Holtek Semiconductor Inc HT23C040 Datasheet
Features
Operating voltage: 2.7V~5.5V
·
Low power consumption
·
–
Operation: 25mA max. (VCC=5V)
–
Standby: 30mA max. (VCC=5V)
Access time: 120ns max. (VCC=5V)
·
10mA max. (V
10mA max. (V
250ns max. (V
CC
CC
=3V)
CC
=3V)
=3V)
General Description
The HT23C040 is a read-only memory with
high performance CMOS storage device whose
4096K of memory is arranged into 524288 word
by 8 bits.
For application flexibility, the chip enable and
output enable control pins can be selected as ac
tive high or active low. This flexibility not only
allows easy interface with most microproces
sors, but also eliminates bus contention in mul
HT23C040
CMOS 512K´8-Bit Mask ROM
524288´8-bit of mask ROM
·
Mask option: chip enable CE/CE/OE1/OE1,
·
and output enable OE/OE
TTL compatible inputs and outputs
·
Tristate outputs
·
Fully static operation
·
Package type: 32-pin DIP/SOP
·
tiple bus microprocessor systems. An
additional feature of the HT23C040 is its abil
ity to enter the standby mode whenever the
chip enable (CE/CE
current consumption to below 30mA. The combi
nation of these functions makes the chip suit
able for high density low power memory
applications.
-
-
) is inactive, thus reducing
/NC
-
-
-
1 January 20, 2000
Block Diagram
HT23C040
A0
A18
CE/CE/OE1/O E1
OE/OE/NC
Pin Assignment
1
NC
A16
A15
A12
A7
A6
A5
A4
A3
A2
A1
A0
D0
D1
D2
VSS
32 D IP /S O P
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
HT23C040
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
Address
Buffers
CTRL
VCC
A18
A17
A14
A13
A8
A9
A11
OE/OE/NC
A10
CE/CE/OE1/O E1
D7
D6
D5
D4
D3
XY
Pre-decoder
ATD
Pre-charge C K T
Latch
X-Dec
Y-Dec
Z-D ec
VSS
Mux
VCC
Pull-high NM O S
ROM Cell
A rra y
(512K
8-Bits)
´
Z-se le ctor
S e n s e A m p lifie rs
Mux
Output Buffers
D0
D7
2 January 20, 2000
Pin Description
Pin Name I/O Description
NC
A0~A18 I Address inputs
D0~D7 O Data outputs
VSS
/OE1/OE1 I Chip enable/Output enable input
CE/CE
/NC I Output enable input
OE/OE
VCC
No connection
¾
Negative power supply
¾
Positive power supply
¾
Operation Truth Table
Mode CE/CE OE/OE A0~A18 D0~D7
Read H/L H/L Valid Data Out
Deselect H/L L/H X High Z
Standby L/H X X High Z
HT23C040
Note: H=VIH, L=VIL, X=VIHor V
IL
Absolute Maximum Ratings
Supply Voltage.................................-0.3V to 6V
Input Voltage .......................-0.3V to V
Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maxi-
mum Ratings² may cause substantial damage to the device. Functional operation of this device
at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.
CC
+0.3V
Storage Temperature.................-50°Cto125°C
Operating Temperature ..............-40°Cto85°C
3 January 20, 2000
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