View NM27C240_117580.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
July 1998
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
General Description
The NM27C240 is a high performance Electrically Programmable UV erasable ROM (EPROM). It contains 4,194,304 bits configured as 256k x 16 bits. It is offered in both erasable versions for prototyping and early production applications as well as nonerasable, plastic packaged versions that are ideal for high volume and automated assembly applications. The NM27C240 operates from a single 5V 10% supply in the read mode. The NM27C240 is offered in both DIP and surface mount packages. The DIP package is a 40-pin dual-in-line ceramic with a quartz window to allow erasing. The surface mount package is a 44-pin PLCC that is offered in OTP. This EPROM is manufactured using Fairchild's proprietary AMGTM EPROM technology for an excellent combination of speed and economy while providing excellent reliability.
Features
s High performance CMOS -- 100 ns access time s Fast turn-off for microprocessor compatibility s Simplified upgrade path -- VPP and PGM are "Don't Care" during normal read operation s Compatible with 27240 and 27C240 EPROMs s JEDEC standard pin configuration -- 40-pin DIP package -- 44-pin PLCC package s Manufacturer's identification code s Fast programming algorithm
Block Diagram
Vcc GND Vpp OE CE/PGM Output Enable Chip Enable, and Program Logic Data Outputs O0 - O15
Output Buffers
Y Decoder A0 - A17 Address Inputs 4,194,304-Bit Cell Matrix X Decoder
DS011949-1
AMGTM is a trademark of WSI, Inc.
(c) 1998 Fairchild Semiconductor Corporation
1
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Connection Diagrams
DIP PIN CONFIGURATIONS
27C280 27C220 27C210
A18 CE/PGM O15 O14 O13 O12 O11 O10 O9 O8 GND O7 O6 O5 O4 O3 O2 O1 O0 OE/VPP XXVPP CE O15 O14 O13 O12 O11 O10 O9 O8 GND O7 O6 O5 O4 O3 O2 O1 O0 OE XXVPP CE O15 O14 O13 O12 O11 O10 O9 O8 GND O7 O6 O5 O4 O3 O2 O1 O0 OE XX/VPP CE/PGM O15 O14 O13 O12 O11 O10 O9 O8 GND O7 O6 O5 O4 O3 O2 O1 O0 OE
DIP NM27C240
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 VCC A17 A16 A15 A14 A13 A12 A11 A10 A9 GND A8 A7 A6 A5 A4 A3 A2 A1 A0
27C210 27C220 27C280
VCC XX/PGM NC A15 A14 A13 A12 A11 A10 A9 GND A8 A7 A6 A5 A4 A3 A2 A1 A0 VCC PGM A16 A15 A14 A13 A12 A11 A10 A9 GND A8 A7 A6 A5 A4 A3 A2 A1 A0 VCC A17 A16 A15 A14 A13 A12 A11 A10 A9 GND A8 A7 A6 A5 A4 A3 A2 A1 A0
DS011949-2
Note:
Compatible EPROM pin configurations are shown in the blocks adjacent to the NM27C240 pins.
Commercial Temperature Range
(0C to +70C) VCC = 5V 10% Parameter/Order Number
NM27C240 Q, V, N 100 NM27C240 Q, V, N 120 NM27C240 Q, V, N 150
Extended Temperature Range
(-40 to +85C) VCC = 5V 10% Parameter/Order Number
NM27C240 QE, VE, NE 120 NM27C240 QE, VE, NE 150
Access Time (ns)
100 120 150
Access Time (ns)
120 150
PLCC Pin Configuration
Package types: NM27C240 Q, V, N XXX Q = Quartz-Windowed Ceramic DIP Package V = PLCC Package N = Plastic DIP Package * All packages conform to JEDEC standard. * All versions are guaranteed to function in slower applications.
O13 O14 O15 CE/PGM XX/VPP NC VCC A17 A16 A15 A14
Note: Surface mount PLCC package available for commercial and extended temperature ranges only.
