• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 376 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

OPA548: OpAmp to amplify current for Joule heating application

ArTzy
Mastermind 20330 points

Part Number: OPA548

Tool/software:

Hi Experts,

Customer is looking for solution to boost the 0.43V (<0.5A) signal up to 2A current for their joule heating application as per this config:

The fiber is a copper coil with about 3 ohm resistance, thus, need 2A to let it response fast.

Do you think the OPA548 can be part of this solution? If not, any solution to offer?

Thank you.

Regards,
Archie A.

  • +1
    TI__Guru* 77501 points

    Hi Archie,

    ArTzy said:
    The fiber is a copper coil with about 3 ohm resistance, thus, need 2A to let it response fast.

    Yes, OPA548 is able to drive 2A continuously. 

    To deliver 2A across 3ohm heater, it will require 6Vdc at the output. Assume this is non-inverting input, the following circuit should work. Please make sure that keep Vcc low as you are able, say 6Vdc + headroom + design margin, which is in an order of 10V-11Vdc. Higher the Vcc, more heat dissipation it will be across the OPA548. 

    OPA548 Driving 3ohm heater 10012024.TSC

    You would need to have good size of heat sink and/or cooling fan to dissipate approx. 10W of heat at OPA548. 

    Please pay attention to the SOA operating chart. 

    If you have other questions, please let me know. 

    Best,

    Raymond