NEED INFORMATION- OPA2277U/2K5G4

Hi Jayakumara,

Thank you for your inquiry.

For #5, #6 and #7, I am afraid it will take two weeks to answer.

 1. Junction Temperature Max (Tj Max) 

 Although absolute Max is 150[C], we estimate Ti Max as follws.

 Supply voltage = +/-15V, short circuit to GND  current is about 25mA (as shown in the spec sheet, page6)

  Pd = 15V x 25mA = 375mW

  Tj(Max) = Pd (Max) x ThetaJA + Ta(Max) = 375mW x 100C/W + 85C = 122.5C

 2. Typical Power dissipation (Pd typ)

 In condition of supply voltage = +/-5V, RL=2kohm, Vout=+/-3.5V (as shown in the spec sheet, page4) 

  a) power of Iq

      (+5v - (-5v)) x 0.79mA = 7.9mW

  b) power of output

      Output current is 3.5V / 2kohm = 1.75mA.

       ( 5V - 3.5V ) x 1.75mA = 2.6mW

  a) + b) = 10.5mW

 3. Maximum Power dissipation (Pd max) 375 [mW] ( as calculated above )

 4. Thermal Resistance Junction to Ambient (Theta JA) 100 [C/W] (as shown in the spec sheet, page4) 

 5. Thermal Resistance Junction to Board (Theta JB)

 6. Thermal Resistance Junction to Case (Theta JC)

 7. Weight

Best regards,

 Ichiro Itoi

Hi Jayakumara,

Here is the answer for #4, #5, #6 and #7.

 4. Thermal Resistance Junction to Ambient (Theta JA)

        SPEC SHEET: 150 [C/W] (as shown in the spec sheet, page4, SO-8 Surface-Mount) 

       Simulation: 91.9 [C/W]

 5. Thermal Resistance Junction to Board (Theta JB) simulation: 40.6 [C/W]

 6. Thermal Resistance Junction to Case (Theta JC) (top) simulation: 39.9 [C/W]

 7. Weight: 85.1 [mg]

     http://focus.ti.com/quality/docs/searchbyopn.tsp?templateId=5909&navigationId=11220&orderablePartNo=OPA2277U/2K5G4&pnType=A

Best regards,

 Ichiro Itoi