Pin Names
A0-A15 CE/PGM OE O0-O15 XX NC Addresses Chip Enable/Program Output Enable Outputs Don't Care (During Read) No Connect
O12 O11 O10 O9 O8 GND NC O7 O6 O5 O4
7
17
6 5 4 3 2 4443424140 1 8 38 9 37 10 36 11 35 12 34 13 33 14 32 15 31 16 30 181920212223242526 2728
O3 O2 O1 O0 OE NC A0 A1 A2 A3 A4
39
29
A13 A12 A11 A10 A9 GND NC A8 A7 A6 A5
Top View
DS011949-3
2
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Absolute Maximum Ratings (Note 1)
Storage Temperature All Input Voltages except A9 with Respect to Ground (Note 10) VPP and A9 with Respect to Ground VCC Supply Voltage with Respect to Ground ESD Protection All Output Voltages with Respect to Ground (Note 10) -65C to +150C -0.6V to +7V -0.6V to +14V -0.6V to +7V >2000V VCC + 1.0V to GND - 0.6V
Operating Range
Range
Commercial Industrial
Temperature
0C to +70C -40VC to +85C
VCC
+5V +5V
Tolerance
10% 10%
DC Read Characteristics Over Operating Range with VPP = VCC
Symbol
VIL VIH VOL VOH ISB1 ISB2 ICC IPP ILI ILO
Parameter
Input Low Level Input High Level Output Low Voltage Output High Voltage VCC Standby Current (CMOS) VCC Standby Current (TTL) VCC Active Current VPP Supply Current Input Load Current Output Leakage Current IOL = 2.1 mA
Conditions
Min
-0.5 2.0
Max
0.8 VCC +1 0.4
Units
V V V V
IOH = -2.5 mA CE = VCC 0.3V CE = VIH CE = OE = VIL, I/O = 0 mA VPP = VCC VIN = 5.5V or GND VOUT = 5.5V or GND f=5 MHz
3.5 100 1 40 10 -1 -10 1 10
A mA mA A A A
AC Read Characteristics Over Operating Range with VPP = VCC
Symbol
tACC tCE tOE tDF (Note 2) tOH (Note 2)
Parameter
Address to Output Delay CE to Output Delay OE to Output Delay Output Disable to Output Float Output Hold from Addresses CE or OE , Whichever Occurred First
100 Min Max
100 100 50 35 0
120 Min Max
120 120 50 35 0
150 Min Max
150 150 50 45 0
Units
ns
Capacitance TA = +25C, f = 1 MHz (Note 2)
Symbol
CIN COUT
Parameter
Input Capacitance Output Capacitance
Conditions
VIN = 0V VOUT = 0V
Typ
12 13
Max
20 20
Units
pF pF
3
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
AC Test Conditions
Output Load 1 TTL Gate and CL = 100 pF (Note 8) 5 ns 0.45V to 2.4V 0.8V and 2V 0.8V and 2V Input Rise and Fall Times Input Pulse Levels Timing Measurement Reference Level Inputs Outputs
AC Waveforms (Notes 6, 7) (Note 9)
Adresses 2.0V 0.8V Addresses Valid
CE
2.0V 0.8V tCE 2.0V 0.8V tOE Note 3 tDF Notes 4, 5 High Z tOH
DS011949-4
tCF Notes 4, 5
OE
Output
2.0V 0.8V
High Z tACC Note 3
Note 1: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 2: This parameter is only sampled and is not 100% tested. Note 3: OE may be delayed up to tACC -tOE after the falling edge of CE without impacting tACC. Note 4: The tDF and tCF compare level is determined as follows: High to TRI-STATE(R), the measured VOH1 (DC) - 0.10V; Low to TRI-STATE, the measured VOL1 (DC) + 0.10V. Note 5: TRI-STATE may be attained using OE or CE . Note 6: The power switching characteristics of EPROMs require careful device decoupling. It is recommended that at least a 0.1 F ceramic capacitor be used on every device between VCC and GND. Note 7: The outputs must be restricted to VCC + 1.0V to avoid latch-up and device damage. Note 8: 1 TTL Gate: IOL = 1.6 mA, IOH = -400 A. CL: 100 pF includes fixture capacitance. Note 9: VPP may be connected to VCC except during programming. Note 10: Inputs and outputs can undershoot to -2.0V for 20 ns Max.
