S1X70000 Datasheet, PDF (196/379 Pages) Epson Company – STANDARD CELL / EMBEDDED ARRAY

Chapter 6 Estimating Various Characteristic Values
First calculate the power consumption in the HVDD block of the circuit.
In the example circuit used here, the power consumption in the HVDD block consists
entirely of the power consumed by the I/O cells. First, we’ll calculate the power
consumption of the input buffers.
From Table 6-2, Kpi = 2.57 [µW/MHz] when HVDD = 3.3 V. Therefore,
P_i = 2.57 [µW/MHz] x 66 [MHz] x (30 + 20)
= 8481 [µW]
= 8.481 [mW] .................. (1)
Next, calculate the power consumption of the output buffers.
Because all of the circuit is connected to CMOS Interface, calculate the approximate
amount of power consumption in terms of AC power consumption (PAC).
P_o = 33 x 10⁶ [Hz] x 15 x 10^-12 [F] x 3.3² x (40 x 0.5) + 33 x 10⁶ [Hz] x 15 x 10^-12 [F]
x 3.3² x 20
= 0.2156 [W]
= 215.6 [mW] ................... (2)
Therefore, the approximate amount of power consumption in the HVDD block of the circuit,
P(HVDD), is
P(HVDD) = Pi + Po = (1) + (2)
= 8.481 + 215.6
= 224.081
≅ 224 [mW] ..................... (I)
Next, calculate the approximate amount of power consumption in the LVDD block of the
circuit, P(LVDD), by following the procedure described below.
(1) Power consumption of the Cell-Based area
Because the 300k-gate area and 340k-gate area operate at 66 MHz and 50 MHz,
respectively, and because their circuit operation rates are 30%, the power
consumption of the Cell-Based area to be obtained, PCB, is expressed by the equation
below. (For the Standard-1 Cell-Based part, K_pint = 0.054 [µW/MHz/BC])
PCB =
K
∑
(Nb x fi x Spi x K_pint)
[µW]
i =1
= (300000 x 66 x 0.3 x 0.054) + (340000 x 50 x 0.3 x 0.054) [µW]
= 320.67 [mW] + 275.4 [mW]
= 596.16 [mW] ................... (1)
(2) Power Consumption of Basic Cell-Type 2-Port RAM
From Table 5-111 in Chapter 5, “Power Consumption of RAM,” the power
consumption of 2-port RAM is
151.79 [µW/MHz] for 256 words x 16 bits
70.79 [µW/MHz] for 128 words x 8 bits
Therefore, the power consumption of RAM, PBM, is obtained by the equation below.
PBM = 151.79 x 66 x 4 + 70.79 x 66 x 6 [µW]
= 40.07 [mW] = 28.03 [mW]
= 68.1 [mW]
188
EPSON
STANDARD CELL S1K70000 SERIES
EMBEDDED ARRAY S1X70000 SERIES