CMOSTEK CMT2300A - Power Consumption Specification

AN199
Rev 0.8 | Page 5/8
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1.2 配置 TX 的射频参数 Configure RF Parameters for TX
Followings need to be configured for TX.
 FREQ_VCO_BANK <2:0>
 FREQ_DIVX_CODE <2:0>
 FREQ_TX_N <7:0>
 FREQ_TX_K <19:0>
 FREQ_PALDO_SEL
Among them, FREQ_VCO_BANK<2:0> and FREQ_DIVX_CODE <2:0> are obtained in the same way as in
RX, that is, TX and RX share DIVX CODE and VCO BANK. If the target frequency bands are not the same,
when each time TX or RX is configured, recalculation and writing to these two registers is needed.
Then calculate the frequency of the LO (local oscillator), which is different from the LO frequency of RX. In the
formula below, FREQ_RF is the target RF frequency in MHz. FREQ_LO is the calculated local oscillator
frequency in Hz.
FREQ_LO = FREQ_RF x 10^6
Then calculate the value of the frequency word N.K, which is the same as the R.N.K value calculation
formula:
N.K = FREQ_LO x DIVIDER / 26MHz
At last, check the table below to get the value of FREQ_PALDO_SEL:
TX
Frequency
FREQ_PALDO_SEL
< 500 MHz
0
>= 500 MHz
1
举个例子，如果需要配置的 TX 目标射频频率是 433.92 MHz，根据上面的计算步骤，得出：
TX frequency FREQ_PALDO_SEL
< 500 MHz 0
>= 500 MHz 1
For example, if the target RF frequency for TX to be configured is 433.92 MHz, according to the above