4
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
DC Electrical Characteristics (Notes 11, 12, 13, 14)
Symbol
tAS tOES tDS tVPS tVCS tAH tDH tDF tPW tOE IPP ICC TA VCC VPP tFR VIL VIH tIN tOUT OE Setup Time Data Setup Time VPP Setup Time VCC Setup Time Address Hold Time Data Hold Time Output Enable to Output Float Delay Program Pulse Width Data Valid from OE VPP Supply Current during Programming Pulse VCC Supply Current Temperature Ambient Power Supply Voltage Programming Supply Voltage Input Rise, Fall Time Input Low Voltage Input High Voltage Input Timing Reference Voltage Output Timing Reference Voltage 2.4 0.8 0.8 20 6.25 12.5 5 0.0 4.0 2.0 2.0 0.45 25 6.5 12.75 CE = VIL CE = VIL, PGM = VIL CE = VIL
Parameter
Address Setup Time
Conditions
Min
1 1 1 1 1 0 1 0 45
Typ
Max
Units
s s
2.4
s s s s s
60 50 105 100 30 30 30 6.75 13.0
ns s ns mA mA C V V ns V V V V
Programming Waveforms (Note 13)
Program Adresses 2.0V 0.8V tAS Data 2.0V 0.8V tDS VCC 6.25V tVCS Data In Stable Add N tDH High Z Address N tAH Data Out Valid Add N tDF Program Verify
VPP
12.75V tVPS
CE/PGM
2.0V 0.8V tPW tOES tOE
OE
2.0V 0.8V
DS011949-5
Note 11: Fairchild's standard product warranty applies only to devices programmed to specifications described herein. Note 12: VCC must be applied simultaneously or before VPP and removed simultaneously or after VPP. The EPROM must not be inserted into or removed from a board with voltage applied to VPP or VCC. Note 13: The maximum absolute allowable voltage which may be applied to the VPP pin during programming is 14V. Care must be taken when switching the VPP supply to prevent any overshoot from exceeding this 14V maximum specification. At least a 0.1 F capacitor is required across VPP, VCC to GND to suppress spurious voltage transients which may damage the device. Note 14: During power up the CE/PGM pin must be brought high (VIH) either coincident with or before power is applied to VPP.
5
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Turbo Programming Algorithm Flow Chart
VCC = 6.5V VPP = 12.75V n=0 ADDRESS = FIRST LOCATION
PROGRAM ONE 50s PULSE INCREMENT n
NO
DEVICE FAILED
YES
n = 10?
FAIL
VERIFY BYTE
PASS
LAST ADDRESS ?
YES
NO
INCREMENT ADDRESS n=0
ADDRESS = FIRST LOCATION
VERIFY BYTE INCREMENT ADDRESS
NO PASS
FAIL
PROGRAM ONE 50 s PULSE
LAST ADDRESS ?
YES
CHECK ALL BYTES 1ST: VCC = VPP = 6.0V 2ND: VCC = VPP = 4.2V
DS011949-6 Note: The standard National Semiconductor algorithm may also be used but it will have longer programming time.
FIGURE 1.
