English
Language : 

W311_05 Datasheet, PDF (17/19 Pages) Cypress Semiconductor – FTG for VIA™ Pro-266 DDR Chipset
W311
REF Clock Output (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
f
Frequency, Actual
Frequency generated by crystal oscillator
tR
Output Rise Edge Rate Measured from 0.4V to 2.4V
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
fST
Frequency Stabilization Assumes full supply voltage reached within 1 ms
from Power-up (cold start) from power-up. Short cycles exist prior to
frequency stabilization.
Zo
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Min.
0.5
0.5
45
–
–
Typ.
14.318
–
–
–
–
40
Max.
2
2
55
3
–
Unit
MHz
V/ns
V/ns
%
ms
Ω
48-MHz Clock Output (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
f
Frequency, Actual
Determined by PLL divider ratio (see m/n below)
fD
Deviation from 48 MHz
(48.008 – 48)/48
m/n
PLL Ratio
(14.31818 MHz x 57/17 = 48.008 MHz)
tR
Output Rise Edge Rate Measured from 0.4V to 2.4V
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
fST
Frequency Stabilization Assumes full supply voltage reached within 1 ms
from Power-up (cold start) from power-up. Short cycles exist prior to
frequency stabilization.
Zo
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Min.
0.5
0.5
45
–
–
Typ.
48.008
+167
57/17
–
–
–
–
40
Max.
2
2
55
3
–
Unit
MHz
ppm
V/ns
V/ns
%
ms
Ω
24-MHz Clock Output (Lump Capacitance Test Load = 20 pF)
Parameter
Description
Test Condition/Comments
f
Frequency, Actual
Determined by PLL divider ratio (see m/n below)
fD
Deviation from 24 MHz
(24.004 – 24)/24
m/n
PLL Ratio
(14.31818 MHz x 57/34 = 24.004 MHz)
tR
Output Rise Edge Rate Measured from 0.4V to 2.4V
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
tD
Duty Cycle
Measured on rising and falling edge at 1.5V
fST
Frequency Stabilization Assumes full supply voltage reached within 1 ms
from Power-up (cold start) from power-up. Short cycles exist prior to
frequency stabilization.
Zo
AC Output Impedance
Average value during switching transition. Used
for determining series termination value.
Min.
0.5
0.5
45
–
–
Typ.
24.004
+167
57/34
–
–
–
–
40
Max.
2
2
55
3
–a
Unit
MHz
ppm
V/ns
V/ns
%
ms
Ω
Ordering Information
Ordering Code
Package Type
W311H
48-pin SSOP
W311HT
48-pin SSOP - Tape and Reel
Lead-free
CYW311OXC
48-pin SSOP
CYW311OXCT
48-pin SSOP - Tape and Reel
Product Flow
Commercial, 0°C to 70°C
Commercial, 0°C to 70°C
Commercial, 0°C to 70°C
Commercial, 0°C to 70°C
Document #: 38-07703 Rev. **
Page 17 of 19