LM4120: Negative Output Circuit

Part Number: LM4120

Has anyone else tried the Negative Output Circuit for this regulator, as shown on Figure 19 of the datasheet? We've been trying to get this to work consistently, but it's only worked a few times. It works fine for the positive output circuit, though.

2 Replies

  • Hi Cheryl,

    What values are you using for the input capacitor and resistor from Figure 19? Additionally, are you using any load capacitors? That figure doesn't show one, but I believe the part still needs a load capacitor for stability (between Vout and GND, like in Figure 29).

    What about the values in the positive output case (Figure 29)?

    Regards, Diego Lewis
  • In reply to Diego Lewis:

    Hi Diego,

    I'm using a 1K resistor and 0.1uF capacitor, like Figure 19 suggests. There's no load capacitor, but I'll try it and see if that works.

    The positive output case works fine.

    Thanks,

    Cheryl