HYB39S256400DT Datasheet, PDF (20/22 Pages) Infineon Technologies AG – 256 MBit Synchronous DRAM

HYB39S256400/800/160DT(L)/DC(L)
256MBit Synchronous DRAM
Notes
1. For proper power-up see the operation section of this data sheet.
2. AC timing tests for LV-TTL versions have V_IL = 0.4 V and V_IH = 2.4 V with the timing referenced to
the 1.4 V crossover point. The transition time is measured between V_IH and V_IL. All AC
measurements assume t_T = 1 ns with the AC output load circuit shown in figure below. Specified
t_AC and t_OH parameters are measured with a 50 pF only, without any resistive termination and
with an input signal of 1V / ns edge rate between 0.8 V and 2.0 V.
C LOC K 1.4 V
tIH
tIS
t CH
2.4 V
0.4 V
tCL
t_T
INPUT
OUTPUT
1.4 V
tAC
tLZ
tA C
t OH
tHZ
1.4 V
IO.vsd
I/O
50 pF
Measurement conditions for
t_AC and t_OH
3. If clock rising time is longer than 1 ns, a time (t_T/2 − 0.5) ns has to be added to this parameter.
4. If t_T is longer than 1 ns, a time (t_T − 1) ns has to be added to this parameter.
5. These parameter account for the number of clock cycles and depend on the operating frequency
of the clock, as follows:
the number of clock cycles = specified value of timing period (counted in fractions as a whole
number)
6. Access time from clock t_AC is 4.6 ns for PC133 components with no termination and 0 pF load,
Data out hold time t_OH is 1.8 ns for PC133 components with no termination and 0 pF load.
7. It is recommended to use two clock cycles between the last data-in and the precharge command
in case of a write command without Auto-Precharge. One clock cycle between the last data-in
and the precharge command is also supported, but restricted to cycle times tck greater or equal
the specified twr value, where tck is equal to the actual system clock time
8. When a Write command with AutoPrecharge has been issued, a time of tdal(min) has be fullfilled
before the next Activate Command can be applied. For each of the terms, if not already an
integer, round up to the next highest integer. tck is equal to the actual system clock time.
INFINEON Technologies
20
2002-04-23