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LM5007: LM5007

GANTA SANTHOSH
Prodigy 10 points
Part Number: LM5007

Hi TI team,

We are using LM5007 converter 24-5V step down application.

While we are testing LM5007 at -35degC at no load Vout (output voltage)  is dropped to 1.5V, if load is on then vout changed to 5V.

In datasheet maximum temperature of junction mentioned -40degC.

We need to know what will happen if  LM5007 power on at -40degC

  • 0
    TI__Mastermind 35210 points

    Hello,

    Do you have a waveform at a higher temperature to demonstrate the issue only occurs at ~-40deg? Additionally, can your provide the schematic for review?

    In future waveforms provided, please try to include SW measurement as well.

  • 0 in reply to Marshall_Beck
    Prodigy 10 points

    Hi,

    We conducted no-load test at different temperatures -40,60degC.

    at 60 degC 

  • +1 in reply to GANTA SANTHOSH
    TI__Mastermind 35210 points

    Hello,

    This device does require a minimum load current of ~1mA. This can be ensured by selection of the feedback resistor. VFB/RFBB > 1mA.

    Could you share the schematic so I can verify that it is OK?

    Once we confirm that the schematic is OK, I would like to see if you can verify the fix and also measure Pin2 and Pin1 when doing so.

    7.3.8 Minimum Load Current A minimum load current of 1 mA is required to maintain proper operation. If the load current falls below that level, the bootstrap capacitor may discharge during the long off-time, and the circuit will either shutdown or cycle on and off at a low frequency. If the load current is expected to drop below 1 mA in the application, choose the feedback resistors with sufficiently low value to provide the minimum required load current at nominal VOUT.