Posts: 5
Registered: ‎10-31-2016

Si4463, no responce after issueing si446x_power_up()


   For our project, we have a couple of prototype board that use a 4463CPCE30E915R pico board and a first version of our real hardware using SI4463.


Our C project will run the pico board based hardware but when we load it on our costume board.The radio will not respond after si446x_power_up(0x81, 0x81, RADIO_CONFIGURATION_DATA_RADIO_XO_FREQ); is run.


I modified the project to check CTS through spi interface after reset but before si446x_power_up(); and the radio responded with 0xff (ready)  looking at the bus on an o-scope, the SI4463 drive the bus strongly. After si446x_power_up(); and waiting 5 ms, the chip will not respond positively to the CTS query. Looking at the scope when the mcu issues the 0x44, the MISO line show a slowly rising voltage, then the MCU issues a 0x00 to read the response the the radio will drive the line low hard. I can put the check CTS in a loop and the radio will never respond after that.


We have copied the layout and BOM of the radio pico board 4463CPCE20C915 for our design.


Any ideas?

Posts: 320
Registered: ‎02-14-2014

Re: Si4463, no responce after issueing si446x_power_up()



The power supply timing requirements on p19 of the datasheet has to be complied to get reliable POR. Instead we recommend using the SDN pin to initiate POR.

As you can see on Figure 21. of AN633, end of POR can be detected by 6ms timeout or rising edge on GPIO1, but not with CTS on SPI.

To execute POWER_UP command, make sure your crystal is OK. (layout and part selection).

Note that the required crystal load capacitance is integrated on-chip to minimize the number of external

components, so by default all that is required off-chip is the crystal.


Silicon Labs
Posts: 5
Registered: ‎10-31-2016

Re: Si4463, no responce after issueing si446x_power_up()

Ok, I will take a look at that.