6
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Functional Description
DEVICE OPERATION
The six modes of operation of the EPROM are listed in Table 1. It should be noted that all inputs for the six modes are at TTL levels. The power supplies required are VCC and VPP. VCC power supply must be at 12.75V during the three programming modes, and must be at 5V in the other three modes. The VCC power supply must be at 6.5V during the three programming modes, and at 5V in the other three modes.
dates this use of multiple connections. The 2-line control function allows for: 1. the lowest possible memory power dissipation, and 2. the complete assurance that output bus contention will not occur. To most efficiently use these two control lines, it is recommended that CE be decoded and used as the primary device selecting function, while OE be made a common connection to all devices in the array and connected to the READ line from the system control bus. This assures that all deselected memory devices are in their low power standby modes and that the output pins are active only when data is desired from a particular memory device.
Mode Selection
The modes of operation of the NM27C240 are listed in Table 1. A single 5V power supply is required in the read mode. All inputs are TTL levels except for VPP and A9 for device signature.
Programming
CAUTION: Exceeding 14V on the VPP or A9 pin will damage the EPROM. Initially, and after erasure, all bits of the EPROM are in the "1's" state. Data is introduced by selectively programming "0's" into the desired bit locations. Although only "0's" will be programmed, both "1's" and "0's" can be presented in the data word. The only way to change a "0" to a "1" is by ultraviolet light erasure. The EPROM is in the programming mode when the VPP power supply is at 12.75V and OE is at VIH. It is required that at least a 0.1 F capacitor be placed across VPP, VCC to ground to suppress spurious voltage transients which may damage the device. The data to be programmed is applied 16 bits in parallel to the data output pins. The levels required for the address and data inputs are TTL. When the address and data are stable, and active low, TTL program pulse is applied to the PGM input. A program pulse must be applied at each address location to be programmed. The EPROM is programmed with the Turbo Programming Algorithm shown in Figure 1. Each Address is programmed with a series of 50 s pulses until it verifies good, up to a maximum of 10 pulses. Most memory cells will program with a single 50 s pulse. (The standard National Semiconductor algorithm may also be used but it will have longer programming time.) The EPROM must not be programmed with a DC signal applied to the PGM input. Programming multiple EPROM in parallel with the same data can be easily accomplished due to the simplicity of the programming requirements. Like inputs of the parallel EPROM may be connected together when they are programmed with the same data. A low level TTL pulse applied to the PGM input programs the paralleled EPROM.
TABLE 1. Modes Selection
Pins Mode Read Output Disable Standby Programming Program Verify Program Inhibit CE/ PGM VIL X VIH VIL VIL VIH VIL VIH X VIH VIL X X X X 12.75V 12.75V 12.75V 5.0V 5.0V 5.0V 6.25V 6.25V 6.25V DOUT High Z High Z DIN DOUT High Z OE VPP VCC Outputs
Note 15: X can be V IL or VIH.
Read Mode
The EPROM has two control functions, both of which must be logically active in order to obtain data at the outputs. Chip Enable (CE) is the power control and should be used for selection. Output Enable (OE) is the output control and should be used to gate data to the output pins, independent of the device selection. Assuming that the addresses are stable, address access time (tACC) is equal to the delay from CE to output (tCE). Data is available at the outputs tOE after falling edge of OE, assuming that CE has been low and addresses have been stable for at least tACC - tOE.
Standby Mode
The EPROM standby mode reduces the active power dissipation by over 99%, from 165 mW to 0.55 mW. The EPROM is placed in the standby mode by applying a CMOS high signal to the CE input. When in standby mode, the outputs are in a high impedance state, independent of the OE input.
Program Inhibit
Programming multiple EPROM's in parallel with different data is also easily accomplished. Except for CE all like inputs (including OE and PGM) of the parallel EPROM may be common. A TTL low level program pulse applied to an EPROM's PGM input with CE at VIL and VPP at 12.75V will program that EPROM. A TTL high level CE input inhibits the other EPROM's from being programmed.
Output Disable
The EPROM is placed in output disable by applying a TTL high signal to the OE input. When in output disable all circuitry is enabled, except the outputs are in a high impedance state (TRISTATE).
