dp83241 National Semiconductor Corporation, dp83241 Datasheet
dp83241
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dp83241 Summary of contents
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... DP83241 CDD TM Device (FDDI Clock Distribution Device) General Description The CDD device is a clock generation and distribution de- vice intended for use in FDDI (Fiber Distributed Data Inter- face) networks The device provides the complete set of clocks required to convert byte wide data to serial format for ...
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FDDI CHIP SET OVERVIEW 2 0 FUNCTIONAL DESCRIPTION 3 0 PIN DESCRIPTIONS 4 0 ELECTRICAL CHARACTERISTICS 4 1 Absolute Maximum Ratings 4 2 Recommended Operating Conditions Electrical Characteristics Electrical Characteristics Table of ...
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... PHY Layer loopback test Crystal controlled Clock locks in less than 85 ms DP83241 CDD Device TM Clock Distribution Device From MHz reference the Clock Distribution Device synthesizes the 125 MHz 25 MHz and 12 5 MHz clocks required by the BSI BMAC and PLAYER devices ...
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... The external VCO option does provide a means of using these conventional LC oscil- lator techniques if desired Connection Diagram 28-Pin PLCC Package Order Number DP83241BV See NS Package Number V28A FIGURE 2-1 DP83241 Pinout FIGURE 2-2 DP83241 Block Diagram 10385 – 10385 – 3 ...
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Pin Descriptions Pin Symbol Digital V Positive power supply for all the internal circuitry intended for operation GND A bypass capacitor should be placed as close as possible ...
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Pin Descriptions (Continued) Pin Symbol VCO RST 11 I VCO Reset TTL compatible input used to reset the internal VCO on system power up This input stops the VCO from oscillating when at a logic ...
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Electrical Characteristics 4 1 ABSOLUTE MAXIMUM RATINGS If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications b Storage Temperature TTL Signals b Inputs b Outputs ...
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Electrical Characteristics ELECTRICAL CHARACTERISTICS Symbol Parameter T1 TBC to TXC T2 TBC to LBC1 T LBC1 to LBC2 Phase1 T LBC1 to LBC3 Phase2 T LBC1 to LBC4 Phase3 T LBC1 to LBC5 Phase4 T3 ...
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Electrical Characteristics ELECTRICAL CHARACTERISTICS (Continued) FIGURE 4-2 Typical Clock Relationships (Continued 10385 – 5 ...
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... VCO gain K p bandwidth W and the phase margin w The constants K o and K for the DP83241 are fixed rad and Grad V respectively N is equal to the VCO frequency divid the reference frequency w is recommended less than 1 20th of the reference frequency (times 2 ...
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Detailed Information 5 1 EXTERNAL COMPONENTS The Filter components are based MHz Crystal and a 250 MHz VCO All component values g 10% The Filter components are based MHz Crystal ...
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Detailed Information (Continued) TABLE 5-1 Special External Components Crystal Resonator Varactor Diode VHF NPN Transistor Inductor 5 2 CONCENTRATOR AND DUAL ATTACH STATION CONFIGURATIONS Concentrator Applications An application where many of the features of the ...
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Detailed Information (Continued) FIGURE 5-4 Large Concentrator Application e T Time to latch data out of the Physical Layer (Board Data flight time Latch delay Ideal setup time ...
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... CDD Device Driving Multiple PLAYER Devices In a FDDI concentrator or dual attach station it may be necessary for a single DP83241 Clock Distribution Device (CDD device) to drive multiple DP83251 55 PLAYER devic- es Since these PLAYER devices will be running synchro- nously to each other they must have the same clocks The ...
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... Traces longer then one inch should have a series or parallel termination scheme Further sys- tem considerations can be found in National’s F100K De- sign Guide If these methods are followed the DP83241 sig- nals will be able to drive multiple DP83251 55 PLAYER de- vices without any problems 10385 – ...
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Detailed Information (Continued LAYOUT RECOMMENDATIONS The part should be bypassed between the EXTV EXTGND as close to the chip as possible (preferably un- der the chip using chip caps) The part should also be bypassed ...
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Detailed Information (Continued INPUT AND OUTPUT SCHEMATICS XVCO IN XVCO INB Filter CMOS Inputs REF IN FEEDBK IN PHASE SEL VCO RST VCO SEL XTL IN XTL OUT TL F 10385 – 16 TTL Outputs LBC1 ...
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Detailed Information (Continued SYSTEM DEBUGGING FLOWCHART Note 1 If the crystal oscillator is chosen as the input reference source then the XTL OUT pin should be checked for the correct frequency of oscillation If the oscillator ...
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... National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications Plastic Chip Carrier (V) Order Number DP83241BV NS Package Number V28A 2 A critical component is any component of a life ...