SLLSFD6A May 2020 – March 2021 THVD8000
PRODUCTION DATA
Data at the D input is modulated with the carrier frequency (f0) via the F_SET pin. Figure 8-1 illustrates the modulation scheme. A high level at the D input is driven to the mid-level with zero differential voltage (VOD). A low level at the D input is modulated at the carrier frequency. It is recommended to use a carrier frequency that is 10x higher than the data rate. Higher data rates are possible at the expense of increased pulse width distortion with the use of lower ratios.
f0 is programmable by changing the external resistor (RF_SET) value connected to ground. Table 8-1 shows the carrier frequency for the each recommended resistor value.
RF_SET (kΩ) | OOK f0 (kHz) |
---|---|
77 | 125 |
50 | 187.5 |
19 | 500 |
12.5 | 750 |
9.3 | 1000 |
4.4 | 2000 |
1.5 | 5000 |
The oscillator used to generate the carrier frequency features spread spectrum clocking to reduce emissions.