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

XOUT

XIN

SEL1

SEL3

STBY

SEL2

MSTAT / OUT0

÷

RST

GND