Adjustable Clock Generator between 15.5 MHz and 17.4 MHz
Try looking up Analog Devices range of direct digital synthesizers. Here's one: -



Picture taken from here.

Features and Benefits


Programmable frequency profile—no external components necessary 
Output frequency up to 25 Mhz
Predefined frequency profile minimizes number of DSP/µcontroller writes
Sinusoidal/triangular/square wave outputs
Powerdown mode (20 µA) +2.3 V to +5.5 V power supply
Extended temperature range −40°C to +125°C
16-pin TSSOP