Overview
Description
The 8761I is a low voltage, low skew PCI / PCI-X clock generator. The 8761I has a selectable REF_CLK or crystal input. The REF_CLK input accepts LVCMOS or LVTTL input levels. The 8761I has a fully integrated PLL along with frequency configurable clock and feedback outputs for multiplying and regenerating clocks with "zero delay". Using a 20MHz or 25MHz crystal or a 33.333MHz or 66.666MHz reference frequency, the 8761I will generate output frequencies of 33.333MHz, 66.666MHz, 100MHz and 133.333MHz simultaneously. The low impedance LVCMOS/LVTTL outputs of the 8761I are designed to drive 50Ω series or parallel terminated transmission lines.
Features
- Fully integrated PLL
- Seventeen LVCMOS/LVTTL outputs, 15Ω typical output impedance
- Selectable crystal oscillator interface or LVCMOS/LVTTL REF_CLK
- Maximum output frequency: 166.67MHz
- Maximum crystal input frequency: 40MHz
- Maximum REF_CLK input frequency: 83.33MHz
- Individual banks with selectable output dividers for generating 33.333MHz, 66.66MHz, 100MHz and 133.333MHz simultaneously
- Separate feedback control for generating PCI / PCI-X frequencies from a 20MHz or 25MHz crystal or 33.333MHz or 66.666MHz reference frequency
- Cycle-to-cycle jitter: 70ps (maximum)
- Period jitter, RMS: 17ps (maximum)
- Output skew: 250ps (maximum)
- Bank skew: 50ps (maximum)
- Static phase offset: 0 ± 150ps (maximum)
- Full 3.3V or 3.3V core, 2.5V multiple output supply modes
- -40°C to 85°C ambient operating temperature
- Available in lead-free RoHS-compliant 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.