High output power PLL UHF ASK/FSK transmitter device developed for low-cost RF transmission systems at data rates up to 32 kBaud. The device features high output power (5.5 dBm) with low supply current (8.5 mA). The transmitting frequency range is 310MHz to 330MHz. FSK modulation is achieved by connecting an additional capacitor between the XTAL load capacitor and the open drain output of the modulating microcontroller. The devices suppots a supply voltage 2.0V to 4.0V in the temperature range of -40°C to +85°C/+125??C, ideal for tire pressure monitoring (TPM) applications.