Intel 80386

PHYSICAL DESIGN AND DEBUGGING
160r----..-----------------------------,
140
120
r:f 100
80~--------------~---------------
60
DO NOT USE < 80 pF
10 20
30
40
TERMINATION RESISTOR (OHMS)
•
CL = CIN (386) + CIN (387) + CIN (PALs) + ... + CBOARD.
CBOARD IS CALCULATED FROM LAYOUT AND BOARD PARAMETERS:
THICKNESS, DIELECTRIC CONSTANT, DISTANCE TO GROUNDIVcc PLANES .
• TERMINATION RESISTOR MUST BE LOW INDUCTANCE TYPE.
RECOMMEND CARBON FILLED TYPE.
G30107
Figure 11-8. CLK2 Series Termination
where
T
j
= junction temperature
a
ambient temperature
Tc = case tempterature
Oja = junction-to-ambient temperature coefficient
Ojc = junction-to-case temperature coefficient
PD = power dissipation (worst-case Icc * Vee
11-8