CD74HC138: Y* output current

Dear Clemens

Many thanks for the answer. Based on my experience with SN74HCT138, the datasheet said "+-4mA output drive at 5V" at page 1, but the continuous output current , Io (Vo=0to Vcc) is +-25mA at page 4. The answer I received from TI's Dylan is 4mA for the output drive.

This is the similar situation that I need to know the value of the output drive current of CD74HC138. The datasheet showed "the continuous output current , Io (Vo=0to Vcc) is +-25mA" at page 3. At the same time, at the page 1, CD74HC138 showed the same fanout at LSTTL x 10 as SN74HCT138 did, but without specifying the "output drive current" specifically for CD74HC138. I need the decoder to drive a LED indicator together with enabling another decoder. 4mA is not so sufficient to do both.

The absolute maximum ratings shows how much current you can try to draw without damaging the chip.

The test condition in the DC electrical specifications table shows how much current you can draw while staying below the specified voltage drop.

If you have V_CC = 5 V and try to draw more than 4 mA but less than 25 mA, then the chip will not be damaged, but the voltage drop is not guaranteed and might be arbitrarily large.

How much current do you need?

20mA

The datasheet mentioned the fanout is 10 LSTTL. Can you tell me what the equivalent driving current is of CD74HC138?