SLOS743M August 2011 – March 2020 TRF7970A
PRODUCTION DATA.
This command can be used in active mode when the RF receiver is switched on but RF output is switched off. This means bit B1 = 1 in Chip Status Control Register. The level of RF signal received on the antenna is measured and displayed in the RSSI Levels and Oscillator Status register (0x0F). The relation between the 3 bit code and the external RF field strength [A/m] must be determinate by calculation or by experiments for each antenna type as the antenna Q and connection to the RF input influence the result. The nominal relation between the RF peak to peak voltage in the RF_IN1 input and RSSI code is shown in Table 6-23 and in Section 6.5.1.2.
NOTE
If the command is executed immediately after power-up and before any communication with a tag is performed, the command must be preceded by an Enable RX command. The Check RF commands require full operation, so the receiver must be activated by Enable RX or by a normal Tag communication for the Check RF command to work properly.
RF_IN1 [mVPP] | 40 | 60 | 80 | 100 | 140 | 180 | 300 |
Decimal Code | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
Binary Code | 001 | 010 | 011 | 001 | 101 | 011 | 111 |