Logic Design for ArrayBased Circuitsby Donnamaie E. WhiteCopyright © 1996, 2001, 2002 Donnamaie E. White 


Power ConsiderationsLast Edit July 22, 2001 Step 7: Compute the WorstCase Overhead CurrentMultiply both the IEE and ICC overhead currents by the worstcase current multiplier for the overhead current (WCCM3) to obtain the worstcase overhead currents
IoverheadEEwc = WCCM3 * IoverheadEE Step 8: Sum the ICC and IEE CurrentsSum the internal macro, interface macro, and overhead worstcase currents, keeping ICC and IEE separate to find the total IEE and ICC worstcase currents
IEEwc = SUM IinternalEEwc + IinterfaceEEwc + IoverheadEEwc Step 9: Multiply by the WorstCase VoltageThe worstcase voltage is dependent on whether the circuit is commercial or military and the specified allowed power supply variations. The array data sheet carries this information. The typical variation is shown below. For commercial circuits, with a 5.2V or a +5V supply, the voltage variation is usually ±5%. For commercial circuits using VEE = 4.5V, the variation is ±7%
For military circuits, the voltage variation is usually ±10%. Note: The worstcase voltage for the 4.5V supply as listed on the Q20000 data sheet, where 4.5V supply varies ±7%. The worstcase voltage is taken as 4.8V for military or commercial circuits
Table 714 Example WorstCase Voltages
Multiply the worstcase DC current by the appropriate worstcase voltage:
PCCDC = ICCwc * VCCwc This product is the worstcase DC power due to the macros on the array. 

Copyright @ 2001,
2002 Donnamaie E. White, White
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