AS4C256K16FO Datasheet, PDF (1/25 Pages) Alliance Semiconductor Corporation – 5V 256K X 16 CMOS DRAM (Fast Page Mode)

AS4C256K16FO
®
5V 256K X 16 CMOS DRAM (Fast Page Mode)
Features
• Organization: 262,144 words × 16 bits
• High speed
- 25/30/35/50 ns RAS access time
- 12/16/18/25 ns column address access time
- 7/10/10/10 ns CAS access time
• Low power consumption
- Active: 770 mW max (ASAS4C256K16FO-50)
- Standby: 5.5 mW max, CMOS I/O
• Fast page mode
• AS4C256K16FO-50 timings are also valid for
AS4C256K16FO-60.
• 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
• Single 5V power supply/built-in V_bb generator
• Latch-up current > 200 mA
Pin arrangement
V_CC
I/O0
I/O1
I/O2
I/O3
I/VO^C4^C
I/O5
I/O6
I/O7
NC
NC
WE
RAS
NC
A0
A1
A2
A3
V_CC
SOJ
1
40
2
39
3
38
4
37
5
36
6
35
7
34
8
33
9
32
10
31
11
30
12
29
13
28
14
27
15
26
16
25
17
24
18
23
19
22
20
21
GND
I/O15
I/O14
V_CC
I/O0
I/O1
I/O13
I/O12
GND
I/O11
I/O2
I/O3
I/VO^C4^C
I/O10
I/O9
I/O8
I/O5
I/O6
I/O7
NC
LCAS
UCAS ^NC
OE ^NC
A8 WE
A7 RAS
A6 NC
A5
A0
A4
A1
GND A2
A3
V_CC
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
V_SS
I/O15
I/O14
I/O13
I/O12
VI/_{SOS 11}
I/O10
I/O9
I/O8
NC
LCAS
UCAS
OE
A8
A7
A6
A5
A4
V_SS
Pin designation
Pin(s)
A0 to A8
RAS
I/O0 to I/O15
OE
UCAS
LCAS
WE
V_CC
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 (+5V ± 10%)
Ground
Selection guide
Symbol
–25
–30
–35
–50
Unit
Maximum RAS access time
t_RAC
25
30
35
50
ns
Maximum column address
access time
t_CAA
12
16
18
25
ns
Maximum CAS access time
t_CAC
7
Maximum output enable (OE)
access time
t_OEA
7
10
10
10
10
10
ns
10
ns
Minimum read or write cycle
time
t_RC
40
65
70
85
ns
Minimum EDO page mode
cycle time
t_PC
12
12
14
25
ns
Maximum operating current I_CC1
200
180
160
140
mA
Maximum CMOS standby
current
I_CC2
2.0
2.0
2.0
2.0
mA
4/11/01; V.0.9.1
Alliance Semiconductor
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