Program Verify
A verify should be performed on the programmed bits to determine whether they were correctly programmed. The verify may be performed with VPP at 12.75V. VPP must be at VCC, except during programming and program verify.
Output OR-Tying
Because the EPROM is usually used in larger memory arrays, Fairchild has provided a 2-line control function that accommo-
7
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Functional Description (Continued)
After Programming
Opaque labels should be placed over the EPROM window to prevent unintentional erasure. Covering the window will also prevent temporary functional failure due to the generation of photo currents.
2537A. The integrated dose (i.e., UV intensity x exposure time) for erasure should be minimum of 15W-sec/cm2. The EPROM should be placed within 1 inch of the lamp tubes during erasure. Some lamps have a filter on their tubes which should be removed before erasure. An erasure system should be calibrated periodically. The distance from lamp to device should be maintained at one inch. The erasure time increases as the square of the distance from the lamp (if distance is doubled the erasure time increases by factor of 4). Lamps lose intensity as they age. When a lamp is changed, the distance has changed, or the lamp has aged, the system should be checked to make sure full erasure is occurring. Incomplete erasure will cause symptoms that can be misleading. Programmers, components, and even system designs have been erroneously suspected when incomplete erasure was the problem.
Manufacturer's Identification Code
The EPROM has a manufacturer's identification code to aid in programming. When the device is inserted in an EPROM programmer socket, the programmer reads the code and then automatically calls up the specific programming algorithm for the part. This automatic programming control is only possible with programmers which have the capability of reading the code. The manufacturer's identification code, shown in Table 2, specifically identifies the manufacturer and device type. The code for the NM27C240 is "8FEE", where "8F" designates that it is made by Fairchild Semiconductor, and "EE" designates a 4 Megabit (256k x 16) part. The code is accessed by applying 12V 0.5% to address pin A9. Addresses A1-A8, A10-A15, and all control pins are held at VIL. Address pin A0 is held at VIL for the manufacturer's code, and held at VIH for the device code. The code is read on the lower eight data pins, O0-O7. Proper code access is only guaranteed at 25C 5C.
System Consideration
The power switching characteristics of EPROMs require careful decoupling of the devices. The supply current, ICC, has three segments that are of interest to the system designer: the standby current level, the active current level, and the transient current peaks that are produced by voltage transitions on input pins. The magnitude of these transient current peaks is dependent on the output capacitance loading of the device. The associated VCC transient voltage peaks can be suppressed by properly selected decoupling capacitors. It is recommended that at least a 0.1 F ceramic capacitor be used on every device between VCC and GND. This should be a high frequency capacitor of low inherent inductance. In addition, at least a 4.7 F bulk electrolytic capacitor should be used between VCC and GND for each eight devices. The bulk capacitor should be located near where the power supply is connected to the array. The purpose of the bulk capacitor is to overcome the voltage drop caused by the inductive effects of the PC board traces.
