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LM5101A: LM5101A

Part Number: LM5101A
Other Parts Discussed in Thread: LM5101,

Hello.

LM5101 finds problems in testing, and TI needs to help confirm.

When LM5101 is used, when the LM5101 5pin(HI) and 6pin(LI) level are low, the 3pin(HO) level output is high. The actual test is not the same as Datasheet.

LM5101  The input and output logic table is as follows

Best Regards

Leon

文晔集团

广东省深圳市南山区高新中三道9号环球数码大厦12

Mobile:(86)159 8985 2994

Tel:(86)755-26743880  Ext:6643

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  • Hi Leon,

    Thanks for asking about LM5101A, sorry to hear you are having issues, I am an apps engineer with this device and will help you out.

    Can I see a scope plot of HI,HO,HS during this issue?
    Can I see a the gate drive portion of the sch and operating conditions?
    what do you mean your test is not the same as the datasheet?
    can you resend the input and output logic table? I cant see it.

    Thanks,
  • Hi, Jeff

    Thank you for your support.

    The LM5101 circuit diagram

    LM5101 test conditions are as follows:

    Input=(10~80)V, Output=(0~80)V, LM5101 VDD=12V  

    Describe.: LM5101(5&6) pin is set to low level. Test LM5101 Pin3 (HO) is high. Test result cannot match logic table.

    cid:image002.png@01D3F6B3.C63187B0

    Verification method

    1. System board test: when MCU PWM output is set to low level. LM5101  (5& 6) pin is low level. Test LM5101 Pin3 (HO) is high as attached shows.

    2. Signal IC test: LM5101(5&6) pin short circuit to GND. LM5101 Pin3 (HO)  is high as attached shows

     

    For your questions, replied as below.

     

    Can I see a scope plot of HI,HO,HS during this issue?  ------as system board setup shows.
    Can I see a the gate drive portion of the sch and operating conditions? ------drive portion is as LM5101 SCH
    what do you mean your test is not the same as the datasheet? ------LM5101(5&6) pin is set to low level. Test LM5101 Pin3 (HO) is high. Test result cannot match logic table.
    can you resend the input and output logic table? I cant see it.---logic table is as above.

    Best Regards

    Leon

    文晔集团

    广东省深圳市南山区高新中三道9号环球数码大厦12

    Mobile:(86)159 8985 2994

    Tel:(86)755-26743880  Ext:6643

    Fax:(86)755-26743990

  • Hi Leon,

    thanks for the update, It seems that the LM5101 SCH and the logic table image was never sent. Can you upload them again?

    can you zoom in on LI pulse? and include HI,HO,HS in the same scopeshot with the same V/div?

    Thanks,
  • Hi, Jeff

    Thank your for your support.

    LM5101 circuit diagram is as follows:

    LM5101 Input/ Output Logic Table

    Sorry, I did not test the HS pin waveform.

    I tested LM5101A in client company to test the waveform of HI, LI, HO and LO.

    The waveforms of HI, LI, HO, and LO are as follows:

                                                                                           Signal IC set up.

    Test waveform of system board

    Best Regards

    Leon

    文晔集团

    广东省深圳市南山区高新中三道9号环球数码大厦12

    Mobile:(86)159 8985 2994

    Tel:(86)755-26743880  Ext:6643

    Fax:(86)755-26743990

  • Hi Leon,

    Thanks for your update. I notice that VCC goes to 25V. The recommended operating conditions for LM510x is up to 14V. Exceeding this limit can damage the part, in this case it seems to be damaging the highside output for some reason, maybe inrush the lowside output is not damaged.

    Thanks,