Difference Between EEPROM and EPROM

EEPROM and EPROM are both types of programmable read-only memory (ROM). Both of them are nonvolatile memory which is used in computers to store the program. They both are external programming devices. Their memory can be erased and reprogrammed. EEPROM is an extended version of EPROM and EPROM is an extended version of PROM.


The main difference between EEPROM AND EPROM is that the content of EEPROM is erased by using electric signals while the content of EPROM is erased by UV Rays. EEPROM is a modern version of EPROM. Also, modern EEPROM allows multi-byte page operations. And takes less time to erase than EPROM.


EEPROM is a non-volatile memory. It is an extended version of EPROM that allows you to store your data, read and rewrite it. And therefore it has more features and is better than EPROM. EEPROM is usually used for multi-byte page operations. You can erase its content in milliseconds with the use of electric signals.

EPROM is an extended version of PROM. It is also non-volatile memory. It also allows you to rewrite data. Although it takes minutes to erase the data. The data is erased by exposing it to ultraviolet light. Mercury Vapor lamp being a source of UV light can be used for this purpose.

Comparison Table Between EEPROM And EPROM

Parameters of ComparisonEEPROMEPROM
What are they?Extended version of EPROM that allows storing data. It also allows rewriting programming.A type of ROM that allows rewriting data.
Programming TechniqueTunnel effect is used as the programming technique.Hot electron injection is used as the programming technique.
Erasing TechniqueElectric signals are used to erase its content.UV rays are used for erasing data.
Time Takes to EraseIt takes only milliseconds.It takes about 15 to 20 minutes.
Relative size of cellRelative size of the cell is three.The relative size of the cell is one.

What is EEPROM?

EEPROM which is also known as E2PROM stands for electrically erasable programmable read-only memory. It is a type of nonvolatile memory that is used in computers. In this type of form, the data stored can be retrieved easily. It is also used in integrated microcontrollers for electronic devices to store data.

Mostly it is used for security gadgets like Smart cards, remote keyless systems, Sim cards, Credit cards, etc. It allows the storage of relatively small amounts of data. It also allows individual bytes to be erased and reprogrammed again. It takes only seconds to erase the data. Electric signals are used in EEPROM to erase its content.

EEPROM requires a 2-transistor structure per bit to erase a byte in the memory. The transistor used in it doesn’t consume much voltage, it only consumes 5 volts. And the programming technique of EEPROM is the tunnel technique.

Small amounts of EEPROM are also used in products like real-time clocks, digital potentiometers, and digital temperature sensors, etc. However, there are limitations to this technology as well. The only two limitations are Data retention and endurance. For endurance, the maximum number can be 1 million. And 10 years are a limit for data retention.

Of the many advantages of EEPROM, one of them is that it doesn’t have to be taken out from the computer to erase the memory. 

What is EPROM?

EPROM stands for Erasable Programmable Read-Only Memory. It is an external programming integrated chip which is an extended version of PROM. It is a type of ROM that can be read and written optically. The EPROM is a chip that can retrieve the stored data. If the power supply goes this chip will retain its data. This way your data is safe.

EPROM has a rock crystal transparent window at the top through which the silicon chip is visible. EPROM has to be taken out of the computer to erase its memory. It has to be got off from the computer circuit to show it to the UV light source like a mercury vapor lamp, which will erase its memory. Different sources of UV light can take different times. It takes weeks to erase the memory from sunlight.

And then reprogramming the computer can be done. Additionally, the programming process of EPROM is not electrically reversible.Indeed, a programmed EPROM chip can retain its data for at least 10 to 20 years.

Hot electron injection programming is used for the programming of the EPROM. EPROM has a MOS transistor that takes up to 12.5 volts. Storing data in the memory requires applying a higher voltage to the transistors.

Main Differences Between EEPROM And EPROM

  1. The content of EEPROM is erased using an electric signal while on the other hand the content of EPROM is erased via UV rays.
  2. The relative size of cell in EEPROM is 3 while In EPROM is 1.
  3. EEPROM takes milliseconds to erase its content while EPROM takes minutes.
  4. EEPROM is an extended version of EPROM and therefore it has better features.
  5. The transistor used in EEPROM consumes only 5 volts while in EPROM it consumes 12.5 volts.
  6. EEPROM doesn’t have to be taken out from the computer to erase its memory while EPROM has to be taken out to erase the memory.


EEPROM and EPROM are both non-volatile memory that is used in computers and some electronic gadgets. EEPROM is the most modern version. Electric signals are used in EEPROM to erase the data and it takes only milliseconds. It has high speed and high density as well. Mostly it is used when small amounts of storage are there.

EPROM takes a much longer time to erase its content and its transistor uses more voltage well than EEPROM. Indeed, it uses UV light techniques to erase its content. In EPROM the silicon chip is visible on top of it. And so you have to take off the chip from the computer to erase its content.


  1. https://ieeexplore.ieee.org/abstract/document/200615/
  2. https://ieeexplore.ieee.org/abstract/document/1485793/
  3. https://ieeexplore.ieee.org/abstract/document/347410/
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