A 5.0mW 0dBm FSK transmitter for 315/433 MHz ISM applications in 0.25 /spl mu/m CMOS

An ultra-low power multi-channel narrowband FSK transmitter has been developed that operates in the 315/433 MHz bands for ISM applications and consumes only 5.0 mW at 1.3 V for an output power of 0 dBm. For an output power of -10 dBm the combination of the minimum power supply (0.9 V) and maximal data rate (100 kbps) leads to an energy consumption of less than 17 nJ/bit. The transmitter has a direct PLL modulation architecture using a /spl Delta//spl Sigma/ fractional-N synthesizer. The IC is implemented in a 0.25 /spl mu/m CMOS process and occupies 4.8 mm/sup 2/.