M27128A STMICROELECTRONICS | Alldatasheet
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P Q0-Q7 VPPVCC M27128A G E VSS Figure 1. Logic Diagram
DESCRIPTION
The M27128A is a 131,072 bit UV erasable and electrically programmable memory EPROM. It is organized as 16,384 words by 8 bits. The M27128A is housed in a 28 Pin Window Ce- ramic Frit-Seal Dual-in-Line package. The trans- parent lid 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 follow- ing the programming procedure. A0 - A13 Address Inputs Q0 - Q7 Data Outputs E Chip Enable G Output Enable P Program VPP Program Supply VCC Supply Voltage VSS Ground Table 1. Signal Names
Figure 2. DIP Pin Connections may affect device reliability. Refer also to the SGS-THOMSON SURE Program and other relevant quality documents. Table 2. Absolute Maximum Ratings control and should be used for device selection. pendent of device selection. impedance state, independent of the G input.
from a particular memory device. EPROMs require careful decoupling of the devices. by the inductive effects of PCB traces. change a “0" to a ”1" is by ultraviolet light erasure. PP input is at 12.5V and E and P are at TTL low. for the address and data inputs are TTL. Table 3. Operating Modes Table 4. Electronic Signature
Notes:1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP .
- Sampled only, not 100% tested.
Table 7. Read Mode AC Characteristics (1) Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP . Table 6. Read Mode DC Characteristics (1)
Note: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP . Table 8. Programming Mode DC Characteristics (1) Notes: 1. VCC must be applied simultaneously with or before VPP and removed simultaneously or after VPP .
- The Initial Program Pulse width tolerance is 1 ms ± 5%.
- The length of the Over-program Pulse varies from 2.85 ms to 78.95 ms, depending on the multiplication value of the iteration counter.
- Sampled only, not 100% tested.
Table 9. Programming Mode AC Characteristics (1)
A verify should be performed on the programmed bits to determine that they were correctly pro- grammed. The verify is accomplished with G = VIL, E = VIL, P = VIH and VPP at 12.5V. Electronic Signature The Electronic Signature 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. This mode is functional in the25°C ± 5°C ambient temperature range that is required when program- ming the M27128A. To activate this mode, the programming equipment must force 11.5V to 12.5V on address line A9 of the M27128A. Two identifier bytes may then be se- quenced from the device outputs by toggling ad- dress 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 manufac- turer code and byte 1 (A0 = VIH) the device identifier code. For the SGS-THOMSON M27128A, these two identifier bytes are given below. ERASURE OPERATION (applies to UV EPROM) The erasure characteristic of the M27128A is such that erasure begins when the cells are exposed to light with wavelengths shorter than approximately 4000 Å. It should be noted that sunlight and some type of fluorescent lamps have wavelengths in the 3000-4000 Å range. Research shows that constant exposure to room level fluorescent lighting could erase a typical M27128A in about 3 years, while it would take approximately 1 week to cause erasure when exposed to direct sunlight. If the M27128A 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 M27128A window to prevent unintentional erasure. The recommended erasure procedure for the M27128A is exposure to short wave ultraviolet light which has wavelength 2537 Å. The integrated dose (i.e. UV intensity x exposure time) for erasure should be a minimum of 15 W-sec/cm 2. The erasure time with this dosage is approximately 15 to 20 minutes using an ultra- violet lamp with 12000 µW/cm 2 power rating. The M27128A should be placed within 2.5cm (1 inch) of the lamp tubes during the erasure. Some lamps have a filter on their tubes which should be re- moved before erasure. Speed and VCC Tolerance -2 200 ns, 5V ±5% blank 250 ns, 5V ± 5% -3 300 ns, 5V ± 5% -4 450 ns, 5V ± 5% -20 200 ns, 5V ± 10% -25 250 ns, 5V ± 10% -30 300 ns, 5V ± 10% Package F FDIP28W Temperature Range 1 0 to 70 °C 6 –40 to 85 °C Example: M27128A -2 F 1 ORDERING INFORMATION SCHEME 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 SGS-THOMSON Sales Office nearest to you. M27128A
A L B1 B e1 D S E1 E N Cα eA Symb mm inches Typ Min Max Typ Min Max A 5.71 0.225 A1 0.50 1.78 0.020 0.070 A2 3.90 5.08 0.154 0.200 B 0.40 0.55 0.016 0.022 B1 1.17 1.42 0.046 0.056 C 0.22 0.31 0.009 0.012 D 38.10 1.500 E 15.40 15.80 0.606 0.622 E1 13.05 13.36 0.514 0.526 eA 16.17 18.32 0.637 0.721 L 3.18 4.10 0.125 0.161 S 1.52 2.49 0.060 0.098 α 4° 15° 4° 15° N2 8 2 8 FDIP28W Drawing is not to scale FDIP28W - 28 pin Ceramic Frit-seal DIP , with window M27128A
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. © 1995 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. M27128A