Some doubts about nrf24ap2 hardware reference circuit.

RE: Some doubts about nrf24ap2 hardware reference circuit.

ArthurJHChen — Fri, 02 Nov 2018 05:45:37 GMT

Hi Ketiljo:

Item 4:

If we want to use a diplexer, how about that attenuation require?

Could you help check two part as below which one you suggest? Or you have recommend part?

EPCOS: B39162B8636P810

TDK: DPX205850DT-4052B3

Thanks a lot!

RE: Some doubts about nrf24ap2 hardware reference circuit.

WrightLin.Avnet — Tue, 30 Oct 2018 12:30:11 GMT

Hi Ketiljo:

Thanks for your great reply! It's help a lot!

RE: Some doubts about nrf24ap2 hardware reference circuit.

ketiljo — Tue, 30 Oct 2018 08:45:07 GMT

1. VDD_PA is the power supply to the PA. There must be a DC path between this pin and both ANT pins. Hence the inductors L1 and L2.

2. In synchronous mode, UART_TX and UART_RX should be tied to GND or VDD, see the the pin function, chapter 2.4 and Host interface, chaper 5 in the datasheet.

3. All necessary decoupling capacitors are shown in the schematic.

4. The GPS uses a different frequency, 1575 MHz, so unless you find a antenna that covers both band, it's not possible. In any case, the attenuation in a diplexer isn't good enough to allow for GPS receiving when the AP2 is transmitting. The GPS sensitivity is very high so it's not easy to share the antenna with anything else.