The PT4305 is a PLL-tuned FSK receiver for short-range wireless data applications in the 315 MHz and 434 MHz frequency bands. The PT4305 offers a high level of integration and only requires few external components.
The PT4305’s receive section includes a low-noise amplifier, image-reject mixer, IF band-pass filter, limiting amplifier, and frequency-shift keying (FSK) demodulator and also includes automatic gain control (AGC). A switched-capacitor data filter further filters the signal after the demodulator before a slicing comparator restores the data to full-swing CMOS logic levels.
The local oscillator sub-system consists of a phase-locked loop (PLL) based on a crystal oscillator reference. The receiver channel frequency is determined by the choice of the crystal frequency.
A built-in voltage regulator provides improved power supply rejection (PSR) and extends the supply voltage range from 2.4 V to 5.5 V.
The PT4305 is available in a 16-pin SSOP package and its operation is specified over the temperature range from –40 to +85°C.