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PRODUCT SPECIFICATION
RC7108
11
Notes:
1. RC7108 logic inputs have internal pull-up resistors.
2. All clock outputs loaded with maximum lump capacitance test load specified in AC Electrical Characteristics section.
3. X1 input threshold voltage (typical) is VDD/2
4. The RC7108 contains an internal crystal load capacitor between X1 and VSS and another between X2 and VSS. The total
load placed on the crystal is 18pF; this includes typical stray capacitance of short PCB traces to the crystal.
5. X1 input capacitance is applicable when X1 is driven with an external clock source (X2 is left unconnected).
AC Electrical Characteristics
T
A
=0
°
C to 70
°
C; VDD=3.3V
±
5%; VDDL=2.5V
±
5%; f
XTL
=14.31818MHz
AC clock parameters are tested and guaranteed over stated operating conditions using the stated lump capacitive load at the
clock output; Spread Spectrum clocking is disabled.
CPU Clock Outputs, CPU0:1 (C
LOAD
=20pF)
I
OH
Output High Current
CPU
IOAPIC
PCI, 3V66
REF, 24MHz,48MHz
SDRAM
Crystal oscillator
V
TH
C
LOAD
Load Capacitance, as seen by
external Xtal.
4
C
IN
Pin Capacitance/Inductance
C
IN
Input Pin Capacitance
C
OUT
Output Pin Capacitance
L
IN
Input Pin Inductance
V
OH
=1.2V
-26
-101
mA
-39
-31
-27
-68
-150
-189
-94
-188
V
OH
=1.4V
X1 Input Threshold Voltage
3
VDD=3.3V
1.5
18
V
pF
X1 Input Capacitance
5
X2 unconnected
28
pF
Except X1 and X2
5
6
7
PF
pF
NH
Parameter
t
P
t
H
t
L
t
R
t
F
t
D
t
JC
t
SK
f
ST
CPU=133MHz
Min.
Typ.
7.5
Units
nS
nS
nS
nS
nS
%
pS
pS
mS
Test Condition/Comments
Meas. at rising edge at 1.25V.
Duration of clock cycle above 2V.
Duration of clock cycle below 0.4V
0.4V to 2.0V
2.0V to 0.4V
Measured at 1.25V
Measured on rising edge at 1.25V.
Measured on rising edge at 1.25V.
Assumes full supply voltage reached within 1mS
from power-up. Short cycles exist prior to
frequency stabilization.
Average value during switching transition. Used
for determining series termination value.
Max.
8
Period
High Time
Low Time
Output Rise Time
Output Fall Time
Duty Cycle
Jitter, Cycle to Cycle
Output Skew
Frequency Stabilization
from Power-up (cold
start)
AC output Impedance
2
1.8
.4
.4
45
1.6
1.6
55
250
175
3
Z
O
20
DC Electrical Characteristics
(Continued)
T
A
= 0
°
C to +70
°
C; VDD = 3.3V
±
5%; VDDL = 2.5V
±
5%
Parameter
Test Condition
Min.
Typ.
Max.
Units