SN74HC541: SN74HC541

06 4 Phase Encoder Schematic JPG partial.pdf

Upper left U1 is the chip I am sending TTL to, with no output resulting.

Test set CCA.pdf

This is the chip circuit I am trying to drive the SN54LS174 with.

Synchronizer output to 4 phase encoder.pdf

This circuit successfully drives the SN54LS174, but I thought the SN74HC541 chip would do the job.

Are you using TTL signals (which the SN74HC541 does not support), or 5 V signals?

What do you mean with "no outputs"? What is the voltage at the outputs?

Input to the SN74HC541 are 5V signals 0 to +5V transition, and +5V to 0 transitions. No outputs from SN54LS174 means zero volts on each of the Q output pins.

I didn't know the SN74HC541 did not support TTL. Output of the DAQ is used to source the signal with its own5V supply.

DAQ is set up for sourcing like this https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z0000019LhmSAE&l=en-US

With the load on the sourcing diagram being the input to the SN74HC541PW line driver chip.

Hi Hans,

Hans Kemmler said:

I am getting a good signal out of the SN74HC541PW, but when I apply these TTL signals to the 54LS174(Sold as PN JM38510/30106BEA ), I get no outputs.

Can you share waveforms at the input pins of the 54LS174? I'd like to see the clock, data, and clear signals together if possible.

TTL signals are not 5 V; the high level is about 3.3 V (depending on the load). But the V_IH of HC devices is 3.5 V.

Anyway, the DAQ does not output TTL signals, and should be fine.