74164 need help with led ?

[5282604]

hii,

i make aled matrix display but did i must use diver ( transistor ) with 74164 ?

can i direct connect 74164 with led by (100 ohm resistor) .

 

[erikl]

Depends on the 74164 type: LS types should be loaded by 8mA only, other types (S, HC, HCT) can drive 25mA. For these latter types you'd be rather safe with a 100Ω resistor, I'd think.

 

[5282604]

thank you :grin:

74ls164 i must to use transistor for driving led.
74(S, HC, HCT)164 direct connect with led by resistor only. max 25 MA

 

[rfredel]

Hello 5282604,

you can use SN7407 as buffer / driver. It has open collector and can 40mA.

regards

Rainer

 

[erikl]

you can use SN7407 as buffer / driver. It has open collector and can 40mA.

Right. Or 74241, 74244, 74541 to get 8 bit in a single package.

 

[5282604]

thank all