SI47XX-EVB Datasheet, PDF (19/164 Pages) Silicon Laboratories – Thank you for purchasing the Silicon Laboratories

2.2.3. Si474x Daughtercard
Si47xx-EVB
Figure 12. Si474x Daughtercard Connectors and Devices
Daughtercard connectors and components:
J4
BNC connector for antenna connection
C6, C1, C18
Vdd bypass capacitor
C2
FM matching component
L1, L5
FM matching component
Q1–2
Cascode amplifier for AM front-end boost circuit.
U1
Si4740/41/42/43 AM/FM Receiver chip
The daughtercard implements the Si4740/41/42/43 AM/FM RDS receive solution.
The Si474x daughtercard also has a cascode amplifier circuit made up of two transistors to provide gain boost for
AM front-end. The on-chip De-Q resistors will then be used to adjust the overall circuit gain. In cases where the AM
reception is too strong, the front-end attenuators can be engaged by using GPIO1 as the control signal.
Rev. 0.8
19