S1K50000 Epson Electronics America, Inc., S1K50000 Datasheet - Page 98

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

STANDARD CELL S1K50000 SERIES
DESIGN GUIDE
b) Overshoot, undershoot, and ringing
Some types of noise, known as overshoot, undershoot, and ringing, are generated by the
equivalent inductance inherent in output pins. This equivalent inductance is represented by
L3 in Figure 8-1. Because inductance tends to accumulate energy, even when the output
changes state to low or high, the accumulated energy generates an overshoot, undershoot,
or ringing. Therefore, overshoot and undershoot are proportionate to the magnitude of
flowing current, and also to the change rate of the current.
The most efficient means of reducing overshoot and undershoot is the use of output cells
with a small drive capability. As the load capacitance increases, overshoot and undershoot
tend to decrease. Therefore, caution is required, particularly when output cells with a large
drive capability are used.
Input pin
V
1
Figure 8-1 Equivalent Circuit of an LSI
L
L
2
1
EPSON
V
Chapter 8: Pin Arrangement and Simultaneous Operation
DD
pin
V
DD
V
SS
(internal)
(internal)
L
3
Output
93