Offered as replacements for more costly voltage-controlled oscillator (VCXO) modules, these three new crystal oscillator clock chips operate from a 3.3V power supply and span a 10 MHz to 40 MHz frequency range. The PI6CX100-27 and PI6CX100-35 are 27 MHz and 35 MHz clock circuits, respectively, while the PI6CX-101, a generic device, operates from 10 MHz to 40 MHz.Specs common to all three devices include a VCXO tuning voltage range from 0V to 3.3V, an on-chip VCXO with a pull range of 240 ppm, and an output drive of 10 mA at CMOS levels. The clock circuits require an inexpensive, external crystal. Price: $2.65 each/1,000. PERICOM SEMICONDUCTOR CORP., San Jose, CA. (800) 435-2336.