TX7332EVM: Change TR Switch Clock Rate?

Kevin Huang5

Part Number: TX7332EVM
Other Parts Discussed in Thread: TX7332

Is it possible to change how often the TR Switches turn on and off using TI's provided GUI? By default the board sends out a pulse train every millisecond (1kHz). It looks like this is tied to TR_BF_SYNC which clocks at 1kHz - we would prefer to slow this down if possible.

over 4 years ago

0 Praveen Aroul over 4 years ago

TI__Mastermind 49666 points

Hi Kevin,

Yes, you have a couple of options to change the frequency.

First option is to change the CPLD code.

Second option requires a hardware change. You will need to remove R139 resistor on the TX7332 EVM and apply an external SYNC signal on U10 pin #3 using AWG.

0 Kevin Huang5 over 4 years ago in reply to Praveen Aroul

Prodigy 80 points

Would the external Sync signal just be a short pulse at the rate we need?

0 Praveen Aroul over 4 years ago in reply to Kevin Huang5

TI__Mastermind 49666 points

Can you let us know what signal (pulse width, rate) you are planning to apply?

0 Kevin Huang5 over 4 years ago in reply to Praveen Aroul

Prodigy 80 points

How low can the rate be and what range of pulse width should we be looking at? We are targeting around 250Hz or perhaps lower.

0 Kevin Huang5 over 4 years ago in reply to Kevin Huang5

Prodigy 80 points

Hello again,

I checked the datasheet and probed the pins. It looks like pin 3 is always held high at 1V and pin 2 is the one with the pulse. Should we be putting our own signal into pin 2 and not pin 3?

Also, how could we easily modify the CPLD's programming to change the sync pulse rate while still using the GUI without issues?

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TX7332EVM: Change TR Switch Clock Rate?