HM51W16165 Series, HM51W18165 Series
Self Refresh Mode (L-version)
HM51W16165L/HM51W18165L
-5
-6
-7
Parameter
Symbol Min
Max Min
Max Min
Max Unit
Notes
RAS pulse width (self refresh)
tRASS
100
—
100
—
100
—
µs
28, 29, 30,
31
RAS precharge time (self refresh) tRPS
CAS hold time (self refresh) tCHS
90
—
—
110
–50
—
—
130
–50
—
—
ns
ns
–50
Notes: 1. AC measurements assume tT = 2 ns.
2. An initial pause of 200 µs is required after power up followed by a minimum of eight initialization
cycles (any combination of cycles containing RAS-only refresh or CAS-before-RAS refresh).
3. Operation with the tRCD (max) limit insures that tRAC (max) can be met, tRCD (max) is specified as a
reference point only; if tRCD ≥ tRAD (max) + tAA (max) – tCAC (max), then access time is controlled
exclusively by tCAC
.
4. Operation with the tRAD (max) limit insures that tRAC (max) can be met, tRAD (max) is specified as a
reference point only; if tRAD is greater than the specified tRAD (max) limit, then access time is
controlled exclusively by tAA.
5. Either tOED or tCDD must be satisfied.
6. Either tDZO or tDZC must be satisfied.
7. VIH (min) and VIL (max) are reference levels for measuring timing of input signals. Also, transition
times are measured between VIH (min) and VIL (max).
8. Assumes that tRCD ≤ tRCD (max) and tRAD ≤ tRAD (max). If tRCD or tRAD is greater than the maximum
recommended value shown in this table, tRAC exceeds the value shown.
9. Measured with a load circuit equivalent to 1 TTL loads and 100 pF.
10. Assumes that tRCD ≥ tRCD (max) and tRCD + tCAC (max) ≥ tRAD + tAA (max).
11. Assumes that tRAD ≥ tRAD (max) and tRCD + tCAC (max) ≤ tRAD + tAA (max).
12. Either tRCH or tRRH must be satisfied for a read cycles.
13. tOFF (max) and tOEZ (max) define the time at which the outputs achieve the open circuit condition
and are not referred to output voltage levels.
14. tWCS, tRWD, tCWD, tAWD and tCPW are not restrictive operating parameters. They are included in the
data sheet as electrical characteristics only; if tWCS ≥ tWCS (min), the cycle is an early write cycle
and the data out pin will remain open circuit (high impedance) throughout the entire cycle; if tRWD
≥ tRWD (min), tCWD ≥ tCWD (min), and tAWD ≥ tAWD (min), or tCWD ≥ tCWD (min), tAWD ≥ tAWD (min) and tCPW
tCPW (min), the cycle is a read-modify-write and the data output will contain data read from the
selected cell; if neither of the above sets of conditions is satisfied, the condition of the data out
(at access time) is indeterminate.
≥
15. These parameters are referred to UCAS and LCAS leading edge in early write cycles and to WE
leading edge in delayed write or read-modify-write cycles.
16. tRASP defines RAS pulse width in EDO page mode cycles.
17. Access time is determined by the longest among tAA, tCAC and tCPA
.
18. In delayed write or read-modify-write cycles, OE must disable output buffer prior to applying data
to the device
19. When both UCAS and LCAS go low at the same time, all 16-bit data are written into the device.
UCAS and LCAS cannot be staggered within the same write/read cycles.
20 All the VCC and VSS pins shall be supplied with the same voltages.
Data Sheet E0153H10
15