315 December 12, 1997
UL6264A
p
Packages:PDIP28(600 mil)
SOP28 (330 mil)
Description
The UL6264A is a static RAM
manufactured using a CMOS pro-
cess technology with the following
operating modes:
- Read - Standby
- Write - Data Retention
The memory array is based on a
6-transistor cell.
The circuit is activated by the rising
edge of E2 (at E1 = L) or the falling
edge of E1 (at E2 = H). The
address and control inputs open
simultaneously. According to the
information of W and G the data
inputs, or outputs, are active. In the
active state E1 = L and E2 = H,
each address change leads to a
new Read or Write cycle. In a Read
cycle, the data outputs are activa-
ted by the falling edge of G, after-
wards the data word read will be
available at the outputs
DQ0 - DQ7. After the address
change, the data outputs go High-Z
until the new read information is
available. The data outputs have no
preferred state. If the memory is
driven by CMOS levels in the active
state, and if there is no change of
the address, data input and control
signals W or G, the operating cur-
rent (at IO = 0 mA) drops to the
value of the operating current in the
Standby mode. The Read cycle is
finished by the falling edge of E2 or
W, or by the rising edge of E1,
respectively.
Data retention is guaranteed down
to 2 V.
With the exception of E2, all inputs
consist of NOR gates, so that no
pull-up/pull-down resistors are
required. This gate circuit allows to
achieve low power standby require-
ments by activation with TTL-levels
too.
If the circuit is inactivated by E2 = L,
the standby current (TTL) drops to
100 µA typ.
Features
p
8192 x 8 bit static CMOS RAM
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250 and 500 ns Access Times
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Common data inputs and data
outputs
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Three-state outputs
p
Typ. operating supply current:
250ns:12 mA
500 ns: 7 mA
p
Standby current < 5 µA
p
Standby current at 25 °C
and 3.3 V: typ. 50 nA
p
TTL/CMOS-compatible
p
Automatic reduction of power
dissipation in long Read or Write
cycles
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Power supply voltage 3.3 V
p
Operating temperature ranges
0 to 70 °C
-25 to 85 °C
-40 to 85 °C
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Quality assessment according to
CECC 90000, CECC 90100 and
CECC 90111
p
ESD protection > 2000 V
(MIL STD 883C M3015.7)
p
Latch-up immunity > 100 mA
Low Voltage 8K x 8 SRAM
Pin Description
Signal Name Signal Description
A0 - A12 Address Inputs
DQ0 - DQ7 Data In/Out
E1 Chip Enable 1
E2 Chip Enable 2
GOutput Enable
WWrite Enable
VCC Power Supply Voltage
VSS Ground
n.c. not connected
Pin Configuration
1n.c. VCC28
2A12W (WE)27
4A6 A825
5A5 A924
3A7 E2 (CE2)26
6A4 A1123
7A3 G (OE)22
8A2 A1021
12DQ1DQ517
9A1 E (CE1)20
10A0 DQ719
11DQ0DQ618
13DQ2DQ416
14VSS DQ315
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