Overview
Description
The IDT728 combines the functions of a VCXO (Voltage Controlled Crystal Oscillator) and PLL (Phase Locked Loop) frequency doubler onto a single chip. Used in conjunction with an external pullable quartz crystal, this monolithic integrated circuit replaces more costly hybrid (canned) VCXO devices. The IDT728 is designed primarily for data and clock recovery applications within end products such as set-top box receivers. The IDT728 exhibits a moderate VCXO gain of 110 ppm/V typical, when used with a high quality external pullable quartz crystal. The frequency of the on-chip VCXO is adjusted by an external control voltage input into pin VIN. Because VIN is a high impedance input, it can be driven directly from an PWM RC integrator circuit. Frequency output increases with VIN voltage input. The usable range of VIN is 0 to 3.3 V.
Features
- Ideal for set-top box applications using 13.5 MHz external pullable crystal to generate lock 27 MHz clock transport video clock
- On-chip VCXO with guaranteed pull range of ±110 ppm minimum
- VCXO input tuning voltage 0 to 3.3 V
- Packaged in 8-pin SOIC (150 mil wide)
- Available in Pb (lead) free package
Comparison
Applications
Design & Development
Models
ECAD Models
Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.