S1X70000 Datasheet, PDF (311/379 Pages) Epson Company – STANDARD CELL / EMBEDDED ARRAY

Chapter 7 Circuit Design
Note 1: For the power-supply pins HVDD, LVDD, and VSS, there must be at least
four pairs of power-supply pins, that is, one pair on each side of the LSI.
IDD represents a value equal to the power consumption obtained in
Chapter 6, Section 6.1, “Calculation of Power Consumption,” divided by
the operating voltage.
2: If output buffers have DC loads connected to them with current steadily
flowing, power-supply pins must be added. For more information,
contact the sales division of Epson.
3: If it is necessary to add a power supply due to simultaneous changes in
output, add the HVDD, LVDD, and VSS pins for each power-supply system,
separately for the HVDD output buffers and the LVDD output buffers.
Calculation example: The following shows an example of the procedure for estimating the
number of power-supply pins.
Here, the number of power-supply pins is estimated using the power consumption
obtained in Chapter 6 for an IC, which has the following power-supply characteristics.
• Power-supply voltage: HV_DD/LV_DD = 3.3 V/1.8 V
• Power consumption: P(HV_DD) = 224 [mW]
P(LVDD) = 684 [mW]
(1) Estimating the number of HVDD power-supply pins
Letting the number of HVDD power-supply pins be NIDD (HVDD), then
NIDD(HVDD) = 224 [mW] / 3.3 [V] / 30 [mA]
= 2.26 [pins]
Because there must be at least one power-supply pin on each side of the IC, the
number of HVDD power-supply pins to be inserted is 4.
(2) Estimating the number of LVDD power-supply pins
Letting the number of LVDD power-supply pins be NIDD (LVDD), then
NIDD (LVDD) = 684 [mW] / 1.8 [V] / 30 [mA]
= 12.67 [pins]
Therefore, the number of LVDD power-supply pins to be inserted is 13.
(3) Estimating the number of VSS power-supply pins
Letting the number of VSS power-supply pins be NIDD (VSS), then
NIDD (VSS) = {224 [mW] / 3.3 [V] + 684 [mW] / 1.8 [V] } / 30 [mA]
= 14.93 [pins]
Therefore, the number of VSS power-supply pins to be inserted is 15 (however, we
recommend that VSS pins be placed in pairs with the HVDD and LVDD power-supply
pins).
Thus, the respective numbers of power-supply pins are as follows.
HVDD power-supply pins : 4
LVDD power-supply pins : 13
VSS power-supply pins : 15
STANDARD CELL S1K70000 SERIES
EMBEDDED ARRAY S1X70000 SERIES
EPSON
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