what is the expected Output at PAOUT pinout of ST25RU3993 UHF Chip.

[Kris1]

ST25RU3993 Firmware porting into STM32F407.

Observations, while ST25RU3993 Initialization.

-         Check SPI communication is ok .

-         Check EN pin + SPI communication is ok.

-         Check IRQ Line is ok.

-         Check Crystal is Stable.

-         Check PLL is Locked.

-         ST25RU3993 Initialize() is returns Zero.

                Configuration Parameters of ST25RU3993:

-         Internal Power Amplifier (Init PA).

-         Base Frequency : 867500 (867.5MHz).

-         Reference Clock Frequency : 50 KHz.

                  InventoryGen2() based scanning.

                 ETSI Mode Continuous Modulation is Kept.                    

Observed the Output at the PAOUT as Sequence of Pulses.

Query :

1.      Is Sequence of Pulses are Expected PIE(Pulse Interval Encoding)symbol Output at the PAOUT Pins(PAOUT_P,PAOUT_N).

2.      Can we Observe any Carrier Signal at PAOUT pins(PAOUT_P,PAOUT_N).  

[Bart Herse · Accepted solution]

HI,

1. at the PAOUT pins you will see the RF carrier ASK or PR-ASK modulated. The base band data is PIE encoded indeed.
2. PAOUT_P and PAOUT_N are differential output RF signals which need a matching network so that the output power is 20 dBm. The best point to observe the RF carrier (CW or modulated) with a spectrum analyzer would be right after the BALUN, when the RF signal is single ended referenced to GND.