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W164 Datasheet, PDF (9/11 Pages) Cypress Semiconductor – Spread Spectrum Desktop/Notebook System Frequency Generator
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W164
DC Electrical Characteristics: TA = 0°C to +70°C, VDDQ3 = 3.3V±5%, VDDQ2 = 2.5V±5% (continued)
Parameter
Description
Test Condition
Min.
Typ.
Max.
Unit
Crystal Oscillator
VTH
X1 Input Threshold Voltage[6]
CLOAD
Load Capacitance, as seen by
External Crystal[7]
CIN,X1
X1 Input Capacitance[8]
Pin Capacitance/Inductance
VDDQ3 = 3.3V
Pin X2 unconnected
1.65
V
13
pF
26
pF
CIN
COUT
LIN
Input Pin Capacitance
Output Pin Capacitance
Input Pin Inductance
Except X1 and X2
pF
pF
7
nH
AC Electrical Characteristics
TA = 0°C to +70°C, VDDQ3 = 3.3V±5%,VDDQ2 = 2.5V± 5%, fXTL = 14.31818 MHz
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 (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
tP
Period
Measured on rising edge at 1.25V
tH
High Time
Duration of clock cycle above 2.0V
tL
Low Time
Duration of clock cycle below 0.4V
tR
Output Rise Edge Rate Measured from 0.4V to 2.0V
tF
Output Fall Edge Rate Measured from 2.0V to 0.4V
tD
Duty Cycle
Measured on rising and falling edge at
1.25V
tJC
Jitter, Cycle-to-Cycle Measured on rising edge at 1.25V.
Maximum difference of cycle time
between two adjacent cycles.
tSK
Output Skew
Measured on rising edge at 1.25V
fST
Frequency Stabili-
Assumes full supply voltage reached
zation from Power-up within 1 ms from power-up. Short cycles
(cold start)
exist prior to frequency stabilization.
Zo
AC Output Impedance Average value during switching
transition. Used for determining series
termination value.
CPU = 66.8 MHz
Min. Typ. Max.
15
15.5
5.2
5.0
1
4
1
4
45
55
200
175
3
20
CPU = 100 MHz
Min. Typ. Max.
10
10.5
3.0
2.8
1
4
1
4
45
55
250
175
3
20
Unit
ns
ns
ns
V/ns
V/ns
%
ps
ps
ms
:
Notes:
6. X1 input threshold voltage (typical) is VDD/2.
7. The W164 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 28, 2006
Page 9 of 11
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