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TPUL1X1000-EVM: How to change trigger edge from Falling to Rising on

Ryan KIM
Prodigy 500 points

Part Number: TPUL1X1000-EVM
Other Parts Discussed in Thread: TPUL2G123

Hello team,

 

I just grab TPUL EVM. 

R1 is pull up resistor and it connected with 1Tn, 1T, 2Tn, 2T.

 

Our customer will use TPUL2G123 as a WDT IC.

(I try to follow "Designing with the SN54/74LS123" document)

image.png

So, it should be react by rising edge.

 

To change trigger edge from falling to rising.

image.png

I removed R1 resistor and connect 1Tn, 2Tn (K=1) to GND.

And Connect 1CLRn, 2CLRn to VDD without resistor. Connect 1T to MCU PWM pulse with pull down resistor.

I didn't connected another pins(2Q, 2Qn, 1Q, 1Qn... etc). 

 

After power on, Power supply runs like short circumstance.

Is there any problem on my circuit? Could you check what is wrong?

  • +1
    TI__Genius 10370 points

    Hi Ryan,

    You should not remove R1. Instead, you should remove R7 which is on the back of the EVM. That's where you should input your signal.

    Then, see the following table to see how to use the rising edge trigger and how it differs from the falling edge trigger:

    Regards,

    Nikki