The Si4420/21 ISM band transceiver ICs are highly integrated, flexible, and low-cost solutions that do not require production alignments. They are ideal for high-volume two-way wireless applications, including remote control systems, home security and alarm systems, PC peripherals, toys, and automotive applications, including advanced remote keyless entry. Industrial applications such as telemetry, personal/patient data logging, barcode readers, and automatic meter reading are also supported.

The Si4420/21 have a completely integrated PLL for easy RF design, and their rapid settling time allows for fast frequency-hopping, bypassing multipath fading and interference to achieve very robust wireless links. The PLL’s high resolution allows for the use of multiple channels in any of the bands. Highly stable and accurate FSK modulation is accomplished by closed-loop modulation with bit rates up to 256 kbps. In addition to the FSK modulation features, the microcontroller clock, wake-up timer, low battery detector, output power level, and antenna tuning capability are also programmable through the serial interface.

*315 MHz band not available with Si4421