The transmit chain uses the modulated output from the modem bank which directly modulates the fractional-N PLL. Anoptional pre-filtering of the bit stream can be enabled to reduce the power in the adjacent channels, also dependent onthe selected modulation type.The default maximum RF output power of the transmitter is +14 dBm for SX1261 and +22 dBm for SX1262. The RF outputpower is programmable with 32 dB of dynamic range, in 1 dB steps. The power amplifier ramping time is alsoprogrammable to meet regulatory requirements.The power amplifier is supplied by the regulator VR_PA and the connection between VR_PA and RFO is done externally tothe chip. As illustrated in Figure 4-3: PA Supply Scheme in DC-DC Mode, the supply used for VR_PA is different between thetwo circuit versions:• in SX1261: VR_PA, supplied through VDD_IN, is taken from a voltage regulator (DC-DC or LDO), allowing a very smallvariation of the output power versus supply voltage;• in SX1262: VR_PA, supplied through VDD_IN, is taken directly from the battery and in this case maximum outputpower is limited by supply voltage at VDD_IN