MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Order this document
by MCM6708A/D
64K x 4 Bit Static RAM
The MCM6708A is a 262,144 bit static random access memory organized as
65,536 words of 4 bits, fabricated using high–performance silicon–gate BiCMOS
technology. Static design eliminates the need for external clocks or timing
strobes.
The MCM6708A is available in a 300 mil, 24 lead plastic surface–mount SOJ
package.
•
•
•
•
•
Single 5 V
±
10% Power Supply
Fully Static — No Clock or Timing Strobes Necessary
All Inputs and Outputs are TTL Compatible
Three State Outputs
Fast Access Times:
MCM6708A–8 = 8 ns
MCM6708A–10 = 10 ns
MCM6708A–12 = 12 ns
MCM6708A
J PACKAGE
300 MIL SOJ
CASE 810A–02
PIN ASSIGNMENT
1
2
3
4
5
6
7
8
9
10
11
12
VCC
A15
A14
A13
A12
A11
A10
DQ0
DQ1
DQ2
DQ3
W
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
E
VSS
24
23
22
21
20
19
18
17
16
15
14
13
BLOCK DIAGRAM
A
A
A
A
A
A
A
A
ROW
DECODER
MEMORY MATRIX
256 ROWS x 256 x 4
COLUMNS
DQ0
•
•
•
DQ3
A
A
A
•
•
•
INPUT
DATA
CONTROL
COLUMN I/O
COLUMN DECODER
•
•
•
PIN NAMES
A0 – A15 . . . . . . . . . . . Address Inputs
W . . . . . . . . . . . . . . . . . . . Write Enable
E . . . . . . . . . . . . . . . . . . . . . Chip Enable
DQ0 – DQ3 . . . . . . . Data Input/Output
VCC . . . . . . . . . . . + 5 V Power Supply
VSS . . . . . . . . . . . . . . . . . . . . . . Ground
NC . . . . . . . . . . . . . . . . No Connection
A
A
A
A
A
E
W
REV 5
5/95
©
Motorola, Inc. 1995
MOTOROLA FAST SRAM
MCM6708A
2–1
TRUTH TABLE
(X = Don’t Care)
E
H
L
L
L
G
X
H
L
X
W
X
H
H
L
Mode
Not Selected
Read
Read
Write
Output
High–Z
High–Z
Dout
Din
Cycle
—
—
Read Cycle
Write Cycle
ABSOLUTE MAXIMUM RATINGS
(See Note)
Rating
Power Supply Voltage
Voltage Relative to VSS for Any Pin
Except VCC
Output Current (per I/O)
Power Dissipation
Temperature Under Bias
Operating Temperature
Storage Temperature — Plastic
Symbol
VCC
Vin, Vout
Iout
PD
Tbias
TA
Value
– 0.5 to + 7.0
– 0.5 to VCC + 0.5
±
30
2.0
– 10 to + 85
0 to + 70
Unit
V
V
mA
W
°C
°C
This device contains circuitry to protect the
inputs against damage due to high static volt-
ages or electric fields; however, it is advised
that normal precautions be taken to avoid appli-
cation of any voltage higher than maximum
rated voltages to this high–impedance circuit.
This BiCMOS memory circuit has been de-
signed to meet the dc and ac specifications
shown in the tables, after thermal equilibrium
has been established. The circuit is in a test
socket or mounted on a printed circuit board
and transverse air flow of at least 500 linear feet
per minute is maintained.
Tstg
– 55 to + 125
°C
NOTE: Permanent device damage may occur if ABSOLUTE MAXIMUM RATINGS are
exceeded. Functional operation should be restricted to RECOMMENDED OPER-
ATING CONDITIONS. Exposure to higher than recommended voltages for
extended periods of time could affect device reliability.
DC OPERATING CONDITIONS AND CHARACTERISTICS
(VCC = 5.0 V
±
10%, TA = 0 to 70°C, Unless Otherwise Noted)
RECOMMENDED OPERATING CONDITIONS
Parameter
Supply Voltage (Operating Voltage Range)
Input High Voltage
Input Low Voltage
Symbol
VCC
VIH
Min
4.5
2.2
Typ
5.0
—
—
Max
5.5
VCC + 0.3*
0.8
Unit
V
V
V
VIL
– 0.5**
* VIH (max) = VCC + 0.3 V dc; VIH (max) = VCC + 2.0 V ac (pulse width
≤
2.0 ns) or I
≤
30.0 mA.
** VIL (min) = – 0.5 V dc @ 30.0 mA; VIL (min) = – 2.0 V ac (pulse width
≤
2.0 ns) or I
≤
30.0 mA.
DC CHARACTERISTICS
Parameter
Input Leakage Current (All Inputs, Vin = 0 to VCC)
Output Leakage Current (E = VIH, Vout = 0 to VCC)
Output High Voltage (IOH = – 4.0 mA)
Output Low Voltage (IOL = 8.0 mA)
Symbol
Ilkg(I)
Ilkg(O)
VOH
VOL
Min
—
—
2.4
—
Max
±
1.0
±
1.0
—
0.4
Unit
µA
µA
V
V
POWER SUPPLY CURRENTS
Parameter
AC Active Supply Current (Iout = 0 mA, VCC = max,
f = fmax)
AC Standby Current (E = VIH, VCC = max, f = fmax)
CMOS Standby Current (VCC = max, f = 0 MHz,
E
≥
VCC – 0.2 V, Vin
≤
VSS, or
≥
VCC – 0.2 V)
Symbol
ICCA
ISB1
ISB2
MCM6708A–8
185
120
50
MCM6708A–10
175
110
50
MCM6708A–12
165
105
50
Unit
mA
mA
mA
Notes
1, 2, 3
1, 2, 3
NOTES:
1. Reference AC Operating Conditions and Characteristics for input and timing (VIH/VIL, tr/tf, pulse level 0 to 3.0 V, VIH = 3.0 V).
