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M87C257
ADDRESS LATCHED 256K (32K x 8) UV EPROM and OTP EPROM
INTEGRATED ADDRESS LATCH FAST ACCESS TIME: 45ns LOW POWER "CMOS" CONSUMPTION: - Active Current 30mA - Standby Current 100A PROGRAMMING VOLTAGE: 12.75V ELECTRONIC SIGNATURE for AUTOMATED PROGRAMMING PROGRAMMING TIMES of AROUND 3sec. (PRESTO II ALGORITHM)
28
1
FDIP28W (F)
PLCC32 (C)
Figure 1. Logic Diagram DESCRIPTION The M87C257 is a high speed 262,144 bit UV erasable and electrically programmable EPROM. The M87C257 incorporates latches for all address inputs to minimize chip count, reduce cost, and simplify the design of multiplexed bus systems. The Window Ceramic Frit-Seal Dual-in-Line package has a transparent lid which allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can then be written to the device by following the programming procedure. For applications where the content is programmed only one time and erasure is not required, the M87C257 is offered in Plastic Leaded Chip Carrier, package.
VCC
15 A0-A14
8 Q0-Q7
E G
M87C257
Table 1. Signal Names
A0 - A14 Q0 - Q7 E G ASVPP VCC VSS Address Inputs Data Outputs Chip Enable Output Enable Address Strobe / Program Supply Supply Voltage Ground
ASVPP
VSS
AI00928B
June 1996
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M87C257
Figure 2A. DIP Pin Connections
Figure 2B. LCC Pin Connections
Q1 Q2
AI00929
VSS DU Q3 Q4 Q5
AI00930
ASVPP A12 A7 A6 A5 A4 A3 A2 A1 A0 Q0 Q1 Q2 VSS
28 1 27 2 26 3 25 4 24 5 23 6 22 7 M87C257 21 8 20 9 19 10 18 11 17 12 13 16 14 15
VCC A14 A13 A8 A9 A11 G A10 E Q7 Q6 Q5 Q4 Q3
A7 A12 ASVPP DU VCC A14 A13 1 32 A6 A5 A4 A3 A2 A1 A0 NC Q0 A8 A9 A11 NC G A10 E Q7 Q6 9 M87C257 25 17
Warning: NC = Not Connected, DU = Dont't Use. Value -40 to 125 -50 to 125 -65 to 150 -2 to 7 -2 to 7 -2 to 13.5 -2 to 14
Table 2. Absolute Maximum Ratings (1)
Symbol TA TBIAS TSTG VIO
(2)
Parameter Ambient Operating Temperature Temperature Under Bias Storage Temperature Input or Output Voltages (except A9) Supply Voltage A9 Voltage Program Supply Voltage
Unit C C C V V V V
VCC VA9
(2)
VPP
Notes: 1. Except for the rating "Operating Temperature Range", stresses above those listed in the Table "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the SGS-THOMSON SURE Program and other relevant quality documents. 2. Minimum DC voltage on Input or Output is -0.5V with possible undershoot to -2.0V for a period less than 20ns. Maximum DC voltage on Output is VCC +0.5V with possible overshoot to VCC +2V for a period less than 20ns.
DEVICE OPERATION The modes of operation of the M87C257 are listed in the Operating Modes. A single power supply is required in the read mode. All inputs are TTL levels except for VPP and 12V on A9 for Electronic Signature.
