Si4356
Rev 1.2 13
4. Functional Description
Figure 3. Si4356 Functional Block Diagram
The Si4356 is an easy-to-use, size efficient, low current wireless receiver that covers the sub-GHz bands. The wide
operating voltage range of 1.8–3.6 V and low current consumption make the Si4356 an ideal solution for battery
powered applications. The Si4356 uses a single-conversion mixer to downconvert the (G)FSK or OOK modulated
receive signal to a low IF frequency. Following a programmable gain amplifier (PGA), the signal is converted to the
digital domain by a high performance ADC, thus allowing filtering and demodulation to be performed in the
built-in DSP and increasing the receiver's performance and flexibility versus analog based architectures. The
receiver demodulates the incoming data asynchronously by oversampling the incoming transmission. The resulting
demodulated signal is output to the system MCU through data output pin RX_DATA.
Integrated configuration tables allow the Si4356 to be completely configured using the four selector pins. The state
of each of these pins is read internally at startup and used to determine which pre-loaded configuration should be
used. The Si4356 then loads this configuration without the need for any external MCU control.
The Si4356 includes an integrated crystal oscillator. The design is differential with the typical crystal load
capacitance integrated on-chip to accommodate a 30 MHz off-chip crystal.
Rx Modem
Synthesizer
LNA
PGA
ADC
Rx Chain
Configuration Decoder
30MHz XO
RXp
RXn
VDD SEL0
CLK_OUT
RX_DATA / OUT1
XOUTXIN
SEL1 SEL3
STBY
SEL2
MSTAT / OUT0
÷
RST
GND
