HYB514171BJ-50- Datasheet, PDF (9/23 Pages) Siemens Semiconductor Group – 256k x 16-Bit Dynamic RAM

HYB 514171BJ-50/-60
256k × 16 DRAM
Notes
1. All voltages are referenced to V_SS.
2. I_CC, I_CC3, I_CC4 and I_CC6 depend on cycle rate.
3. I_CC1 and I_CC4 depend on output loading. Specified values are obtained with the output open.
4. Address can be changed once or less while RAS = V_IL. In case of I_CC4 it can be changed once
or less during a page mode cycle
5. An initial pause of 200 µs is required after power-up followed by 8 RAS cycles of which at least
one cycle has to be a refresh cycle, before proper device operation is achieved. In case of using
the internal refresh counter, a minimum of 8 CAS-before-RAS initialization cycles instead of 8
RAS cycles are required.
6. AC measurements assume t_T = 5 ns.
7. V_{IH (MIN.)} and V_{IL (MAX.)} are reference levels for measuring timing of input signals. Transition times
are also measured between V_IH and V_IL.
8. Measured with a load equivalent to 2 TTL loads and 100 pF.
9. Operation within the t_{RCD (MAX.)} limit ensures that t_{RAC (MAX.)} can be met. t_{RCD (MAX.)} is specified as
a reference point only. If t_RCD is greater than the specified t_{RCD (MAX.)} limit, then access time is
controlled by t_CAC.
10.Operation within the t_{RAD (MAX.)} limit ensures that t_{RAC (MAX.)} can be met. t_{RAD (MAX.)} is specified as
a reference point only. If t_RAD is greater than the specified t_{RAD (MAX.)} limit, then access time is
controlled by t_AA.
11.Either t_RCH or t_RRH must be satisfied for a read cycle.
12.t_{OFF (MAX.)}, t_{OEZ (MAX.)} define the time at which the output achieves the open-circuit conditions and
are not referenced to output voltage levels.
13.Either t_DZC or t_DZO must be satisfied.
14.Either t_CDD or t_ODD must be satisfied.
15.t_WCS, t_RWD, t_CWD and t_AWD are not restrictive operating parameters. They are included in the data
sheet as electrical characteristics only. If t_WCS > t_{WCS (MIN.)}, the cycle is an early write cycle and
data out pin will remain open-circuit (high impedance) through the entire cycle; if t_RWD > t_{RWD (MIN.)},
t_CWD > t_{CWD (MIN.)} and t_AWD > t_{AWD (MIN.)}, the cycle is a read-write cycle and I/O will contain data read
from the selected cells. If neither of the above sets of conditions is satisfied, the condition of I/O
(at access time) is indeterminate.
16.These parameters are referenced to the CAS leading edge in early write cycles and to the WE
leading edge in read-write cycles.
Semiconductor Group
9
1998-10-01