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AS4LC256K16EO Datasheet, PDF (1/25 Pages) Alliance Semiconductor Corporation – 3.3V 256K X 16 CMOS DRAM (EDO)
AS4LC256K16EO
®
3.3V 256K X 16 CMOS DRAM (EDO)
Features
• Organization: 262,144 words × 16 bits
• High speed
- 45/60 ns RAS access time
- 10/12/15/20 ns column address access time
- 7/10/10 ns CAS access time
• Low power consumption
- Active: 280 mW max (AS4LC256K16EO-35)
- Standby: 2.8 mW max, CMOS I/O (AS4LC256K16EO-
35)
• EDO page mode
• 5V I/O tolerant
• 512 refresh cycles, 8 ms refresh interval
- RAS-only or CAS-before-RAS refresh or self refresh
• Read-modify-write
• LVTTL-compatible, three-state I/O
• JEDEC standard packages
- 400 mil, 40-pin SOJ
- 400 mil, 40/44-pin TSOP II
• 3.3V power supply
• Latch-up current > 200 mA
Pin arrangement
SOJ
Vcc
1
40
I/O0
2
39
I/O1
3
38
I/O2
4
37
I/O3
5
36
Vcc
6
35
I/O4
7
34
I/O5
8
33
I/O6
9
32
I/O7
10
31
NC
11
30
NC
12
29
WE
13
28
RAS
14
27
NC
15
26
A0
16
25
A1
17
24
A2
18
23
A3
19
22
Vcc
20
21
GND
I/O15
I/O14
I/O13
I/O12
GND
I/O11
I/O10
I/O9
I/O8
NC
LCAS
UCAS
OE
A8
A7
A6
A5
A4
GND
VCC
I/O0
I/O1
I/O2
I/O3
VCC
I/O4
I/O5
I/O6
I/O7
NC
NC
WE
RAS
NC
A0
A1
A2
A3
VCC
TSOP II
1
44
2
43
3
42
4
41
5
40
6
39
7
38
8
37
9
36
10
35
13
32
14
31
15
30
16
29
17
28
18
27
19
26
20
25
21
24
22
23
GND
I/O15
I/O14
I/O13
I/O12
GND
I/O11
I/O10
I/O9
I/O8
NC
LCAS
UCAS
OE
A8
A7
A6
A5
A4
GND
Pin designation
Pin(s)
A0 to A8
RAS
I/O0 to I/O15
OE
UCAS
LCAS
WE
VCC
GND
Description
Address inputs
Row address strobe
Input/output
Output enable
Column address strobe, upper byte
Column address strobe, lower byte
Read/write control
Power (3.3V ± 0.3V)
Ground
Selection guide
Symbol AS4LC256K16EO-35 AS4LC256K16EO-45 AS4LC256K16EO-60 Unit
Maximum RAS access time
tRAC
35
45
Maximum column address access time
tCAA
17
20
Maximum CAS access time
tCAC
7
10
Maximum output enable (OE) access time tOEA
7
10
Minimum read or write cycle time
tRC
50
80
Minimum EDO page mode cycle time
tPC
15
17
Maximum operating current
ICC1
70
60
Maximum CMOS standby current
ICC2
200
200
60
ns
25
ns
10
ns
10
ns
100
ns
30
ns
50
mA
200
µA
4/11/01; V.1.1
Alliance Semiconductor
P. 1 of 25
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