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LMZ23610

user5006944
Intellectual 630 points
Other Parts Discussed in Thread: LMZ23610, LMZ14203H, LMZ14203

The output voltage range0.6-6V.Now my output voltage is 8V.there is no problem.Also, The input voltage range is 6-36V,why the output voltage is so low.

I would like to know  the risk when I output voltage is  8v.

  • 0
    Intellectual 630 points
    My input voltage range is 12V-20V.
  • 0 in reply to user5006944
    TI__Intellectual 1535 points
    LMZ23610 has been designed for an output voltage between 0.8V and 6V.
    When the part is overstressed beyond this borders, the proper functionality is not given.
    The device could be damaged irreversible. Several other failures can occur before, for example instability of the regulation loop.

    For your application I would recommend the LMZ14203H which is a part that was designed for higher output voltages up to 24Vout.

    If you have more questions please don't hesitate to ask!

    Best regards,
    Michael
  • 0 in reply to Michael Daimer
    Intellectual 630 points
    But the output current of LMZ14203 is only 3A
  • 0 in reply to user5006944
    Intellectual 630 points
    I want to know that Whether the internal circuit is limited or dissipated power problems, such as internal inductance saturation factors, etc. At present my application is 8V8A, I would like to understand the true and the internal principle of not reaching 8v or higher
  • 0 in reply to user5006944
    TI__Intellectual 1535 points
    Yes sorry, my fault. Forgot that your application needs up to 10A? Is that right?

    As you mention, probably the inductor and the IC are not rated for such high voltages or output powers.

    It might be the case that your application works right now, but stressing the device beyond its limits may cause permanent damage to it. The functional operation of the device can not be guaranteed under these stress conditions.

    Image you drive a hand shifted car and the motor rotation speed is always in the red area. The car will drive, but how long? The engine suffers from this operation mode and the probability that the engine will be destroyed within a short time is quite high.

    I did a quick research and unfortunately found no module that fits with your requirements.
    Utilize Webench and have a look at the suggested options.

    Best regards,
    Michael
  • 0 in reply to Michael Daimer
    Intellectual 630 points
    Thanks for your answer.But I want to know the internal principle,Can you help me ask the designer of LMZ23610.
  • 0 in reply to user5006944
    TI__Intellectual 1535 points

    I talked to some engineers and there are some additional points I can give you.

    The device might be able to operate with your requirements, nevertheless functionality is not guaranteed.

    1. Thermal limits

    Be sure that thermal limit is not exceeded. The maximum junction temperature is 150C. The device will go into thermal shutdown at 165C and will turn on again with a hysteresis of 15C (see datasheet point 6.5.). So you have to make sure that your application provides enough cooling capacity.

    2. Current limits

    The current limit section in the datasheet (refer to section 7.3.4.) says that current is sensed through the low side FET and the high side FET.

    The overcurrent shut off for the low side is 13A and for the high side is 16A as typical values.

    Depending on your input voltage and switching frequency you have different ripple currents. I calculated some for you.

    These are peak to peak values in ampere. So depending on your conditions you might reach current limit and the device turns off.

    The following picture shows you as an example the current through the low side FET with 20V input, 8V output @ 360kHz switching frequency.

    With this conditions or some other conditions, the current limit might be triggered (13A is a typical value, it can be slightly below).

    You can use the Power stage designer tool to calculate these values and it also gives you some graphs. Perhaps this can help you.

    Here is the link: www.ti.com/.../powerstage-designer stage designer&tisearch=Search-EN-Everything

    3. Stability

    Stability could also be a problem.

    It might be the case that your line regulation is not the best. So your output voltage of 8V could swing by some mV.

    Also the load regulation could be problematic, so that your output jumps, when a load transient occurs.

    This behavior can be tested with the EVM and you can decide, if the performance is god enough for your desired application.

    Hopefully these points help you.

    Best regards,

    Michael

  • 0 in reply to Michael Daimer
    Intellectual 630 points

    Dear Michael,

           Thanks for your answer.Now I have another problem, that is, when I put the output voltage of 5V, the outut short circuit and then open and found that there will be 100us output of more than 10V.

    Best regards,

    Shaopeng