TIDUDO6B May 2019 – October 2020
Figure 2-3 shows the schematic for configuring the CC2640R2F MCU.
The VDSS power supply for the MCU, 2.1 V, is derived using the TPS63036 device. The VDDR power supply is generated using the internal DC/DC of the CC2640R2F MCU, and L8, C20, C25, and C27 form the filter components for the same. Y1 is the 24-MHz, high-frequency, external clock and Y2 is the 32-kHz, low-frequency, external clock. The GPIO pins of the CC2640R2F MCU (DIO_0 to DIO_30) interface with different functions such as Memory interface lines, AFE4900 interface lines, SPI communication, LED drives, and so on.
The RF front end is used in differential-ended configurations with internal biasing. A Balun LFB182G45BG5D920 device is used for the RF front end and tuned for application. J7 is a connector for conducted RF measurements (if required). The antenna is a PCB antenna.
VBATT is connected to VDSS through L5 (a GHz noise-suppression chip ferrite bead), providing a low-noise supply to the MCU. C19 and C22 are the decoupling capacitors. A 2.1 V is connected to the VDDS2 and VDDS3 pins through L6 (a GHz noise-suppression chip ferrite bead), providing a low-noise supply to the MCU. C23 and C24 are the decoupling capacitors (see Figure 2-4).
The MCU is programmed using a JTAG connection, as shown in Figure 2-5. The connector inputs are protected by ESD diodes (TPD1E10B06DPYR) from Texas Instruments. The TPD1E10B06 device is a single-channel, ESD, TVS diode in a small 0402 package. This TVS protection product offers ±30-kV contact ESD, ±30-kV IEC air-gap protection, and an ESD clamp circuit, with a back-to-back TVS diode for bipolar or bidirectional signal support.