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LM2660: Inquiry about the Datasheet of LM2660.

Grady Lee
Genius 4355 points
Part Number: LM2660
Other Parts Discussed in Thread: LMC7660, LM2776

Hi, TI expert.

When a customer puts a 5V input for the purpose of reviewing the negative power of the opamp, we are reviewing the power device that outputs (-)5V output, and the output more than 50mA.

So, the customer is planning to review the LM2660.

Opamp will use MIC920 (Microchip).

The corresponding OPAMP is switching to 20MHz.

In other words, it pulls the power current to a frequency of 20MHz. In this regard, is there any part of the power supply IC datasheet that should be looked at carefully?

(For example, switching frequency, etc.)

please answer about my question.

Thank you.

  • 0
    TI__Guru 67685 points

    Hello Grady,

    LM2660 switches either with 10kHz or 80kHz. So the device will not react on load drawn at 20 MHz. You need to add enough output capacitance to make sure that the load can be supported. If the maximum load is 50mA, I think the standard application is fine.

  • 0 in reply to Brigitte
    Genius 4355 points

    Hello Brigitte

    Thank you for answer.

    Since it does not respond to 20MHz load, is it correct that it is possible by adding enough output capacitors?

    Is there anything I need to look at carefully in the datasheet?

    In addition, I would like to review the LMC7660 and LM2776, are they the same as the LM2660?

    please answer about my question.

    Thank you.

  • 0 in reply to Grady Lee
    TI__Guru 67685 points

    Hello Grady,

    Yes, the output capacitance will need to be big enough to support the load and you might add a smaller capacitor that is still capacitive at this frequency to stabilize the output.

    In general for charge pumps the layout is important, so this section is for sure important. The application section will give a lot information on what and how to connect the external components, so it makes sense to review this as well. In general charge pumps are simple switching converter.

    The devices you mention are similar, but not exactly the same.