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  • LM117HVQML: Thermal Information

    Part Number: LM117HVQML

    Tool/software:

    Hello E2E Experts,

    Good day.

    The thermal information on page 4 of the datasheet does not mention the specific TO metal can package.

    Can you help verify which thermal metrics belongs to which TO can metal package?

    Regards,

    TICSC

    Power management forum Power management

  • LM117HVQML: 5962R9951705VXA

    Part Number: LM117HVQML

    Tool/software:

    Hello,

    I would appreciate some help to better model the thermal analysis for the LM117 voltage regulator. I am particularly interested in transient analysis rather than steady-state analysis. Here is an example of my MATLAB script for evaluating the junction temperature.

    % Simulation loop
    for i = 2:length(time)
    if time(i) <= t1
    P = P1;
    else
    P = P2;
    end
    % Calculate temperature change using thermal RC model
    dT = (P * dt) / C_th - (Tj - T_amb) * dt / (theta_JA * C_th);
    Tj = Tj + dT;
    temperature(i) = Tj;
    end.
    Where:
    P1 is the peak power portion
    P2 is the steady state power dissipation into the regulator
    t1 is the time period where the surge/peak power is present
    C_th is the thermal capacity of the TO-39 case + thermal adhesive + PCB
    Theta_JA, the thermal resistance junction to ambiant
    Here is a preliminary simulation result:
    Thank you for your help
    Best Regards
    Bruno
    Power management forum Power management

  • LM117HVQML: inquire about radiation performance

    Part Number: LM117HVQML

    Tool/software:

    I am currently working on a project that involves the use of the LM117HVHRLQMLV and LM124AWRLQMLV components.

    I would like to inquire about their radiation performance, specifically their sensitivity to the following radiation effects:

    • Displacement Damage Dose (DDD)
    • Single Event Latch-up (SEL)
    • Single Event Effects (SEE)
    • Single Event Burnout (SEB)

    While I found Total Ionizing Dose (TID) data in the datasheet, I could not locate specific information regarding the aforementioned radiation performance metrics. Could you please provide any available data or direct me to resources where I can find this information?

    Thank you for your assistance. I look forward to your response.

    Power management forum Power management

  • LM117HVQML: Maximum Power dissipation for LM117HRLQMLV (5962R9951705VXA)

    Part Number: LM117HVQML

    Tool/software:

    Hello,

    I would like to validate my understanding of the maximum power dissipation for the voltage regulator LM117HVQML. Based on the DSCC specification (https://landandmaritimeapps.dla.mil/Downloads/MilSpec/Smd/99517.pdf) , the absolute maximum power dissipation for my package (device type 05) is 2W. I understand that this 2W is likely calculated using the formula: PDmax=(TJ-TA)/thetaJA=(150-25)/64 =~1.95W

    This calculation assumes a 500 LFPM air flow.

    However, if I use a thermal adhesive between the PCB and the bottom of the TO-39 package, am I still limited to the 2W maximum power dissipation (which also needs to be derated)? For example, assuming: Pd=(TJ-T_PCB)/theta_PCB= (150-30)/40=3 watts. And you can assume that PCB temperature (T_PCB) is well mainted at 30degC in all time.

    So in that case Do I still have to use 2W as the maximum power disspation to be derated or I can start with 3W?

    Thank you for your answer

    Best Regards

    Power management forum Power management

  • LM117: LM117HVQML VS LM117HV/NOPB

    Part Number: LM117

    Tool/software:

    Looking to see if this part is a drop-in replacement.  I have the LM117HV/NOPB approved for my design but since its obsolete does the QML ending match up with the NOPB ending.

    Needs to be a direct drop in replacment

    thanks

    Power management forum Power management

  • LM117HVQML: Looking for Alternate for LM117H

    Tool/software:

    Hi,

    We have used the LM117H in our design, but it is now obsolete. We are currently looking for an alternative part to replace it.

    Regards,
    Mohd Ashad Khan

    Power management forum Power management

  • LM117HVQML: Stability analysis

    Part Number: LM117HVQML

    Tool/software:

    I'm having a hard time simulating a bode plot for this part. what is a typical method of verifying the stability of this part in the design? is it just through transient analysis? 

    Power management forum Power management

  • LM117HVQML: LM117HVQM

    Part Number: LM117HVQML

    내부 Bolck도에 D2, D3와 같이 Zener diode가 있어서 입력 surge에 대해 대책이 가능한지?

    Power management forum Power management

  • LM117HVQML-SP: Thermal Analysis

    Part Number: LM117HVQML-SP

    Tool/software:

    Disclaimer: Mechanical engineer trying to analyze electrical board.

    Looking for guidance on thermal analysis for this chip. Is the R_thetaJC taking into account the leads or are the leads in addition?

    For the analysis the chip is generating 3.5W in an environment of 71C in vacuum (all components are 71C when 3.5W starts). I do not have a good way to place a thermal gap pad, and I am limited to the 0.07mm copper ground plane in my board to route heat out of the chip, as there is no convection.

    I originally modeled as 2 bodies with the lower half having the R_thetaJC and the upper body having the R_thetaJA (still air). I am exceeding the 125C operational temp of this chip.

    Electrical Engineer suggested that a better model would be to separate into 3 bodies with a central conducting layer to the leads and insulating ceramic layers on top and bottom, but I am not sure what material to use to approximate the central layer.

    What is a good recommendation?

    Power management forum Power management

  • LM117HVQML-SP: Transients Above Rated 60V

    Part Number: LM117HVQML-SP

    Tool/software:

    Hi,

    I am using the LM117HVQML-SP in a system that can see input voltage transients of up to 75V. Can the LM117HVQML-SP take transients of this high, say if the transient is 75V, 20V/us, and 10us total pulse width? Can the regulator handle these types of transients, or would any input voltage above the rated 60V cause permanent damage?

    Thanks!

    Power management forum Power management

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