Read Mode The M87C257 has two control functions, both of which must be logically active in order to obtain data at the outputs. Chip Enable (E) is the power control and should be used for device selection. Output Enable (G) is the output control and should
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M87C257
Table 3. Operating Modes
Mode Read (Latched Address) Read (Applied Address) Output Disable Program Verify Program Inhibit Standby Electronic Signature
Note: X = VIH or VIL, VID = 12V 0.5V
E VIL VIL VIL VIL Pulse VIH VIH VIH VIL
G VIL VIL VIH VIH VIL VIH X VIL
A9 X X X X X X X VID
ASVPP VIL VIH X VPP VPP VPP X VIL
Q0 - Q7 Data Out Data Out Hi-Z Data In Data Out Hi-Z Hi-Z Codes
Table 4. Electronic Signature
Identifier Manufacturer's Code Device Code A0 VIL VIH Q7 0 1 Q6 0 0 Q5 1 0 Q4 0 0 Q3 0 0 Q2 0 0 Q1 0 0 Q0 0 0 Hex Data 20h 80h
be used to gate data to the output pins, independent of device selection. Assuming that the addresses are stable (AS = VIH) or latched (AS = VIL), the address access time (tAVQV) is equal to the delay from E to output (tELQV). Data is available at the output after delay of tGLQV from the falling edge of G, assuming that E has been low and the addresses have been stable for at least tAVQV-tGLQV. The M87C257 reduces the hardware interface in multiplexed address-data bus systems. The processor multiplexed bus (AD0-AD7) may be tied to the M87C257's address and data pins. No separate address latch is needed because the M87C257 latches all address inputs when AS is low. Standby Mode The M87C257 has a standby mode which reduces the active current from 30mA to 100A (Address Stable). The M87C257 is placed in the standby mode by applying a CMOS high signal to the E input. When in the standby mode, the outputs are in a high impedance state, independent of the G input.
Two Line Output Control Because EPROMs are usually used in larger memory arrays, this product features a 2 line control function which accommodates the use of multiple memory connection. The two line control function allows: a. the lowest possible memory power dissipation, b. complete assurance that output bus contention will not occur. For the most efficient use of these two control lines, E should be decoded and used as the primary device selecting function, while G should be made a common connection to all devices in the array and connected to the READ line from the system control bus. This ensures that all deselected memory devices are in their low power standby mode and that the output pins are only active when data is desired from a particular memory device.
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M87C257
Table 5. AC Measurement Conditions
High Speed Input Rise and Fall Times Input Pulse Voltages Input and Output Timing Ref. Voltages 10ns 0 to 3V 1.5V Standard 20ns 0.4V to 2.4V 0.8V and 2V
Figure 3. AC Testing Input Output Waveform
Figure 4. AC Testing Load Circuit
1.3V
High Speed 3V 1.5V 0V
DEVICE UNDER TEST 3.3k 1N914
Standard 2.4V 2.0V 0.8V
AI01822
OUT CL = 30pF or 100pF
0.4V
CL = 30pF for High Speed CL = 100pF for Standard CL includes JIG capacitance
AI01823
Table 6. Capacitance (1) (TA = 25 C, f = 1 MHz )
Symbol CIN COUT Parameter Input Capacitance Output Capacitance Test Condition VIN = 0V VOUT = 0V Min Max 6 12 Unit pF pF
Note: 1. Sampled only, not 100% tested.
System Considerations The power switching characteristics of Advance CMOS 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 transient current peaks that are produced by the falling and rising edges of E. The magnitude of this transient current peaks is dependent on the capacitive and inductive loading of the device at the output. The associated transient voltage peaks can be suppressed by complying with the two line
output control and by properly selected decoupling capacitors. It is recommended that a 0.1F ceramic capacitor be used on every device between VCC and VSS. This should be a high frequency capacitor of low inherent inductance and should be placed as close to the device as possible. In addition, a 4.7F bulk electrolytic capacitor should be used between VCC and VSS for every eight devices. The bulk capacitor should be located near the power supply connection point. The purpose of the bulk capacitor is to overcome the voltage drop caused by the inductive effects of PCB traces.
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M87C257
Table 7. Read Mode DC Characteristics (1) (TA = 0 to 70C, -40 to 85C, -40 to 105C or -40 to 125C; VCC = 5V 5% or 5V 10%; VPP = VCC)
Symbol ILI ILO ICC ICC1 Parameter Input Leakage Current Output Leakage Current Supply Current Supply Current (Standby) TTL Test Condition 0V VIN VCC 0V VOUT VCC E = VIL, G = VIL, IOUT = 0mA, f = 5MHz E = VIH, ASVPP = VIH, Address Switching E = VIH, ASVPP = VIL, Address Stable E VCC - 0.2V, ASVPP VCC - 0.2V, Address Switching E VCC - 0.2V, ASVPP = VSS, Address Stable VPP = VCC -0.3 2 IOL = 2.1mA IOH = -1mA VCC - 0.8V Min Max 10 10 30 10 1 6 100 100 0.8 VCC + 1 0.4 Unit A A mA mA mA mA A A V V V V
ICC2
Supply Current (Standby) CMOS
IPP VIL VIH
(2)
Program Current Input Low Voltage Input High Voltage Output Low Voltage Output High Voltage
VOL VOH
Notes: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP. 2. Maximum DC voltage on Output is VCC +0.5V.
