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AS4C256K16E0 Datasheet, PDF (1/24 Pages) Alliance Semiconductor Corporation – 5V 256Kx16 CMOS DRAM (EDO)
AS4C256K16E0
®
5V 256K×16 CMOS DRAM (EDO)
Features
• Organization: 262,144 words × 16 bits
• High speed
- 30/35/50 ns RAS access time
- 16/18/25 ns column address access time
- 7/10/10/10 ns CAS access time
• Low power consumption
- Active: 500 mW max (AS4C256K16E0-25)
- Standby: 3.6 mW max, CMOS I/O (AS4C256K16E0-25)
• EDO page mode
• Refresh
- 512 refresh cycles, 8 ms refresh interval
- RAS-only or CAS-before-RAS refresh or self-refresh
- Self-refresh option is available for new generation device
only. Contact Alliance for more information.
• Read-modify-write
• TTL-compatible, three-state I/O
• JEDEC standard packages
- 400 mil, 40-pin SOJ
- 400 mil, 40/44-pin TSOP II
• 5V 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
TSOP II
GND
I/O15
I/O14
I/O13
I/O12
GND
I/O11
I/O10
I/O9
I/O8
VCC
1
I/O0 2
I/O1 3
I/O2 4
I/O3 5
VCC
6
I/O4 7
I/O5 8
I/O6 9
I/O7 10
NC
LCAS
UCAS
NC 13
OE
NC 14
A8
WE 15
A7
RAS 16
A6
NC 17
A5
A0 18
A4
A1 19
GND
A2 20
A3 21
VCC
22
44 GND
43 I/O15
42 I/O14
41 I/O13
40 I/O12
39 GND
38 I/O11
37 I/O10
36 I/O9
35 I/O8
32 NC
31 LCAS
30 UCAS
29 OE
28 A8
27 A7
26 A6
25 A5
24 A4
23 GND
Pin designation
Pin(s)
Description
A0 to A8
Address inputs
RAS
Row address strobe
I/O0 to I/O15 Input/output
OE
Output enable
UCAS
Column address strobe, upper byte
LCAS
Column address strobe, lower byte
WE
Read/write control
VCC
Power (5V ± 0.5V)
GND
Ground
Selection guide
Symbol AS4C256K16E0-30 AS4C256K16E0-35 AS4C256K16E0-50 Unit
Maximum RAS access time
tRAC
30
35
50
ns
Maximum column address access time
tCAA
16
18
25
ns
Maximum CAS access time
tCAC
10
10
10
ns
Maximum output enable (OE) access time tOEA
10
10
10
ns
Minimum read or write cycle time
tRC
65
70
85
ns
Minimum EDO page mode cycle time
tPC
12
14
25
ns
Maximum operating current
ICC1
180
160
140
mA
Maximum CMOS standby current
ICC2
2.0
2.0
2.0
mA
Shaded areas contain advance information.
4/11/01; v.1.1
Alliance Semiconductor
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