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LM311: lm311 STRB and BALANCE pins

Part Number: LM311

Dear team,
The STRB and BALANCE pins of lm311 are not used, how to deal with them. Is it floating?

  • The remark in figure 17 says:

    If offset balancing is not used, the BALANCE and BAL/STRB pins must be unconnected. It is also acceptable to short pins together.

  • Hello T,

    The LM311-N (original National Semi) datasheet goes into a bit more detail (Application Hints, page 12, bullet #1):

    https://www.ti.com/lit/ds/symlink/lm311-n.pdf

    "The trim pins (pins 5 and 6) act as unwanted auxiliary inputs. If these pins are not connected to a trim-pot,
    they should be shorted together. If they are connected to a trim-pot, a 0.01 uF capacitor C1 between pins 5
    and 6 will minimize the susceptibility to AC coupling."

    There is also a bit more about guarding in section #5.

    So, yes, short them together as directly as possible, and keep any noisy lines away from the BAL pins.

    You can also tie 5 & 6 to V+ to increase the speed..with the resulting supply current and bias current increase.