Full text of “IC Datasheet: 27C EPROM Data Sheet” . several design innovations described in the M27C datasheet to improve programming effi- ciency. 27C Kilobit (64k X 8 Bit) CMOS EPROM. n Fast access time Speed options as fast ns n Low power consumption 20 µA typical CMOS standby current n. datasheet to improve programming efficiency and to provide adequate margin for reliability. Before starting the programming the internal MARGIN MODE circuit.
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Search the history of over billion web pages on the Internet. Datasneet text of ” IC Datasheet: Logic Diagram 4 Table 1. Signal Names 4 Figure 3. DIP Connections 5 Figure 4.
LCC Connections 5 Figure 5. Operating Modes 6 Table 3. AC Measurement Conditions 10 Figure 7. Testing Input Output Waveform 10 Figure 8.
Capacitance 10 Table 7. Package Outline 17 Table Package Mechanical Data 17 Figure Package Outline 19 Table It is ideally suited for applica- tions where fast turn-around and pattern experi- mentation are important requirements and is organized as by 8 bits.
The FDIP28W window ceramic frit-seal package has transparent lid which allows the user to ex- pose the chip to ultraviolet light to erase the bit pat- tern.
A new pattern can then be written to the device by following the programming 277c512. DIP Connections Figure 5. A single power supply is required in theread mode.
27C512 Datasheet PDF
Read Mode The M27C has two control functions, both of which must be logically active in order to obtain dataxheet 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 be used to gate data to the output pins, indepen- dent of device selection. The two line control function allows: For the most efficient use of these two control lines, E should be decoded and used as the prima- ry device selecting function, while G should be made a common connection to all d evices in the array and connected to the READ line from the system control bus.
This ensures that all deselect- ed memory devices are in their low power standby mode and that the output pins are only active when data is required from 2c512 particular memory device. Ice, has three seg- ments that are of interest to the system designer: The magnitude of the 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.
27C Datasheet PDF –
It is recommended that a 0. 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. Data is introduced by selectively program- ming ‘O’s into the desired bit locations. Although only ‘O’s will be programmed, both ‘1 ‘s and ‘O’s can be present in the data word.
The M27C is in the pro- g.
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 in- puts are TTL. Vqc is specified to be 6. This can be achieved with STMicroelectronics M27C due to several design innovations described in the M27C datasheet to improve programming effi- ciency and to provide adequate margin for reliabil- ity. Then a sequence of 1 00 is program pulses are ap- plied to each byte until a correct verify occurs.
Program Inhibit Programming of multiple M27Cs in parallel with different data is also easily accomplished. A high level E input inhibits the other M27C51 2s from being pro- grammed.
Program Verify A verify read should be performed on the pro- grammed bits to determine that they were correct ly programmed.
The verify is accomplished with G at V L. This mode is intended for use by programming equipment to automatically match the device to be programmed with its corresponding datasheey algorithm. To activate the ES mode, the programming equipment must force Two identifier bytes may then be se- quenced from the device outputs by toggling ad- dress line AO from Vil to Vih.
All other address lines must be held at Vil during Electronic Signa- ture mode.
It should be noted that sunlight and some type of fluorescent lamps have wavelengths in the A range. Research shows that constant exposure to room level fluorescent lighting could erase a typical M27C in about 3 years, while it would take ap- proximately 1 week to cause erasure when ex- posed to direct sunlight. If the M27C is to be exposed to these types of lighting conditions for extended periods of time, it is suggested that UV EPROM opaque labels be put over the M27C window to prevent unintentional erasure.
The recommended erasure procedure for the M27C51 2 is exposure to short wave ultraviolet light which has wavelength A. The integrated dose i. The M27C should be placed within 2.
Full text of “IC Datasheet: 27C EPROM Data Sheet”
Some lamps have a filter on their tubes which should be removed before erasure. These are stress ratings only, and operation of the device at these, or any other conditions out- side those indicated in the Operating sections of this specification, is not implied. Exposure to Ab- solute Maximum Rating conditions for extended periods may affect device reliability. Minimum DC voltage on Input or Output is The parameters in the DC and AC Characteristic tables that follow are de- rived from tests performed under the Measure- ment Conditions summarized in the relevant tables.
Designers should check that the operating conditions in their 27d512 match datashewt measurement dahasheet when relying on the quoted parame- ters. Vcc must be applied simultaneously with or before Vpp and removed simultaneously or after Vpp. Speed obtained with High Speed AC measurement conditions. Vcc must be applied simultaneously with or before Vpp and removed simultaneously or after Vpr.
Drawing is not to scaie. Drawing is not to scaie Table Ordering Information Scheme Example: High Speed, see AC Characteristics section for further information. For a list of available options speed, package, device, please contact your nearest ST Sales Of- etc. However, STMicroelectronics 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 othenwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.