HYB18T512400B2C datasheet(57/69 Pages) QIMONDA

57 / 69 page

Internet Data Sheet

Rev. 1.12, 2007-05

10062006-YPTZ-CDR7

HY[B/I]18T512[40/80/16]0B2[C/F](L)

512-Mbit Double-Data-Rate-Two SDRAM

7.3

Jitter Definition and Clock Jitter Specification

Generally, jitter is defined as “the short-term variation of a signal with respect to its ideal position in time”. The following table

provides an overview of the terminology.

TABLE 49

Average Clock and Jitter Symbols and Definition

Symbol

Parameter

Description

Units

CK.AVG

Average clock period

CK.AVG is calculated as the average clock period within any consecutive

200-cycle window:

(1)

N=200

JIT.PER

Clock-period jitter

JIT.PER is defined as the largest deviation of any single tCK from tCK.AVG:

JIT.PER = Min/Max of {tCKi – tCK.AVG} where i = 1 to 200

JIT.PER defines the single-period jitter when the DLL is already locked.

JIT.PER is not guaranteed through final production testing.

JIT(PER, LCK)

Clock-period jitter

during DLL-locking

period

JIT(PER,LCK) uses the same definition as tJIT.PER, during the DLL-locking

period only.

JIT(PER,LCK) is not guaranteed through final production testing.

JIT.CC

Cycle-to-cycle clock

period jitter

JIT.CC is defined as the absolute difference in clock period between two

consecutive clock cycles:

JIT.CC = Max of ABS{tCKi+1 – tCKi}

JIT.CC defines the cycle- to- cycle jitter when the DLL is already locked.

JIT.CC is not guaranteed through final production testing.

JIT(CC, LCK)

Cycle-to-cycle clock

period jitter during

DLL-locking period

JIT(CC,LCK) uses the same definition as tJIT.CC during the DLL-locking

period only.

JIT(CC,LCK) is not guaranteed through final production testing.

ERR.2PER

Cumulative error

across 2 cycles

ERR.2PER is defined as the cumulative error across 2 consecutive cycles

from

CK.AVG:

(2)

n=2 for

ERR(2per)

where i = 1 to 200

tCK.AVG

----.

tCKj

∑

⎝⎠

⎜⎟

⎛⎞

tERR 2per

()

tCKj

in 1

–

∑

⎝⎠

⎜⎟

⎛⎞

ntCK avg

()

–

HYB18T512400B2C Scheda tecnica(PDF) 57 Page - Qimonda AG

HYB18T512400B2C Scheda tecnica(HTML) 57 Page - Qimonda AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69

Scheda tecnica Scarica

Link URL