RX3408 FM/FSK 500～20 MHz Receiver

The RX3408 is a low-power receiver chip that combines a UHF phase-locked loop (PLL) with an intermediate frequency (FM) receiver. The receiving section of the RX3408 is suitable as an orthogonal FM demodulator and a second intermediate frequency downconverter for wireless FM double conversion. When the internal PLL of the RX3408 is combined with an external VC0, it can be used as a local oscillator generator for home radio receivers (FRs) such as mobile communications. The PLL section of the RX3408 also includes an 18-bit programmable input frequency divider, a reference oscillator output buffer, and a standby enable controller that is serially programmed. 

The main technical features are as follows: 

・There are audio filters and noise reduction circuits on the chip; 

・Input frequency: PLL is 20 to 500 MHz, IF is 10 to 50 MHz; 

・FM/FSK demodulation method; 

・Data transmission rate is 2.4 Kb/s; 

・Sensitivity: PLL is -15 dBm, IF is -90 dBm; 

・The second intermediate frequency is 455 kHz; 

・Audio output is 180 mV/ms; 

・Operating voltage is 2.7～3.3 V; 

・Current consumption: 4.0 mA with squelch off, 5.4 mA with squelch on.

RX3400 Typical Application Circuit (Operating at 434 MHz)