S1K50000 Epson Electronics America, Inc., S1K50000 Datasheet - Page 89

• Manufacturer Part Number: S1K50000
• Description: Design Guide S1k50000 Series
• Manufacturer: Epson Electronics America, Inc.

Chapter 7: Estimating Power Consumption
84
(1) Power consumption in input buffers (P
(2) Power consumption of output buffers (P
The power consumption in input buffers is the sum total of the signal frequencies entered in
each buffer (MHz) multiplied by Kp i (µW/MHz).
The power consumption of output buffers differs between DC loads (resistive loads, such
as when the counterpart to be connected to is a TTL device) and AC loads (capacitive
loads, such as when the counterpart to be connected to is a CMOS device).
In the case of an AC load, the power consumption can be obtained based on the load
capacitance CL in the following manner:
• AC power consumption
P
In the case of a DC load, the power consumption consists of the amount of power
consumed by a DC load plus the AC power consumption.
AC
= f
where f
C
P
where Kp
L
C
V
i
DD
L
=
(V
i=1
K
: operating frequency of the output buffer (Hz)
: load capacitance (F)
: power-supply voltage (V)
Table 7-1 Input Cell Kpi in the S1K50000 Series
DD
f
(Kp
)
i
2
i
V
(W)
i
DD
: power factor of the input buffer (µW/MHz). See Table 7-1
: operating frequency of the
3.3 V
2.0 V
below. Varies with the operating voltage.
f
(Typ.)
i
) (W)
EPSON
i
)
o
)
6.2 µW/MHz
2.0 µW/MHz
Kp
i
’th input buffer (MHz)
i
STANDARD CELL S1K50000 SERIES
DESIGN GUIDE