Block Diagram

matching
network
connector
LDO = low-dropout regulator
PCB shield
5V +/- 0.5V
U1
LDO
3.3V analog/digital
I2C bus (SDA & CLK)
I2C buffer
CF1A
button
CF2A
digital part, not part of radio device
U2
U3
PN7150
SB10
DL7-DL16
connector
PCB coil antenna
+/-0.15V