GENERAL DESCRIPTION

The 841S012DI is an optimized PCIe, sRIO and Gigabit Ethernet

Frequency Synthesizer and a member of high performance clock

solutions from IDT. The 841S012DI uses a 25MHz parallel resonant

crystal to generate 33.33MHz - 200MHz clock signals, replacing

multiple oscillators and fanout buffer solutions. The device supports

±0.25 center-spread, and -0.5 down-spread clocking with two

spread select pins (SSC[1:0]). The VCO operates at a frequency of

2GHz. The device has three output banks: Bank A with two 100MHz

– 250MHz HCSL outputs; 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 841S012DI

makes it an ideal clock source for PCIe, sRIO and Gigabit Ethernet

applications. Designed for networking and industrial applications,

the 841S012DI can also drive the high-speed clock inputs of communication processors, DSPs, switches and bridges.

FEATURES

• Two 0.7V differential HCSL outputs (Bank A), confi gurable for

PCIe (100MHz or 250MHz) and sRIO (100MHz or 125MHz)

clock signals

Eight LVCMOS/LVTTL outputs (Banks 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:

HCSL 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 (typical) and

-0.6 down-spread (typical)

• PLL bypass and output enable

• RMS period jitter: 10ps (typical), QAx/nQAx outputs

• Full 3.3V supply mode

• -40°C to 85°C ambient operating temperature

• Available in lead-free (RoHS 6) package