Hot-selling and scarce 844S42BKILF Dual Output RF Frequency Synthesizer VFQFN spot stock

Product Descriptions

The 844S42I is a 3.3V compatible, PLL based clock synthesizer  targeted for clock generation in high-performance instrumentation,  networking and computing applications. Using either the serial (I2C)  or parallel programming interface, the 844S42I enables the  generation of clock frequencies in the range of 81MHz to 2592MHz.  The internal crystal oscillator uses the external quartz crystal as the  basis of its frequency reference. Alternatively, a LVCMOS compatible  clock signal can be used as PLL reference signal. The devices uses  an integer-N synthesizer architecture and is optimized for low-jitter  generation. The VCO within the PLL operates over a range of  1296MHz to 2592MHz. Its output is scaled by a divider that is  configured by either the I2C or parallel interfaces. The crystal  oscillator frequency fXTAL, the PLL pre-divider P, the feedback-divider  M and the PLL post-divider N determine the output frequency. The  feedback path of the PLL is internal.

The PLL post-dividers NA and NB are configured through either the  I 2C or the parallel interfaces, each can provide one of seven division  ratios (1, 2, 3, 4, 6, 8, 16). This divider extends the performance of  the part while providing a typical 50% duty cycle. The high-frequency  outputs QA and QB are differential and are capable of driving a pair  of transmission lines. The positive supply voltage for the internal PLL  is separated from the power supply for the core logic and output  drivers to minimize noise induced jitter. The serial interface is I2C  compatible and provides read and write access to the internal PLL  configuration registers. The lock state of the PLL is indicated by the  LVCMOS-compatible LOCK_DT output. The 844S42I is packaged  in a 8mm x 8mm 56-lead VFQFN package.

Product Features

• Programmable frequency synthesis optimized for instrumentation, networking and computing applications

• 81MHz to 2592MHz synthesized clock output signal

• Two differential, universal LVDS or LVPECL compatible high-frequency outputs

• Output frequency programmable through 2-wire I2C bus or parallel interface

• On-chip crystal oscillator for reference frequency generation

• Alternative LVCMOS/LVTTL compatible reference clock input

• Clock stop and output enable functionality

• PLL lock indicator output (LVCMOS/LVTTL)

• LVCMOS/LVTTL compatible control inputs

• Fully integrated PLL

• SiGe Technology

• Full 3.3V supply voltage

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

• Available in a lead-free (RoHS 6) compliant package

Product Specification

Product Photos

For more product information, please download the PDF