Table 8A. Read Mode AC Characteristics (1) (TA = 0 to 70C, -40 to 85C, -40 to 105C or -40 to 125C; VCC = 5V 5% or 5V 10%; VPP = VCC)
Symbol Alt Parameter Address Valid to Output Valid Address Valid to Address Strobe Low Address Strobe High to Address Strobe Low Address Strobe Low to Address Transition Address Strobe Low to Output Enable Low Chip Enable Low to Output Valid Output Enable Low to Output Valid Chip Enable High to Output Hi-Z Output Enable High to Output Hi-Z Address Transition to Output Transition G = VIL E = VIL G = VIL E = VIL E = VIL, G = VIL 0 0 0 Test Condition E = VIL, G = VIL 7 35 20 20 45 25 25 25 0 0 0 M87C257 -45 (3) -60 -70 -80 Unit Min Max Min Max Min Max Min Max tAVQV tAVASL tASHASL tASLAX tASLGL tELQV tGLQV tEHQZ
(2)
tACC tAL tLL tLA tLOE tCE tOE tDF tDF tOH
45 7
60 7 35 20 20 60 30 30 30 0 0 0 35 20 20
70 7 35 20 20 70 35 30 30 0 0 0
80
ns ns ns ns ns
80 40 40 40
ns ns ns ns ns
tGHQZ (2) tAXQX
Notes: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP. 2. Sampled only, not 100% tested. 3. In case of 45ns speed see High Speed AC measurement conditions.
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M87C257
Table 8B. Read Mode AC Characteristics (1) (TA = 0 to 70C, -40 to 85C, -40 to 105C or -40 to 125C; VCC = 5V 5% or 5V 10%; VPP = VCC)
Symbol Alt Parameter Test Condition M87C257 -90 -10 -12 -15/-20 Unit Min Max Min Max Min Max Min Max tAVQV tAVASL tASHASL tASLAX tASLGL tELQV tGLQV tEHQZ (2) tGHQZ
(2)
tACC tAL tLL tLA tLOE tCE tOE tDF tDF tOH
Address Valid to Output Valid Address Valid to Address Strobe Low Address Strobe High to Address Strobe Low Address Strobe Low to Address Transition Address Strobe Low to Output Enable Low Chip Enable Low to Output Valid Output Enable Low to Output Valid Chip Enable High to Output Hi-Z Output Enable High to Output Hi-Z Address Transition to Output Transition
E = VIL, G = VIL 7 35 20 20 G = VIL E = VIL G = VIL E = VIL E = VIL, G = VIL 0 0 0
90 7 35 20 20 90 40 40 40 0 0 0
100 7 35 20 20 100 40 30 30 0 0 0
120 7 35 20 20 120 50 40 40 0 0 0
150
ns ns ns ns ns
150 60 40 40
ns ns ns ns ns
tAXQX
Notes: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP. 2. Sampled only, not 100% tested.
Figure 5. Read Mode AC Waveforms
A0-A14 VALID tASLAX tAVASL ASVPP tASHASL tASLGL tAVQV E tGLQV G tELQV Q0-Q7 DATA OUT
AI00931
tAXQX
tEHQZ
tGHQZ Hi-Z
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M87C257
Table 9. Programming Mode DC Characteristics (1) (TA = 25 C; VCC = 6.25V 0.25V; VPP = 12.75V 0.25V)
Symbol ILI ICC IPP VIL VIH VOL VOH VID Parameter Input Leakage Current Supply Current Program Current Input Low Voltage Input High Voltage Output Low Voltage Output High Voltage TTL A9 Voltage IOL = 2.1mA IOH = -1mA VCC -0.8V 11.5 12.5 E = VIL -0.3 2 Test Condition VIL VIN VIH Min Max 10 50 50 0.8 VCC + 0.5 0.4 Unit A mA mA V V V V V
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP.
