FSK Transceivers Operate In ISM Bands

A pair of single-chip frequency-shift keying (FSK) transceivers are aimed at telemetry, security and low data-rate applications in the license-free Industrial-Scientific-Medical (ISM) bands. The MICRF500 operates from 700 MHz to 1 GHz, while the MICRF501 covers the 300- to 600-MHz range. The MICRF500 covers the European 868-MHz ISM frequency and U. S. 902- to 928-MHz band, whereas the MICRF501 is ideally suited for the 433-MHz European ISM band and the 300-MHz ISM band in the U. S. The primary application is bidirectional RF links. Frequency hopping techniques increase link reliability and extend operating range. Low standby current requirements (