特長
- Two differential LVDS outputs (Bank A), configurable for PCIe (100MHz or 250MHz) and sRIO (100MHz or 125MHz) clock signals
- Eight LVCMOS/LVTTL outputs (Bank B/C), 18Ω typical output impedance
- Two REF_OUT LVCMOS/LVTTL clock outputs 23Ω typical output impedance
- Selectable crystal oscillator interface, 25MHz, 18pF parallel resonant crystal or one LVCMOS/LVTTL single-ended reference clock input
- Supports the following output frequencies: LVDS Bank A: 100MHz, 125MHz, 200MHz and 250MHz LVCMOS/LVTTL Bank B/C: 33.33MHz, 50MHz, 66.67MHz, 100MHz, 125MHz, 133.33MHz, 166.67MHz and 200MHz
- VCO: 2GHz
- Spread spectrum clock: ±0.25% center-spread, and -0.6% down-spread
- PLL bypass and output enable
- RMS period jitter: 23ps (maximum), QB outputs
- Full 3.3V supply voltage
- -40°C to 85°C ambient operating temperature
- Available in a lead-free (RoHS 6) compliant package
説明
The 844S012I-01 is an optimized PCIe, sRIO and Gigabit Ethernet Frequency Synthesizer. The 844S012I-01 uses a 25MHz parallel resonant crystal to generate 33.33MHz - 200MHz clock signals, replacing solutions requiring multiple oscillator and fanout buffer solution. The device supports ±0.25% center-spread, and -0.6% down-spread clocking with two spread select pins (SSC[1:0]). The VCO operates at frequency of 2GHz. The device has three output banks: Bank A with two LVDS outputs, 100MHz – 250MHz; Bank B with seven 33.33MHz – 200MHz LVCMOS/ LVTTL outputs; and Bank C with one 33.33MHz – 200MHz LVCMOS/LVTTL output.
All Banks A, B and C have their own dedicated frequency select pins and can be independently set for the frequencies mentioned above. The low jitter characteristic of the 844S012I-01 makes it an ideal clock source for PCIe, sRIO and Gigabit Ethernet applications. Designed for networking and industrial applications, the 844S012I-01 can also drive the high-speed clock inputs of communication processors, DSPs, switches and bridges. The 843241I-04 is a Serial ATA (SATA)/Serial Attached SCSI (SAS) Clock Generator and a member of the HiPerClocksTM family of high performance devices from IDT. For SATA/SAS applications, a 25MHz crystal is used to produce 150MHz. The 843241I-04 is packaged in a small 8-pin TSSOP, making it ideal for use in systems with limited board space.