Table 10. Programming Mode AC Characteristics (1) (TA = 25 C; VCC = 6.25V 0.25V; VPP = 12.75V 0.25V)
Symbol tAVEL tQVEL tVPHEL tVCHEL tELEH tEHQX tQXGL tGLQV tGHQZ tGHAX Alt tAS tDS tVPS tVCS tPW tDH tOES tOE tDFP tAH Parameter Address Valid to Chip Enable Low Input Valid to Chip Enable Low VPP High to Chip Enable Low VCC High to Chip Enable Low Chip Enable Program Pulse Width Chip Enable High to Input Transition Input Transition to Output Enable Low Output Enable Low to Output Valid Output Enable High to Output Hi-Z Output Enable High to Address Transition 0 0 Test Condition Min 2 2 2 2 95 2 2 100 130 105 Max Unit s s s s s s s ns ns ns
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP
Programming When delivered (and after each erasure for UV EPROM), all bits of the M87C257 are in the "1" 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 present in the data word. The only way to
change a "0" to a "1" is by die exposition to ultraviolet light (UV EPROM). The M87C257 is in the programming mode when VPP input is at 12.75V, G is at VIH and E is pulsed to VIL. The data to be programmed is applied to 8 bits in parallel to the data output pins. The levels required for the address and data inputs are TTL. VCC is specified to be 6.25 V 0.25 V.
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M87C257
Figure 6. Programming and Verify Modes AC Waveforms
A0-A14 tAVEL Q0-Q7 DATA IN tQVEL ASVPP tVPHEL VCC tVCHEL E tELEH G
VALID
DATA OUT tEHQX
tGLQV
tGHQZ
tGHAX
tQXGL
PROGRAM
VERIFY
AI00557
Figure 7. Programming Flowchart
VCC = 6.25V, VPP = 12.75V
n=0
E = 100s Pulse NO ++n = 25 YES NO VERIFY YES Last Addr NO ++ Addr
FAIL
YES CHECK ALL BYTES 1st: VCC = 6V 2nd: VCC = 4.2V
AI00760B
PRESTO II Programming Algorithm PRESTO II Programming Algorithm allows to program the whole array with a guaranteed margin, in a typical time of 3.5 seconds. Programming with PRESTO II involves the application of a sequence of 100s program pulses to each byte until a correct verify occurs (see Figure 7). During programming and verify operation, a MARGIN MODE circuit is automatically activated in order to guarantee that each cell is programmed with enough margin. No overprogram pulse is applied since the verify in MARGIN MODE provides necessary margin to each programmed cell. Program Inhibit Programming of multiple M87C257s in parallel with different data is also easily accomplished. Except for E, all like inputs including G of the parallel M87C257 may be common. A TTL low level pulse applied to a M87C257's E input, with VPP at 12.75V, will program that M87C257. A high level E input inhibits the other M87C257s from being programmed. Program Verify A verify (read) should be performed on the programmed bits to determine that they were correctly programmed. The verify is accomplished with G at VIL, E at VIH, VPP at 12.75V and VCC at 6.25V.