Erasure Characteristics
The erasure characteristics of the device are such that erasure begins to occur when exposed to light with wavelengths shorter than approximately 4000 Angstroms (A). It should be noted that sunlight and certain types of fluorescent lamps have wavelengths in the 3000A-4000A range. The recommended erasure procedure for the EPROM is exposure to short wave ultraviolet light which has a wavelength of
TABLE 2. Manufacturer's Identification Code Pins
Manufacturer Code Device Code
A0 (21)
VIL VIH
A9 (31)
12V 12V
O7 (12)
1 1
O6 (13)
0 1
O5 (14)
0 1
O4 (15)
0 0
O3 (16)
1 1
O2 (17)
1 1
O1 (18)
1 1
O0 (19)
1 0
Hex Data
8F EE
8
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Physical Dimensions inches (millimeters) unless otherwise noted
2.096 (53.24) MAX
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21
0.015 - 0.035 RAD (0.38 - 0.89)
0.610 (15.49) Max Glass
0.590 (14.99) Max Ceramic
0.030 - 0.055 (0.76 -1.40) RAD TYP
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
UV Window size and configuration determined by device size 0.010 [0.25] MAX
0.005 MIN [0.13] 0.0200.070 [0.51 -1.78]
Glass Sealant
0.180 [4.57] MAX
0.225 [5.72] MAX
86 94 TYP 0.125 - 0.200 [3.18 - 5.08] 0.90 - 0.110 [2.29 - 2.79] TYP 0.098 [2.49] MAX (Both Ends)
0.150 [3.81] MIN
0.040 [1.02] TYP
0.5900.620 [14.99 - 15.75] 0.180 [4.57] MAX 90- 100 0.008 - 0.012 [0.20 - 0.30]
0.625 - 0.710 [15.88 - 18.03]
40-Lead Ceramic Dual-In-Line Package (Q) Order Number NM27C240Qxxx Package Number J40BQ
0.650-0.656 [16.51-16.66] PIN 1 INDENT 5 7 1 44 40 39 0.026-0.032 [0.66-0.81] TYP 0.590-0630 TYP [14.99-16.00] 45X 0.045 [1.14] 0.013-0.021 [0.33-0.53] TYP 45 X 0.045 [1.14]
17 18 28
29 0.50 Typ [1.27] 0.500 Typ [12.70]
0.020 MIN TYP [0.51] 0.090-0.130 TYP [2.29-3.30] 0.165-0.180 TYP [4.19-4.57]
0.685-0.695 TYP [17.40-17.65]
44-Lead Plastic Chip Carrier (V) Order Number NM27C240Vxxx Package Number V44A
9
www.fairchildsemi.com
NM27C240 4,194,304-Bit (256k x 16) High Performance CMOS EPROM
Physical Dimensions inches (millimeters) unless otherwise noted
1.90 - 2.10 (48.26 - 53.34)
40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21
0.062 RAD (1.575)
0.490 - 0.550 (12.446 - 13.97)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PIN #1 IDENT
0.050 (1.270)
0.125-0.165 (3.175-4.191) 0.145-0.210 (3.683-5.334)
86 94 TYP 0.040 - 0.090 (1.016 - 2.286) 0.100 0.010 (2.540 0.254) 0.0.18 0.003 (0.457 0.076) 0.035 - 0.070 (0.889 - 1.778)
0.015 (0.381) MIN 0.125-0.150 (3.048-3.81)
0.580 (14.73) MIN 0.600-0.620 (15.240-15.748)
0.030 (0.762) MAX
955
0.0080.015 (0.2030.381)
40-Lead Plastic Molded Dual-In-Line (N) Order Number NM27C240Nxxx
Life Support Policy
Fairchild's products are not authorized for use as critical components in life support devices or systems without the express written approval of the President of Fairchild Semiconductor Corporation. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user.
Fairchild Semiconductor Americas Customer Response Center Tel. 1-888-522-5372 Fairchild Semiconductor Europe Fax: +44 (0) 1793-856858 Deutsch Tel: +49 (0) 8141-6102-0 English Tel: +44 (0) 1793-856856 Francais Tel: +33 (0) 1-6930-3696 Italiano Tel: +39 (0) 2-249111-1
2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
Fairchild Semiconductor Hong Kong 8/F, Room 808, Empire Centre 68 Mody Road, Tsimshatsui East Kowloon. Hong Kong Tel; +852-2722-8338 Fax: +852-2722-8383
Fairchild Semiconductor Japan Ltd. 4F, Natsume Bldg. 2-18-6, Yushima, Bunkyo-ku Tokyo, 113-0034 Japan Tel: 81-3-3818-8840 Fax: 81-3-3818-8841
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications.
10
www.fairchildsemi.com

▲Up To Search▲

Price & Availability of NM27C240

	To Download NM27C240 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .