Cypress Semiconductor CY7B992 Arkusz specyfikacji - Strona 8

Przeglądaj online lub pobierz pdf Arkusz specyfikacji dla Sprzęt komputerowy Cypress Semiconductor CY7B992. Cypress Semiconductor CY7B992 20 stron. Cypress programmable skew clock buffer specification sheet

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Switching Characteristics

Parameter
f
Operating Clock
NOM
Frequency in MHz
t
REF Pulse Width HIGH
RPWH
t
REF Pulse Width LOW
RPWL
t
Programmable Skew Unit
U
t
Zero Output Matched-Pair Skew
SKEWPR
[16, 17]
(XQ0, XQ1)
t
Zero Output Skew (All Outputs)
SKEW0
t
Output Skew (Rise-Rise, Fall-Fall, Same
SKEW1
Class Outputs)
t
Output Skew (Rise-Fall, Nominal-Inverted,
SKEW2
Divided-Divided)
t
Output Skew (Rise-Rise, Fall-Fall, Different
SKEW3
Class Outputs)
t
Output Skew (Rise-Fall, Nominal-Divided,
SKEW4
Divided-Inverted)
t
Device-to-Device Skew
DEV
t
Propagation Delay, REF Rise to FB Rise
PD
t
Output Duty Cycle Variation
ODCV
t
Output HIGH Time Deviation from 50%
PWH
t
Output LOW Time Deviation from 50%
PWL
t
Output Rise Time
ORISE
t
Output Fall Time
OFALL
t
PLL Lock Time
LOCK
t
Cycle-to-Cycle Output
JR
Jitter
Notes
12. CMOS output buffer current and power dissipation specified at 50 MHz reference frequency.
13. Test measurement levels for the CY7B991 are TTL levels (1.5V to 1.5V). Test measurement levels for the CY7B992 are CMOS levels (VCC/2 to VCC/2). Test
conditions assume signal transition times of 2 ns or less and output loading as shown in the
14. Guaranteed by statistical correlation. Tested initially and after any design or process changes that affect these parameters.
15. Except as noted, all CY7B992–2 and –5 timing parameters are specified to 80 MHz with a 30 pF load.
16. SKEW is defined as the time between the earliest and the latest output transition among all outputs for which the same tU delay is selected when all are loaded
with 50 pF and terminated with 50Ω to 2.06V (CY7B991) or VCC/2 (CY7B992).
17. tSKEWPR is defined as the skew between a pair of outputs (XQ0 and XQ1) when all eight outputs are selected for 0tU.
18. tSKEW0 is defined as the skew between outputs when they are selected for 0tU. Other outputs are divided or inverted but not shifted.
19. CL=0 pF. For CL=30 pF, tSKEW0=0.35 ns.
20. There are three classes of outputs: Nominal (multiple of tU delay), Inverted (4Q0 and 4Q1 only with 4F0 = 4F1 = HIGH), and Divided (3Qx and 4Qx only in
Divide-by-2 or Divide-by-4 mode).
21. tDEV is the output-to-output skew between any two devices operating under the same conditions (VCC ambient temperature, air flow, and so on.)
22. tODCV is the deviation of the output from a 50% duty cycle. Output pulse width variations are included in tSKEW2 and tSKEW4 specifications.
23. Specified with outputs loaded with 30 pF for the CY7B99X–2 and –5 devices and 50 pF for the CY7B99X–7 devices. Devices are terminated through 50Ω to
2.06V (CY7B991) or VCC/2 (CY7B992).
24. tPWH is measured at 2.0V for the CY7B991 and 0.8 VCC for the CY7B992. tPWL is measured at 0.8V for the CY7B991 and 0.2 VCC for the CY7B992.
25. tORISE and tOFALL measured between 0.8V and 2.0V for the CY7B991 or 0.8VCC and 0.2VCC for the CY7B992.
26. tLOCK is the time that is required before synchronization is achieved. This specification is valid only after VCC is stable and within normal operating limits.
This parameter is measured from the application of a new signal or frequency at REF or FB until tPD is within specified limits.
Document Number: 38-07138 Rev. *B
Over the Operating Range
Description
[1, 2]
FS = LOW
[1, 2]
FS = MID
[1, 2 , 3]
FS = HIGH
[16, 18,19]
[16, 19]
[16, 19]
[16, 19]
[16, 19]
[14, 21]
[22]
[23, 24]
[23, 24]
[23, 25]
[23, 25]
[26]
[14]
RMS
[14]
Peak-to-Peak
[2, 13]
[14]
CY7B991–2
Min
Typ
Max
15
30
25
50
40
80
5.0
5.0
See
0.05
0.20
0.1
0.25
0.25
0.5
0.3
0.5
0.25
0.5
0.5
0.9
0.75
–0.25
0.0
+0.25
–0.65
0.0
+0.65
2.0
1.5
0.15
1.0
1.2
0.15
1.0
1.2
0.5
25
200
AC Test Loads and Waveforms
CY7B991
CY7B992
[14]
CY7B992–2
Min
Typ
Max
Unit
15
30
MHz
25
50
[15]
40
80
5.0
5.0
Table 1
0.05
0.20
0.1
0.25
0.25
0.5
0.3
0.5
0.25
0.5
0.5
0.7
0.75
–0.25
0.0
+0.25
–0.5
0.0
+0.5
3.0
3.0
0.5
2.0
2.5
0.5
2.0
2.5
0.5
ms
25
200
unless otherwise specified.
Page 8 of 19
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