EtronTech
EM636165
1M x 16 SDRAM
6. A.C. Test Conditions
LVTTL Interface
Reference Level of Output Signals
Output Load
1.4V / 1.4V
Reference to the Under Output Load (B)
Input Signal Levels
2.4V / 0.4V
1ns
Transition Time (Rise and Fall) of Input Signals
Reference Level of Input Signals
1.4V
1.4V
3.3V
50W
1.2kW
50W
Z0=
Output
Output
30pF
30pF
870W
LVTTL D.C. Test Load (A)
LVTTL A.C. Test Load (B)
7. Transition times are measured between VIH and VIL. Transition(rise and fall) of input signals are in a fixed
slope (1 ns).
8. tHZ defines the time in which the outputs achieve the open circuit condition and are not at reference
levels.
9. These parameters account for the number of clock cycle and depend on the operating frequency of the
clock as follows:
the number of clock cycles = specified value of timing/Clock cycle time
(count fractions as a whole number)
10.If clock rising time is longer than 1 ns, ( tR / 2 -0.5) ns should be added to the parameter.
11.Assumed input rise and fall time tT ( tR & tF ) = 1 ns
If tR or tF is longer than 1 ns, transient time compensation should be considered, i.e., [(tr + tf)/2 - 1] ns
should be added to the parameter.
12. Power up Sequence
Power up must be performed in the following sequence.
1) Power must be applied to VDD and VDDQ(simultaneously) when all input signals are held "NOP" state
and both CKE = "H" and LDQM/UDQM = "H." The CLK signals must be started at the same time.
2) After power-up, a pause of 200mseconds minimum is required. Then, it is recommended that
LDQM/UDQM is held "HIGH" (VDD levels) to ensure DQ output is in high impedance.
3) Both banks must be precharged.
4) Mode Register Set command must be asserted to initialize the Mode register.
5) A minimum of 2 Auto-Refresh dummy cycles must be required before or after the Mode Register
Set command in step 4 to stabilize the internal circuitry of the device.
Preliminary
21
Rev. 2.7 Mar. 2006
ETRON [ ETRON TECHNOLOGY, INC. ]
