Is external pull-down needed on SWCLK for nRF52?

[ScottBBBB]

My understanding is that the nRF51 is known to need a fairly stiff external pull-down resistor on SWCLK to avoid noise putting the chip into debug mode. I note that the nRF52 has an internal pull-down resistor; is this resistor sufficient to avoid the need to add an external one?

Thanks, Scott

[Hung Bui]

Hi Scott,

No, you don't need to have extra pull-down on the nRF52. The issue with noise on SWCLK on nRF51 was solved on nRF52. The sequence to enter debug mode on NRF52 now requires a power-up request, it's more noise resistance.

[ScottBBBB]

Thank you!