W149_02 Datasheet, PDF (11/16 Pages) Cypress Semiconductor – 440BX AGPset Spread Spectrum Frequency Synthesizer

W149
AC Electrical Characteristics
T_A = 0°C to +70°C; V_DDQ3 = 3.3V±5%; V_DDQ2 = 2.5V±5%; f_XTL = 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, CPU_F, CPU1 (Lump Capacitance Test Load = 20 pF)
CPU = 66.6 MHz CPU = 100 MHz
Parameter
Description
Test Condition/Comments
Min. Typ. Max. Min. Typ. Max. Unit
t_P
Period
t_H
High Time
Measured on rising edge at 1.25V
15
Duration of clock cycle above 2.4V, at 5.6
min. edge rate (1.5 V/ns)
15.5 10
3.3
10.5 ns
ns
t_L
Low Time
Duration of clock cycle below 0.4V, at 5.3
3.1
ns
min. edge rate (1.5 V/ns)
t_R
Output Rise Edge Rate Measured from 0.4V to 2.4V
1.5
4 1.5
4 V/ns
t_F
Output Fall Edge Rate Measured from 2.4V to 0.4V
1.5
4 1.5
4 V/ns
t_D
Duty Cycle
Measured on rising and falling edge at 45
1.5V, at min. edge rate (1.5 V/ns)
55 45
55 %
t_JC
Jitter, Cycle-to-Cycle Measured on rising edge at 1.25V. Max-
250
imum difference of cycle time between
two adjacent cycles.
250 ps
t_SK
Output Skew
Measured on rising edge at 1.5V
175
f_ST
Frequency Stabiliza- Assumes full supply voltage reached
3
tion from Power-up within 1 ms from power-up. Short cycles
(cold start)
exist prior to frequency stabilization.
175 ps
3 ms
Z_o
AC Output Impedance Average value during switching transi-
20
tion. Used for determining series termi-
nation value.
20
Ω
Document #: 38-07176 Rev. *A
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