H5PS1G83EFR View Datasheet(PDF) - Hynix Semiconductor

Part Name

Description

Manufacturer

H5PS1G83EFR

1Gb DDR2 SDRAM

Hynix Semiconductor 

Release

H5PS1G83EFR Series

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 DDR2-1066 SDRAM, the DRAM provides tQH of 575 ps

minimum.

2) If the system provides tHP of 900 ps into a DDR2-1066 SDRAM, the DRAM provides tQH of 650 ps min-

imum.

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.)

For example, 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(der-

ated) = 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. (Cau-

tion on the min/max usage!)

36. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tJIT(per) of

the input clock. (output deratings are relative to the SDRAM input clock.)

For example, if the measured jitter into a DDR2-1066 SDRAM has tJIT(per),min = - 72 ps and tJIT(per),max = + 63

ps, then tRPRE,min(derated) = tRPRE,min + tJIT(per),min = 0.9 x tCK(avg) - 72 ps = + 1615.5 ps and

tRPRE,max(derated) = tRPRE,max + tJIT(per),max = 1.1 x tCK(avg) + 63 ps = + 2125.5 ps. (Caution on the min/max

usage!)

37. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tJIT(duty) of

the input clock. (output deratings are relative to the SDRAM input clock.)

For example, if the measured jitter into a DDR2-1066 SDRAM has tJIT(duty),min = - 72 ps and tJIT(duty),max = + 63

ps, then tRPST,min(derated) = tRPST,min + tJIT(duty),min = 0.4 x tCK(avg) - 72 ps = + 678 ps and tRPST,max(der-

ated) = tRPST,max + tJIT(duty),max = 0.6 x tCK(avg) + 63 ps = + 1188 ps. (Caution on the min/max usage!)

Rev. 1.0 / Aug 2009

61

Share Link: