2764 SYC | Alldatasheet
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Technical content
P Q0-Q7 VPPVCC M27C64A G E VSS Figure 1. Logic Diagram
DESCRIPTION
The M27C64A is a high speed 65,536 bit UV eras- able and electrically programmable memory EPROM ideally suited for microprocessor systems requiring large programs. It is organized as 8,192 by 8 bits. The 28 pin Window Ceramic Frit-Seal Dual-in-Line package has transparent lid which allows the user to expose the chip to ultraviolet light to erase the bit pattern. Anew pattern can then be written to the device by following the programming procedure. For applications where the content is programmed only on time and erasure is not required, the M27C64A is offered in Plastic Leaded Chip Carrier package. A0 - A12 Address Inputs Q0 - Q7 Data Outputs E Chip Enable G Output Enable P Program V PP Program Supply VCC Supply Voltage VSS Ground Table 1. Signal Names
(tAVQV ) isequal to the delay from E tooutput (tELQV ). state, independent of the G input. is required from a particular memory device. by the inductive effects of PCB traces. Table 3. Operating Modes Table 4. Electronic Signature
Notes:1. VCC must be applied simultaneously with or before VPP and removed simultaneously with or after VPP.
- Sampled only, not 100% tested.
Table 7. Read Mode AC Characteristics(1) Notes:1. VCC must be applied simultaneously with or before VPP and removed simultaneous ly with or after VPP.
- Maximum DC voltage on Output is VCC +0.5V.
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.
- Sampled only, not 100% tested.
Table 9. Programming Mode AC Characteristics(1)
at 12.5V, will program that M27C64A. A high level E input inhibits the other M27C64A from being programmed. Program Verify A verify (read) should be performed on the pro- grammed bits to determine that they were correctly programmed. The verify is accomplished with E and G at V IL, P at VIH,VPP at 12.5V and VCC at 6V. 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 the 25°C ± 5°C ambient temperature range that is required when program- ming the M27C64A. To activate this mode, the programming equipmentmust force11.5Vto 12.5V on address line A9 of the M27C64A, with V PP =VCC =5V. Two identifier bytes may then be sequenced from the device outputs by toggling address line A0 from VIL to VIH. All other address lines must be held at VIL during Electronic Signa- ture mode. Byte 0 (A0=VIL) represents the manufacturer code and byte 1 (A0=VIH) the device identifier code. For the SGS-THOMSON M27C64A, these two identi- fier bytes are given in T able 4 and can be read-out on outputs Q0 to Q7. ERASURE OPERATION (applies to UV EPROM) The erasure characteristics of the M27C64A is such that erasure begins when the cells are ex- posed to light with wavelengths shorter than ap- proximately 4000Å. It should be noted that sunlight and some type of fluorescent lamps have wave- lengths in the 3000-4000 Å range. Research shows that constant exposure to room level fluo- rescent lighting could erase a typical M27C64A in about 3 years, while it would take approximately 1 week to cause erasure when exposed to direct sunlight. If the M27C64Ais to be exposed to these types of lighting conditions for extended periods of time, it is suggested that opaque labels be put over the M27C64Awindow to prevent unintentional era- sure. The recommended erasure procedure for the M27C64Ais exposure to short wave ultraviolet light which has a wavelength of 2537 Å. The inte- grated dose (i.e. UV intensity x exposure time) for erasure should be a minimum of 15 W-sec/cm The erasure time with this dosage is approximately 15 to 20 minutes using an ultraviolet lamp with 12000 uW/cm 2 powerrating. The M27C64Ashould be placed within 2.5 cm (1 inch) of the lamp tubes during the erasure. Some lamps have a filter on theirtubeswhich shouldbe removed beforeerasure. DEVICE OPERATIONS (cont’d) Speed -15 150 ns -20 200 ns -25 250 ns -30 300 ns Package F FDIP28W C PLCC32 Temperature Range 1 0 to 70 °C 6 –40 to 85 °C Option X Additional Burn-in TR Tape & Reel Packing Example: M27C64A -15 F 1 TR ORDERING INFORMATION SCHEME For a list of available options (Speed, 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. M27C64A
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 no to scale FDIP28W - 28 pin Ceramic Frit-seal DIP, with window M27C64A
PLCC32 - 32 lead Plastic Leaded Chip Carrier - rectangular PLCC D Ne E1 E Nd CP B D2/E2 e A Symb mm inches Typ Min Max Typ Min Max A 2.54 3.56 0.100 0.140 A1 1.52 2.41 0.060 0.095 B 0.33 0.53 0.013 0.021 B1 0.66 0.81 0.026 0.032 D 12.32 12.57 0.485 0.495 D1 11.35 11.56 0.447 0.455 D2 9.91 10.92 0.390 0.430 E 14.86 15.11 0.585 0.595 E1 13.89 14.10 0.547 0.555 E2 12.45 13.46 0.490 0.530 N3 2 3 2 Nd 7 7 Ne 9 9 CP 0.10 0.004 PLCC32 Drawing is no to scale M27C64A