The SSTX4915 is a low power ASK transmitter IC intended for applications in the North American and European VHF/UHF bands. The integrated voltage-controlled oscillator (VCO), phase/frequency detector, prescaler, and reference oscillator require only the addition of an external crystal to provide a complete phase-locked loop (PLL). In addition to the standard power-down mode, the chip also includes an automatic lock-detect feature that disables the transmitter output when the PLL is out-of-lock.