2. All addresses transition simultaneously low (LSB) and then high (MSB).
3. Data states are all zero.
MCM6708A
2–2
MOTOROLA FAST SRAM
CAPACITANCE
(f = 1.0 MHz, dV = 3.0 V, TA = 25°C, Periodically Sampled Rather Than 100% Tested)
Parameter
Address Input Capacitance
Control Pin Input Capacitance (E, G, W)
Input/Output Capacitance
Symbol
Cin
Cin
CI/O
Max
5
5
6
Unit
pF
pF
pF
AC OPERATING CONDITIONS AND CHARACTERISTICS
(VCC = 5.0 V
±
10%, TA = 0 to + 70°C, Unless Otherwise Noted)
Input Timing Measurement Reference Level . . . . . . . . . . . . . . . 1.5 V
Input Pulse Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 to 3.0 V
Input Rise/Fall Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ns
Output Timing Measurement Reference Level . . . . . . . . . . . . . 1.5 V
Output Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Figure 1A
READ CYCLES 1 AND 2
(See Notes 1 and 2)
MCM6708A–8
Parameter
Read Cycle Time
Address Access Time
Chip Enable Access Time
Output Hold from Address Change
Chip Enable Low to Output Active
Chip Enable High to Output High–Z
Symbol
tAVAV
tAVQV
tELQV
tAXQX
tELQX
tEHQZ
Min
8
—
—
3
1
0
Max
—
8
8
—
—
4.5
MCM6708A–10
Min
10
—
—
3
1
0
Max
—
10
10
—
—
5
MCM6708A–12
Min
12
—
—
3
1
0
Max
—
12
12
—
—
6
Unit
ns
ns
ns
ns
ns
ns
4, 5, 6
4, 5, 6
Notes
3
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
contention conditions during read and write cycles.
3. All read cycle timings are referenced from the last valid address to the first transitioning address.
4. At any given voltage and temperature, tEHQZ max is less than tELQX min for a given device and from device to device.
5. Transition is measured 200 mV from steady–state voltage with load of Figure 1B.
6. This parameter is sampled and not 100% tested.
AC TEST LOADS
+5 V
OUTPUT
Z0 = 50
Ω
RL = 50
Ω
VL = 1.5 V
OUTPUT
255
Ω
5 pF
480
Ω
TIMING LIMITS
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 (even though most devices do not
require it). On the other hand, responses from
the memory are specified from the device
point of view. Thus, the access time is shown
as a maximum since the device never pro-
vides data later than that time.
Figure 1A
Figure 1B
MOTOROLA FAST SRAM
MCM6708A
2–3
READ CYCLE 1
(See Note)
tAVAV
A (ADDRESS)
tAXQX
Q (DATA OUT)
PREVIOUS DATA VALID
tAVQV
NOTE: Device is continuously selected (E = VIL, G = VIL).
DATA VALID
READ CYCLE 2
(See Note)
tAVAV
A (ADDRESS)
tELQV
E (CHIP ENABLE)
tELQX
Q (DATA OUT)
tAVQV
NOTE: Addresses valid prior to or coincident with E going low.
DATA VALID
tEHQZ
MCM6708A
2–4
MOTOROLA FAST SRAM
WRITE CYCLE 1
(W Controlled, See Notes 1 and 2)
MCM6708A–8
Parameter
Write Cycle Time
Address Setup Time
Address Valid to End of Write
Write Pulse Width
Data Valid to End of Write
Data Hold Time
Write Low to Data High–Z
Write High to Output Active
Write Recovery Time
Symbol
tAVAV
tAVWL
tAVWH
tWLWH,
tWLEH
tDVWH
tWHDX
tWLQZ
tWHQX
tWHAX
Min
8
0
8
8
4
0
0
3
0
Max
—
—
—
—
—
—
4
—
—
MCM6708A–10
Min
10
0
9
9
5
0
0
3
0
Max
—
—
—
—
—
—
5
—
—
MCM6708A–12
Min
12
0
10
10
6
0
0
3
0
Max
—
—
—
—
—
—
6
—
—
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
4, 5, 6
4, 5, 6
Notes
3
NOTES:
1. A write occurs during the overlap of E low and W low.
2. Product sensitivities to noise require proper grounding and decoupling of power supplies as well as minimization or elimination of bus
contention conditions during read and write cycles.
3. All write cycle timing is referenced from the last valid address to the first transitioning address.
4. Transition is measured 200 mV from steady state voltage with load of Figure 1B.
5. This parameter is sampled and not 100% tested.
6. At any given voltage and temperature, tWLQZ max is less than tWHQX min both for a given device and from device to device.
WRITE CYCLE 1
tAVAV
A (ADDRESS)
tAVWH
E (CHIP ENABLE)
tWLWH
tWLEH
W (WRITE ENABLE)
tAVWL
D (DATA IN)
tWLQZ
Q (DATA OUT)
HIGH–Z
HIGH–Z
tDVWH
DATA VALID
tWHQX
tWHDX
tWHAX
MOTOROLA FAST SRAM
MCM6708A
2–5
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