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LM224: Lm224 temp at 100°C

Otmar Glaser
Prodigy 10 points
Part Number: LM224
Other Parts Discussed in Thread: TLV170, LM2902, TS321, , LM2902KAV

we want to use the LM224 at a Ta. of 100°C under following condition

3 OPAMP very low current

1 OPAMP only 5 MA sink

supply voltage 15V

can we use this part for Ta.=100°C?

is there other disadvantage at Ta.=100°C?

  • 0
    TI__Mastermind 30600 points
    Hi Otmar,

    This part is not rated for 100°C ambient temperature, you can consult the recommended operating conditions table (6.3) to see this.

    If you'd like a part that will be able to operate at 100°C, I would recommend the TLV170 - it's rated for 125°C operating. At higher temperatures, you'll have higher offset voltage and other parameters will shift as well.

    -Paul
  • 0
    TI__Guru**** 150966 points
    Otmar,

    LM2902 is rated for 125C.
    Is there a special reason for wanting to use LM224?

    Output dissipation is about 1V * 5mA = 5mW; Quiescent current dissipation 15V * 1.4mA = 21mW
    Package type and board characteristics will affect final die temperature.

    If you only need one amplifier, try TS321
  • 0 in reply to Ron Michallick
    Prodigy 10 points

    Dear TI

    The given answers which I got do not satisfy me.

    I want to use the LM224A because the offset voltages are lower than in LM2902 types. I need a quad Opamp.

    Unfortunately my Ta is 100°C (15K higher than LM224A is rated).

    Fortunately my power losses in the LM224A is lower than in the datasheet allowed: only 1 amplifier makes losses: Vout is 1V, Isink is 5mA, Vcc is 15V.
    The other 3 amplifiers are used but the output current is < 1mA. --> intern losses very low.

    question 1: how high is the allowed Tjunction max intern for the LM224A?

    question 2:  how much intern losses are allowed @Ta 85°?

    question 3: how much intern losses are allowed @Ta 100°?

    question 4: how much intern losses are allowed @Ta 115°?

    question 5: How do you calculate the intern losses? Vout is 1V, Isink is 5mA, Vcc is 15V.

    Thanks in advance Dietmar Kiefer, Delta Energy Systems Teningen

  • 0 in reply to Dietmar Kiefer
    TI__Guru**** 150966 points
    Dietmar,

    LM2902KAV is the 125C low Vio version device in this product family.

    Absolute maximum junction temperature is 150C; this temperature results in reduced expected lifetime.
    Internal power loss is Vcc * Icc where Icc is the quiescent current that doesn't include load current.
    Internal power loss from loads is (VOUT - GND) * IOUT when sinking current.
    Internal power loss from loads is (VCC - VOUT) * IOUT when sourcing current.
    Add up the three losses to get a total power loss.