Selecting of nRF52840 SoC package

[Moghees]

Hi,

We want to build PCB using nRF52840. Previously we were using this package but it is out of stock. I want to ask can we use this instead of the previous package. Are they both the same in footprint so I can directly replace one with another?

Another question can we use aQFN package in 2 layer design and access its inner pins(e.g P0.18, P0.25) on the top layer?

Like below:

Regards,

Moghees Bin Zahid

[ketiljo]

All devices with the same version code, like QIAA, will have the same pinout and footprint. The order code may differ, but this is mostly the distributor that is changing that. R and R7 are both ree, 13" and 7". See https://infocenter.nordicsemi.com/topic/ps_nrf52840/ordering_info.html#order_codes

You need an inner layer and via in the pad to access the inner row of pins

[Moghees]

Let me rephrase my question:
I have designed version 1 of PCB using nRF52840 chip having package QFN73, and have accessed P0.18/RESET pin on the top layer it is working fine but it is now out of stock. I have another nRF52840 chip available but its package is aQFN73, I want to ask if in the aQFN73 package we can access P0.18 and P0.25 on the top layer as I was able to access it with the QFN73 package in my version 1?

[ketiljo]

The nRF52840 only comes in aQFN73 packet. If it says QFN73, it's misspelled. 

These are the only variants:

[Moghees]

ok could you kindly take a look at following nRF52840 chips and confirm me if in place of one other can be used?

1) https://lcsc.com/product-detail/RF-Transceiver-ICs_Nordic-Semicon-NRF52840-QIAA-R_C190794.html

2) https://lcsc.com/product-detail/RF-Transceiver-ICs_Nordic-Semicon-NRF52840-QIAA-R_C190794.html

[ketiljo]

They are identical. There are only one 73 pin package available for this device. If you are in doubt, you must ask the distributor. 

[Moghees]

ok thankyou