• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 31 subscribers
  • Views 369 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

OPA1679-Q1: OPA1678 / OPA1679 - WSON-8 / QFN Package Thermal pads - can they connect to GND as well?

Aditya Nandwana
Prodigy 40 points
Part Number: OPA1679-Q1
Other Parts Discussed in Thread: OPA1678, OPA1679, TINA-TI

The datasheet for OPA1678 specifies -V. I've looked hard through the OPA1679 datasheet but do not see a signal specified. I was curious to know if GND can be used instead or if that will create issues.

The circuits I plan to use these opamps in run between +/-12V and +/-18V. The ground planes have significantly better thermal conductivity than V-, which may or may not be on a separate signal layer.

Thank you for your time answering this possibly amateurish question. I'm trying to create a library for these parts in EAGLE so I'd like to get the pin assignments right on the part itself.  

  • 0
    TI__Mastermind 23550 points

    Hello,

    I have reached out to our designer who is on holiday until the 11th. I will have an answer regarding this question in a few days. Thank you for your patience. 

  • +1
    TI__Guru 64380 points

    Since OPA1678 (dual) and OPA1679 (quad) are fabricated on the same silicon process, they are electrically identical.  For this reason, the thermal pad of both package versions should be connected to a negative rail - this is because the wafer fab p-substrate is biased at the negative rail.

    Since you want to take advantage of better thermal performance of PCB ground plane, you should configure the circuit to work on a single supply by ac coupling the input signal so your ground plane is the same as negative supply - see below.

    Below I have attached Tina-TI schematic for your own simulatons.