EBE41EF8ABFA
Clock Jitter [DDR2-800, 667]
-8G
-6E
Frequency (Mbps)
Parameter
800
667
Symbol
min.
2500
−100
max.
8000
100
min.
3000
−125
max.
8000
125
Unit
ps
Notes
Average clock period
Clock period jitter
tCK (avg)
tJIT (per)
1
5
ps
Clock period jitter during
DLL locking period
tJIT
(per, lck)
−80
80
−100
100
250
200
ps
ps
ps
5
6
6
Cycle to cycle period jitter
tJIT (cc)
200
160
Cycle to cycle clock period jitter
during DLL locking period
tJIT (cc, lck)
Cumulative error across 2 cycles
Cumulative error across 3 cycles
Cumulative error across 4 cycles
Cumulative error across 5 cycles
tERR (2per) −150
tERR (3per) −175
tERR (4per) −200
tERR (5per) −200
150
175
200
200
−175
−225
−250
−250
175
225
250
250
ps
ps
ps
ps
7
7
7
7
Cumulative error across
n=6,7,8,9,10 cycles
tERR
(6-10per)
−300
300
450
−350
−450
350
450
ps
ps
7
7
Cumulative error across
n=11, 12,…49,50 cycles
tERR
(11-50per)
−450
Average high pulse width
Average low pulse width
Duty cycle jitter
tCH (avg)
tCL (avg)
tJIT (duty)
0.48
0.48
−100
0.52
0.52
100
0.48
0.48
−125
0.52
0.52
125
tCK (avg)
tCK (avg)
ps
2
3
4
Notes: 1. tCK (avg) is calculated as the average clock period across any consecutive 200cycle window.
N
tCK(avg) =
tCKj
N
∑
j =1
N = 200
2. tCH (avg) is defined as the average high pulse width, as calculated across any consecutive 200 high
pulses.
N
tCH(avg) =
tCHj (N ×tCK(avg))
∑
j =1
N = 200
3. tCL (avg) is defined as the average low pulse width, as calculated across any consecutive 200 low pulses.
N
tCL(avg) =
tCLj (N × tCK(avg))
∑
j =1
N = 200
4. tJIT (duty) is defined as the cumulative set of tCH jitter and tCL jitter. tCH jitter is the largest deviation of
any single tCH from tCH (avg). tCL jitter is the largest deviation of any single tCL from tCL (avg).
tJIT (duty) is not subject to production test.
tJIT (duty) = Min./Max. of {tJIT (CH), tJIT (CL)}, where:
tJIT (CH) = {tCHj- tCH (avg) where j = 1 to 200}
tJIT (CL) = {tCLj − tCL (avg) where j = 1 to 200}
5. tJIT (per) is defined as the largest deviation of any single tCK from tCK (avg).
tJIT (per) = Min./Max. of { tCKj − tCK (avg) where j = 1 to 200}
tJIT (per) defines the single period jitter when the DLL is already locked. tJIT (per, lck) uses the same
definition for single period jitter, during the DLL locking period only. tJIT (per) and tJIT (per, lck) are not
subject to production test.
Preliminary Data Sheet E1285E10 (Ver. 1.0)
24