W159 Datasheet, PDF (7/11 Pages) Cypress Semiconductor – Spread Spectrum System FTG for SMP Systems

W159
3V33 Clock Outputs, 3V33_0:1 (Lump Capacitance Test Load = 30 pF)
Parameter
Description
t_P
Period
t_H
High Time
t_L
Low Time
t_R
Output Rise Edge Rate
t_F
Output Fall Edge Rate
t_D
Duty Cycle
t_JC
Jitter, Cycle-to-Cycle
Test Condition/Comments
Measured on rising edge at 1.5V^[19]
Duration of clock cycle above 2.4V
Duration of clock cycle below 0.4V
Measured from 0.4V to 2.4V
Measured from 2.4V to 0.4V
Measured on rising and falling edge at 1.5V
Measured on rising edge at 1.5V. Maximum difference of
cycle time between two adjacent cycles.
Min. Typ. Max. Unit
30
ns
12
ns
12
ns
1
4 V/ns
1
4 V/ns
45
55 %
500 ps
t_SK
Output Skew
Measured on rising edge at 1.5V
500 ps
t_O
3V66 to 3V33 Clock Covers all 3V66 outputs. Measured on rising edge at 1.5V. 1.5
3.0 ns
Skew
3V66 leads 3V33 output.
t_q
CPU to 3V33 Clock
Covers all 3V33 outputs. Measured on rising edge at 1.5V. 1.5
4.0 ns
Skew
CPU leads 3V33 output.
f_ST
Frequency Stabilization Assumes full supply voltage reached within 1 ms from
from Power-up (cold power-up. Short cycles exist prior to frequency stabilization.
start)
3 ms
Z_o
AC Output Impedance Average value during switching transition. Used for deter-
15
Ω
mining series termination value.
REF Clock Outputs, REF0:1 (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
f
Frequency, Actual
Frequency generated by crystal oscillator
t_R
Output Rise Edge Rate
Measured from 0.4V to 2.4V
t_F
Output Fall Edge Rate
Measured from 2.4V to 0.4V
t_D
Duty Cycle
Measured on rising and falling edge at 1.5V
f_ST
Frequency Stabilization from Assumes full supply voltage reached within
Power-up (cold start)
1 ms from power-up. Short cycles exist prior to
frequency stabilization.
Z_o
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Note:
19. 3V33 clock is CPU/4 for CPU = 133 MHz and CPU/3 for CPU = 100 MHz.
Min.
0.5
0.5
45
Typ.
14.318
25
Max.
2
2
55
3
Unit
MHz
V/ns
V/ns
%
ms
Ω
Document #: 38-07163 Rev. *A
Page 7 of 11