W971GG6JB
31. These parameters are specified per their average values, however it is understood that the following relationship between
the average timing and the absolute instantaneous timing holds at all times. (Min and max of SPEC values are to be used
for calculations in the table below.)
PARAMETER
Absolute clock period
Absolute clock HIGH pulse width
SYMBOL
tCK(abs)
tCH(abs)
MIN
tCK(avg),min + tJIT(per),min
tCH(avg),min x tCK(avg),min +
MAX
tCK(avg),max + tJIT(per),max
tCH(avg),max x tCK(avg),max +
UNIT
pS
pS
tJIT(duty),min
tJIT(duty),max
Absolute clock LOW pulse width
tCL(abs)
tCL(avg),min x tCK(avg),min +
tCL(avg),max x tCK(avg),max +
pS
tJIT(duty),min
tJIT(duty),max
Examples: 1) For DDR2-667, tCH(abs),min = (0.45 x 3000 pS ) - 125 pS = 1225 pS
2) For DDR2-1066, tCH(abs),min = (0.45 x 1875 pS ) - 75 pS = 768.75 pS
32. tHP is the minimum of the absolute half period of the actual input clock. tHP is an input parameter but not an input
specification parameter. It is used in conjunction with tQHS to derive the DRAM output timing tQH. The value to be used for
tQH calculation is determined by the following equation;
tHP = Min ( tCH(abs), tCL(abs) ),
where,
tCH(abs) is the minimum of the actual instantaneous clock HIGH time;
tCL(abs) is the minimum of the actual instantaneous clock LOW time;
33. tQHS accounts for:
1) The pulse duration distortion of on-chip clock circuits, which represents how well the actual tHP at the input is
transferred to the output; and
2) The worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next transition,
both of which are independent of each other, due to data pin skew, output pattern effects, and p-channel to n-
channel variation of the output drivers
34. tQH = tHP – tQHS, where:
tHP is the minimum of the absolute half period of the actual input clock; and
tQHS is the specification value under the max column.
{The less half-pulse width distortion present, the larger the tQH value is; and the larger the valid data eye will be.}
Examples:
1) If the system provides tHP of 1315 pS into a DDR2-667 SDRAM, the DRAM provides tQH of 975 pS minimum.
2) If the system provides tHP of 1420 pS into a DDR2-667 SDRAM, the DRAM provides tQH of 1080 pS minimum.
3) If the system provides tHP of 825 pS into a DDR2-1066 SDRAM, the DRAM provides tQH of 575 pS minimum.
4) If the system provides tHP of 900 pS into a DDR2-1066 SDRAM, the DRAM provides tQH of 650 pS minimum.
35. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tERR(6-10per) of the
input clock. (output deratings are relative to the SDRAM input clock.)
Examples:
1) If the measured jitter into a DDR2-667 SDRAM has tERR(6-10per),min = - 272 pS and tERR(6-10per),max = +
293 pS, then tDQSCK,min(derated) = tDQSCK,min - tERR(6-10per),max = - 400 pS - 293 pS = - 693 pS and
tDQSCK,max(derated) = tDQSCK,max - tERR(6-10per),min = 400 pS + 272 pS = + 672 pS.
Similarly, tLZ(DQ) for DDR2-667 derates to tLZ(DQ),min(derated) = - 900 pS - 293 pS = - 1193 pS and
tLZ(DQ),max(derated) = 450 pS + 272 pS = + 722 pS. (Caution on the min/max usage!)
2) If the measured jitter into a DDR2-1066 SDRAM has tERR(6-10per),min = - 202 pS and tERR(6-10per),max = +
223 pS, then tDQSCK,min(derated) = tDQSCK,min - tERR(6-10per),max = - 300 pS - 223 pS = - 523 pS and
tDQSCK,max(derated) = tDQSCK,max - tERR(6-10per),min = 300 pS + 202 pS = + 502 pS.
Similarly, tLZ(DQ) for DDR2-1066 derates to tLZ(DQ),min(derated) = - 700 pS - 223 pS = - 923 pS and
tLZ(DQ),max(derated) = 350 pS + 202 pS = + 552 pS. (Caution on the min/max usage!)
Publication Release Date: Sep. 24, 2013
- 53 -
Revision A09
相关PDF资料
W971GG8JB-25 IC DDR2 SDRAM 1GBIT 60WBGA
W9725G6IB-25 IC DDR2-800 SDRAM 256MB 84-WBGA
W9725G6JB25I IC DDR2 SDRAM 256MBIT 84WBGA
W9725G6KB-25I IC DDR2 SDRAM 256MBIT 84WBGA
W972GG6JB-3I IC DDR2 SDRAM 2GBITS 84WBGA
W9751G6IB-25 IC DDR2-800 SDRAM 512MB 84-WBGA
W9751G6KB-25 IC DDR2 SDRAM 512MBIT 84WBGA
W9812G6JH-6I IC SDRAM 128MBIT 54TSOPII
相关代理商/技术参数
W971GG6JB-25I 制造商:Winbond Electronics 功能描述:-40~85 1GB DDR2 FOR INDUSTRY
W971GG6JB25ITR 制造商:Winbond Electronics Corp 功能描述:1G, DDR2-800, X16, IND TEMP
W971GG6JB25TR 制造商:Winbond Electronics Corp 功能描述:NR, DDR2-800, X16
W971GG6JB-3 制造商:Winbond Electronics Corp 功能描述:1GBIT DDRII
W971GG6KB-18 制造商:Winbond Electronics Corp 功能描述:1G, DDR2-1066, X16 制造商:Winbond Electronics Corp 功能描述:IC MEMORY
W971GG8JB 制造商:WINBOND 制造商全称:Winbond 功能描述:16M × 8 BANKS × 8 BIT DDR2 SDRAM
W971GG8JB-25 功能描述:IC DDR2 SDRAM 1GBIT 60WBGA RoHS:是 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:72 系列:- 格式 - 存储器:RAM 存储器类型:SRAM - 同步 存储容量:4.5M(256K x 18) 速度:133MHz 接口:并联 电源电压:3.135 V ~ 3.465 V 工作温度:0°C ~ 70°C 封装/外壳:100-LQFP 供应商设备封装:100-TQFP(14x20) 包装:托盘
W9725G6IB-25 功能描述:IC DDR2-800 SDRAM 256MB 84-WBGA RoHS:是 类别:集成电路 (IC) >> 存储器 系列:- 标准包装:1,000 系列:- 格式 - 存储器:EEPROMs - 串行 存储器类型:EEPROM 存储容量:4K (512 x 8) 速度:400kHz 接口:I²C,2 线串口 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC(0.173",4.40mm 宽) 供应商设备封装:8-MFP 包装:带卷 (TR)