MCM6246
3
MOTOROLA FAST SRAM
CAPACITANCE
(f = 1.0 MHz, dV = 3.0 V, TA = 25
°
C, Periodically Sampled Rather Than 100% Tested)
Parameter
Symbol
Typ
Max
Unit
Input Capacitance
All Inputs Except Clocks and DQs
E, G, W
Cin
Cck
4
5
6
8
pF
Input/Output Capacitance
DQ
CI/O
5
8
pF
AC OPERATING CONDITIONS AND CHARACTERISTICS
(VCC = 5.0 V
±
10%, TA = 0 to + 70
°
C, Unless Otherwise Noted)
Input Pulse Levels
Input Rise/Fall Time
Input Timing Measurement Reference Level
0 to 3.0 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 ns
1.5 V
. . . . . . . . . . . . . . .
Output Timing Measurement Reference Level
Output Load
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 V
. . . . . . . . . . . . .
See Figure 1
READ CYCLE TIMING
(See Note 1)
MCM6246–17
MCM6246–20
MCM6246–25
MCM6246–35
Parameter
Symbol
Min
Max
Min
Max
Min
Max
Min
Max
Unit
Notes
Read Cycle Time
tAVAV
tAVQV
tELQV
tGLQV
tAXQX
17
—
20
—
25
—
35
—
ns
2, 3
Address Access Time
—
17
—
20
—
25
—
35
ns
Enable Access Time
—
17
—
20
—
25
—
35
ns
4
Output Enable Access Time
—
6
—
6
—
8
—
10
ns
Output Hold from Address
Change
5
—
5
—
5
—
5
—
ns
Enable Low to Output Active
tELQX
tGLQX
5
—
5
—
5
—
5
—
ns
5, 6, 7
Output Enable Low to Output
Active
0
—
0
—
0
—
0
—
ns
5, 6, 7
Enable High to Output High–Z
tEHQZ
tGHQZ
—
8
—
8
—
10
—
12
ns
5, 6, 7
Output Enable High to Output
High–Z
—
8
—
8
—
10
—
12
ns
5, 6, 7
Power Up Time
tELICCH
tEHICCL
0
—
0
—
0
—
0
—
ns
Power Down Time
—
17
—
20
—
25
—
35
ns
NOTES:
1. W is high for read cycle.
2. Product sensitivities to noise require proper grounding and decoupling of power supplies as well as minimization or elimination of bus conten-
tion conditions during read and write cycles.
3. All read cycle timings are referenced from the last valid address to the first transitioning address.
4. Addresses valid prior to or coincident with E going low/E going high.
5. At any given voltage and temperature, tEHQZ max
tELQX min, and tGHQZ max
to device.
6. Transition is measured
±
500 mV from steady–state voltage.
7. This parameter is sampled and not 100% tested.
8. Device is continuously selected (E
≤
VIL, G
≤
VIL).
tGLQX min, both for a given device and from device
The table of timing values shows either a
minimum or a maximum limit for each param-
eter. Input requirements are specified from
the external system point of view. Thus, ad-
dress setup time is shown as a minimum
since the system must supply at least that
much time. On the other hand, responses
from the memory are specified from the de-
vice point of view. Thus, the access time is
shown as a maximum since the device never
provides data later than that time.
TIMING LIMITS
OUTPUT
Z0 = 50
RL = 50
VL = 1.5 V
Figure 1. AC Test Load