4.1 Transmitter

The IS2083BM has Lower Power Amplifier (LPA) and Medium Power Amplifier (MPA). The MPA supports up to +11 dBm power level for Bluetooth Class1 configuration and LPA supports up to about +1 dBm power level for Bluetooth Class2 configuration. The MPA output is connected to the PA1OP pin of the SoC. The LPA output and LNA input are multiplexed and connected to the RTX pin of the device.

The IS2083BM supports shared port configuration, in which the MPA and LPA pins are wired together as shown in the following figure. In shared port configuration, the external series capacitors on RTX, PA1OP pins and PI filter circuit implements a low BoM cost solution to combine the MPA and LPA/LNA signals. Typical value of these components are C1 = 2 pF, C2 = 3 pF, C3 = 1.3 pF/1.4 pF, L1 = 2.7 nH/2.8 nH, C4 = 3 pF (use the BM83 RF schematics as it is to achieve the desired RF performance).

Note: For more details, refer to the IS2083 Reference Design Application Note.
Figure 4-1. Shared Port Configuration