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M87C257
Electronic Signature The Electronic Signature (ES) mode allows the reading out of a binary code from an EPROM that will identify its manufacturer and type. This mode is intended for use by programming equipment to automatically match the device to be programmed with its corresponding programming algorithm. The ES mode is functional in the 25C 5C ambient temperature range that is required when programming the M87C257. To activate the ES mode, the programming equipment must force 11.5V to 12.5V on address line A9 of the M87C257, with VCC = VPP = 5V. Two identifier bytes may then be sequenced from the device outputs by toggling address line A0 from V IL to VIH. All other address lines must be held at VIL during Electronic Signature mode. Byte 0 (A0=VIL) represents the manufacturer code and byte 1 (A0=VIH) the device identifier code. When A9 = VID, AS need not be toggled to latch each identifier address. For the SGS-THOMSON M87C257, these two identifier bytes are given in Table 4 and can be read-out on outputs Q0 to Q7. ERASURE OPERATION (applies for UV EPROM) The erasure characteristics of the M87C257 is such that erasure begins when the cells are exposed to light with wavelengths shorter than approximately 4000 A. It should be noted that sunlight and some type of fluorescent lamps have wavelengths in the 3000-4000 A range. Research shows that constant exposure to room level fluorescent lighting could erase a typical M87C257 in about 3 years, while it would take approximately 1 week to cause erasure when exposed to direct sunlight. If the M87C257 is to be exposed to these types of lighting conditions for extended periods of time, it is suggested that opaque labels be put over the M87C257 window to prevent unintentional erasure. The recommended erasure procedure for the M87C257 is exposure to short wave ultraviolet light which has wavelength 2537A. The integrated dose (i.e. UV intensity x exposure time) for erasure should be a minimum of 15 W-sec/cm2. The erasure time with this dosage is approximately 15 to 20 minutes using an ultraviolet lamp with 12000 W/cm2 power rating. The M87C257 should be placed within 2.5 cm (1 inch) of the lamp tubes during the erasure. Some lamps have a filter on their tubes which should be removed before erasure.
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M87C257
ORDERING INFORMATION SCHEME Example: M87C257 -70 X C 1 X
Speed -45
(1)
VCC Tolerance X blank 5% 10% F C
Package FDIP28W PLCC32
Temperature Range 1 6 7 3 0 to 70 C -40 to 85 C -40 to 105 C -40 to 125 C TR X
Option Additional Burn-in Tape & Reel Packing
45 ns 60 ns 70 ns 80 ns 90 ns 100 ns 120 ns 150 ns 200 ns
-60 -70 -80 -90 -10 -12 -15 -20
Note: 1. High Speed, see AC Characteristics section for further information.
For a list of available options (Speed, VCC Tolerance, Package, etc...) refer to the current Memory Shortform catalogue. For further information on any aspect of this device, please contact the SGS-THOMSON Sales Office nearest to you.
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M87C257
FDIP28W - 28 pin Ceramic Frit-seal DIP, with window
Symb Typ A A1 A2 B B1 C D E E1 e1 e3 eA L S N
FDIP28W
mm Min Max 5.71 0.50 3.90 0.40 1.17 0.22 1.78 5.08 0.55 1.42 0.31 38.10 15.40 13.05 2.54 33.02 - - 16.17 3.18 1.52 7.11 - 4 28 15.80 13.36 - - 18.32 4.10 2.49 - 15 0.280 0.100 1.300 Typ
inches Min Max 0.225 0.020 0.154 0.016 0.046 0.009 0.070 0.200 0.022 0.056 0.012 1.500 0.606 0.514 - - 0.637 0.125 0.060 - 4 28 0.622 0.526 - - 0.721 0.161 0.098 - 15
A2 A1 B1 B e3 D S
N 1
A L eA C
e1
E1
E
FDIPW-a
Drawing is not to scale
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M87C257
PLCC32 - 32 lead Plastic Leaded Chip Carrier, rectangular
Symb Typ A A1 B B1 D D1 D2 E E1 E2 e N Nd Ne CP
PLCC32
mm Min 2.54 1.52 0.33 0.66 12.32 11.35 9.91 14.86 13.89 12.45 1.27 - 32 7 9 0.10 Max 3.56 2.41 0.53 0.81 12.57 11.56 10.92 15.11 14.10 13.46 - 0.050 Typ
inches Min 0.100 0.060 0.013 0.026 0.485 0.447 0.390 0.585 0.547 0.490 - 32 7 9 0.004 Max 0.140 0.095 0.021 0.032 0.495 0.455 0.430 0.595 0.555 0.530 -
D D1
1N
A1
B1
Ne
E1 E
D2/E2 B
e
Nd
A CP
PLCC
Drawing is not to scale
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M87C257
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics.
(c) 1996 SGS-THOMSON Microelectronics - All Rights Reserved
SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
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