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CD4077B: How maximum current is IOL and IOH?

Kengo.Y
Guru 11245 points
Part Number: CD4077B
Other Parts Discussed in Thread: CD4011B

Hi team.

I'd like to know about CD4077B.

1.How maximum current is IOL and IOH?

2.Does it have a maximum current spec for all pin total?

Sincerely.

Kengo.

  • 0
    TI__Expert 6680 points

    Hi Kengo,

    The datasheet for the CD4077B gives ratings on all sourcing & sinking currents, as well as quiescent & input currents on page 4.

    It also goes into detail about the IOL & IOH, but I'm afraid I don't understand what you're asking.

    Thanks!

    Chad Crosby

  • 0
    Guru 316690 points

    It appears Harris did not bother to specify these in the Absolute Maximum Ratings.

    The datasheet for some similar gate (NAND: CD4011B) specifies the maximum power dissipation per output and per package. Figures 3 and 5 shows that it is easily possible to exceed it, but only at supply voltages higher than 5 V (at 5 V, the output impedance is about 1 kΩ, and the short-circuit current is too low to be dangerous).

  • 0 in reply to Clemens Ladisch
    Guru 11245 points

    Hi Chad and Clemens.

    Thank you for your reply.

    The CD4011B has a description of 100mW.

    I think it is 100mW per output. Is it correct?

    How to calculate is maximum output current?

    Max output current = 100mW / VDD 

    Is it correct?

    Sincerely.

    Kengo.

  • 0 in reply to Kengo.Y
    Guru 316690 points

    It is 100 mW per output, and 500 mW per chip.

    This limit is on the power dissipation of the output transistor. The voltage drop over the output transistor is VDD only if a high output is shorted directly to GND, or if a low output is shorted directly to VDD. If some voltage is dropped over the load, then only the remaining voltage is dropped over the output transistor.