedback
Options
Options
Related

LP2951-Q1: Question about LP2951-50QDRQ1

Chase Jeong
Mastermind 7425 points
Part Number: LP2951-Q1

Tool/software:

Dear TI experts,

My customer have some questions about LP2951-50QDRQ1. Could you check these questions?

1. Is it necessary to connect FEEDBACK pin to Vtap for fixed output part? What would be happen if I do not connect FEEDBACK and Vtap?

2. About current limit (section 6.3.3 of dcatasheet), What is the temperature that causes thermal shutdown?

and how long does it take to real shutdown after specific temperature arrived?

(i.e. Device will be shutdown after it reaches 150 degree tjc.)

3. Does this device have over voltage protection? if not, may I know the reason? (because it is important to protect the device.)

Please check this issue.Thanks.

Best regards,

Chase

  • 0
    TI__Genius 13640 points

    Hi Chase,

    Chase Jeong said:
    1. Is it necessary to connect FEEDBACK pin to Vtap for fixed output part? What would be happen if I do not connect FEEDBACK and Vtap?

    Yes, this is required. SENSE and VTAP form an internal resistor divider circuit with respect to GND as shown in 6.2 (Functional Block Diagram). When using the Fixed Vout option, If FEEDBACK is not connected to VTAP, the error amplifier will not sense the output voltage and regulation will not be possible. Output voltage state will depend on how OUT and FEEDBACK are connected, likely indeterminate.

    Chase Jeong said:
    2. About current limit (section 6.3.3 of dcatasheet), What is the temperature that causes thermal shutdown?

    Tj max is when the device reaches shutdown. This is 150 degC

    Chase Jeong said:
    how long does it take to real shutdown after specific temperature arrived?

    About 500 us

    Chase Jeong said:
    Does this device have over voltage protection? if not, may I know the reason? (because it is important to protect the device.)

    This device does not have OV protection on input or output. The abs max values are sufficient enough to handle typical OV cases but also any OV case on IN will not affect the OUT so long as regulation is maintained and abs max is not violated unless thermal shutdown kicks in and disables the device.

    Thanls

    Ishaan