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TXDATA pin not responding

Category: Hardware
Product Number: ADF4159

Hello team,

In order to keep two ramp generating PLLs in sync, I enabled the TXdata trigger feature in TXdata section of ADF4158-9 GUI. One PLL was not responding i.e., ramp didn't start upon giving the TXdata Pulse upon selecting the Pulse TXdata option in GUI. 

I even provided a 1v8 supply externally at TXdata SMA connector of the Evaluation board but didn't respond.

Provided a 1v8 supply on the TXD pad of the evaluation board. Still no response.

I ensured that the voltage level didn't go beyond 1v8.

Is there any possibility of the trigger pin of PLL getting damaged by any means?

Under what circumstances the PLL cannot respond to TXdata pulse?

Note: Ramp signal is generating from PLL when keeping the TXdata trigger disabled. 

Thanks and regards,


  • When in continuous ramp modes, if ramping is enabled in Reg0[31] = 1 then the device will always be ramping regardless of any TxData pulses or the TxData trigger setting. The only way to stop a continuous ramp is to use the interrupt feature, or by setting Reg0[31] = 0

    When in single ramp/burst mode then TxData can be used to start a ramp. the TxData trigger setting needs to be enabled (Reg7[20] = 1), and ramping should be enabled by setting Reg0[31] = 1. In this setup the device will not be ramping until a pulse an the TxData pin which will cause the PLL to run through one burst. No further ramps will occur until another TxData pulse is detected, then another ramp will start, and so on.