MPC972 Freescale Semiconductor, Inc, MPC972 Datasheet
MPC972
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MPC972 Summary of contents
Page 1
... LVCMOS levels with the capability to drive 50Ω transmission lines. For series terminated lines each MPC972/973 output can drive two 50Ω lines in parallel thus effectively doubling the fanout of the device. The MPC972/973 can consume significant power in some configurations. Users are encouraged to review Application Note AN1545/D in the Timing Solutions book (BR1333/D) for a discussion on the thermal issues with the MPC family of clock drivers ...
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... MPC972 MPC973 39 38 fselb1 40 fselb0 41 fsela1 42 fsela0 43 Qa3 44 VCCO 45 Qa2 46 GNDO 47 Qa1 48 VCCO 49 Qa0 50 GNDO 51 VCO_Sel FUNCTION TABLE 1 fsela1 fsela0 FUNCTION TABLE 2 fselFB2 fselFB1 fselFB0 ...
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... BR1333 — Rev VCO LPF Sync Pulse Data Generator Output Disable 12 Circuitry Figure 2. Logic Diagram 3 MPC972 MPC973 Sync Qa0 D Q Frz Qa1 Qa2 Qa3 Sync Qb0 D Q Frz Qb1 Qb2 Qb3 Sync Qc0 ...
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... MPC972 MPC973 fVCO Qa Qc Sync Qa Qc Sync Qc( 2) Qa( 6) Sync Qa( 4) Qc( 6) Sync Qc( 2) Qa( 8) Sync Qa( 6) Qc( 8) Sync Qa( 12) Qc( 2) Sync MOTOROLA 1:1 Mode 2:1 Mode 3:1 Mode 3:2 Mode 4:1 Mode 4:3 Mode 6:1 Mode Figure 3. Timing Diagrams 4 TIMING SOLUTIONS BR1333 — Rev 6 ...
Page 5
... V CMR is the difference from the most positive side of the differential input signal. Normal operation is obtained when the “High” input is within the V CMR range and the input lies within the V PP specification. 2. The MPC972/973 outputs can drive series or parallel terminated 50Ω (or 50Ω /2) transmission lines on the incident edge (see Applications Info section). ...
Page 6
... This inversion allows for the development of 180 phase shifted clocks. This output could also be used as a feedback output to the MPC972/973 or a second PLL device to generate early or late clocks for a specific design. Figure 11 illustrates the use of two ...
Page 7
... MPC972/973’s to generate two banks of clocks with one bank divided by 2 and delayed by 180 relative to the first. Using the MPC973 as a Zero Delay Buffer The external feedback of the MPC973 clock driver allows for its use as a zero delay buffer. By using one of the outputs as a feedback to the PLL the propagation delay through the device is eliminated ...
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... MPC972 MPC973 400 300 200 100 0 –100 –200 –300 –400 Qc3 Qc2 Qc1 500 400 Max 300 200 100 Nom 0 –100 Min –200 Reference Clock Frequency (MHz) Figure 5. Static Phase Offset versus Reference Frequency T pd versus TCLK 60 58 ...
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... Qc 66MHz ‘0’ fselFB2 ‘1’ Inv_Clk QFB 66MHz Input Ref Ext_FB Figure 11. Phase Delay Using Multiple MPC972/973’s TIMING SOLUTIONS BR1333 — Rev 6 ‘0’ fsela0 ‘0’ fsela1 100MHz ‘0’ fselb0 fselb1 ‘0’ 40MHz ‘ ...
Page 10
... The on–board oscillator is completely self contained so that the only external component required is the crystal. As the oscillator is somewhat sensitive to loading on its inputs the user is advised to mount the crystal as close to the MPC972 as possible to avoid any board level parasitics. To facilitate co–location surface mount crystals are recommended, but not required ...
Page 11
... VCC/2. This technique draws a fairly high level of DC current and thus only a single terminated line can be driven by each output of the MPC972/973 clock driver. For the series terminated case however there current draw, thus the outputs can drive multiple series terminated lines ...
Page 12
... NRZ freeze enable bits. The period of each Frz_Data bit equals the period of the free–running Frz_Clk signal. The Frz_Data serial transmission should be timed so the MPC972 can sample each Frz_Data bit with the rising edge of the free–running Frz_Clk signal. Start ...
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... 0.10 (0.004) T VIEW θ1 0.25 (0.010) θ GAGE PLANE MPC972 MPC973 –X– X= VIEW Y BASE METAL F PLATING É É É É Ç Ç Ç Ç É É É É Ç Ç Ç Ç D 0.13 (0.005) T L– ...
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... MPC972 MPC973 Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “ ...