W144
DC Electrical Characteristics TA = 0°C to +70°C; VDDQ3 = 3.3V 5ꢀ; VDDQ2 = 2.5V 5ꢀ (continued)
Parameter
Description
Test Condition
Min.
Typ.
Max.
Unit
Crystal Oscillator
VTH
X1 Input threshold Voltage[6]
VDDQ3 = 3.3V
–
–
1.65
14
–
–
V
CLOAD
Load Capacitance, Imposed on
External Crystal[7]
pF
CIN,X1
X1 Input Capacitance[8]
Pin X2 unconnected
Except X1 and X2
–
28
–
pF
Pin Capacitance/Inductance
CIN Input Pin Capacitance
COUT
LIN
–
–
–
–
–
–
5
6
7
pF
pF
nH
Output Pin Capacitance
Input Pin Inductance
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.
AC Electrical Characteristics
TA = 0°C to +70°C; VDDQ3 = 3.3V 5%; VDDQ2 = 2.5V 5%;
f
XTL = 14.31818 MHz
CPU Clock Outputs, CPU_F, CPU1 (Lump Capacitance Test Load = 20 pF)
CPU = 66.6 MHz CPU = 100.2 MHz
Parameter
tP
Description
Period
Test Condition/Comments
Measured on rising edge at 1.25
Duration of clock cycle above 2.0V
Duration of clock cycle below 0.4V
Min. Typ. Max. Min. Typ. Max. Unit
15
5.6
5.3
1.5
1.5
–
–
–
–
–
–
15.5 9.98
–
–
–
–
–
–
10.5
–
ns
ns
tH
tL
High Time
Low Time
–
–
3.3
3.1
1.5
1.5
45
–
ns
tR
tF
tD
Output Rise Edge Rate Measured from 0.4V to 2.0V
Output Fall Edge Rate Measured from 2.0V to 0.4V
4
4
V/ns
V/ns
ꢀ
4
4
Duty Cycle
Measured on rising and falling edge at 45
1.25V
55
55
tJC
Jitter, Cycle-to-Cycle
Measured on rising edge at 1.25V.
Maximum difference of cycle time
between two adjacent cycles.
–
–
200
–
–
200
ps
tSK
fST
Output Skew
Measured on rising edge at 1.25V
–
–
–
–
250
3
250
3
ps
Frequency Stabilization Assumes full supply voltage reached
within 1 ms from power-up. Short cycles
exist prior to frequency stabilization.
–
–
–
ms
from Power-up (cold
start)
Zo
AC Output Impedance Average value during switching
transition. Used for determining series
termination value.
–
20
–
20
–
:
Notes:
6. X1 input threshold voltage (typical) is V
/2.
DDQ3
7. The W144 contains an internal crystal load capacitor between pin X1 and ground and another between pin X2 and ground. Total load placed on crystal is 14 pF;
this includes typical stray capacitance of short PCB traces to crystal.
8. X1 input capacitance is applicable when driving X1 with an external clock source (X2 is left unconnected).
Rev 1.0,November 21, 2006
Page 10 of 13
SPECTRALINEAR [ SPECTRALINEAR INC ]
