Image Source: FreeImages
EPROM stands for Erasable Programmable Read-Only Memory.
It’s a special type of non-volatile computer memory that can be erased and reprogrammed.
The EPROM is a kind of programmable ROM (Read-only Memory) that can be programmed just once, after which it cannot be rewritten.
It is able to retain its data after the power supply has been switched off.
EPROM is a great solution for storing small amounts of data with high integrity requirements.
Are you building a device that will require the use of an EPROM integrated circuit?
Or do you want to buy EPROM IC for sale?
This is a perfect guide for you.
In this article, we will explain to you everything you need to know about EPROM IC.
- 1 Understanding how EPROM works
- 2 How is data stored in EPROM?
- 3 What makes up an EPROM?
- 4 The relationship between EPROM IC and microcontroller
- 5 EPROM generations
- 6 The Design and structure of an EPROM IC
- 7 Types of EPROM IC
- 8 How to program an EPROM IC?
- 9 Where to use an EPROM IC? Applications
- 10 EPROM Specs you should know
- 11 Other things to look for when buying EPROM IC
- 12 Choosing an EPROM IC manufacturer
- 13 Final words-Get that EPROM IC
Understanding how EPROM works
Now, let’s look at how and why an EPROM IC is able to execute its mandate.
An EPROM comprises of a set of floating-gate transistors embedded inside a silicon chip.
The transistors are arranged in such a way that they can be programmed with data by applying a high voltage to the floating gate.
The high voltage on the floating gate changes the threshold voltage of the transistor, thereby changing its conductivity.
The EPROM IC is designed in such a way that it can be erased by exposing it to strong UV light for about ten minutes.
This process of erasing is usually called programming or burning-in.
After the UV light has been shined on it, the EPROM can be reprogrammed to store another set of data.
It should be noted that this process can only be done once, after which you cannot change or rewrite back to its original state when you need to program it again.
How is data stored in EPROM?
An EPROM is made up of two parts:
The first part is the memory which stores the data.
The second part is the control circuit which controls the memory.
It also contains a power source and a decoder section.
The data stored in EPROMs is not like binary code but rather, it is stored in a more complex way such that it can be read out or written back by an external device such as a computer.
This type of data storage is called non-volatile memory because it retains its information even after the power has been switched off.
What makes up an EPROM?
An EPROM is constructed from a silicon chip (monolithic) with two main parts:
1) Gate Array: This part forms one side of the memory array and contains all control gates for reading and writing into memory cells.
2) Memory Array: This part forms the other side of the memory array and consists of a matrix of flash memory cells.
The relationship between EPROM IC and microcontroller
It is important to know that in most devices, EPROM and Microcontrollers work together.
The EPROM can be accessed by the microcontroller in the following manner:
The microcontroller sends a command to the EPROM to read or write data.
The EPROM receives the command and sends back an acknowledgment signal.
The microcontroller sends an address to the EPROM that it wants to read/write.
The EPROM will send back a signal indicating whether this address is valid or not, in which case the microcontroller will need to send another address. If the address is valid, the chip will start sending data signals (for reading) or enable/disable signals (for writing).
The data transmission between the EPROM and microcontroller is synchronous which means that there is a clock signal sent by both devices that governs how fast they communicate with each other. This clock signal also dictates when one device needs to send/receive its data signals.
The development and manufacturing of EPROM ICs can be classified into different generations.
The first generation is 1702 and these ICs were manufactured using the p-MOS technology. These are the most reliable EPROMs and can withstand up to 2000 erase/write cycles. The second generation is 1704 and these ICs were manufactured using both p-MOS and n-MOS technology. The third generation is 2716 which uses a standard CMOS manufacturing process. It has the ability to be programmed more than 10,000 times. The fourth generation is 2732 which uses a standard CMOS manufacturing process. It has the ability to be programmed more than 100,000 times.
The first EPROMs were considered as an improvement over the EEPROMs because of their higher endurance (they could be erased and rewritten several thousand times).
They have been replaced by flash memory in most cases nowadays but they still find applications in some devices such as digital cameras, PDAs, and some portable music players where they are used as non-volatile RAM backup memory or for storing firmware upgrades (like on Archos players).
While the components from the different generations may be compatible, there are major differences in the programming capability and performance of these integrated circuits.
The Design and structure of an EPROM IC
The data is stored on the EPROM IC using electrical charges. This means that there is no physical change in the EPROM IC when data is stored on it.
To store data on an EPROM IC, electrical charges are put on its surface. To remove the data, these electrical charges are removed. This process is called erasing.
An EPROM IC has two layers of semiconductor material: a P-type silicon substrate and an N-type silicon oxide layer on top. The P-type silicon substrate is used to store the data.
The N-type silicon oxide layer is used to control the flow of electrons inside the chip. A small device called a diode is also placed next to the N-type layer.
The diode acts as a one-way gate for current flow. It allows current to flow from the N-type layer towards the P-type silicon substrate.
However, it does not allow the current to flow back from the P-type silicon substrate towards the N-type silicon oxide layer.
Types of EPROM IC
There are many different types of EPROMs used for various applications.
The EPROMs come in different types as per their usage, size, and requirements. The EPROMs are classified as
– UV-EROM: UV-EPROMs is the same as an EROM but can be reprogrammed using UV light. – EEPROM: Electrically Erasable Programmable Read-Only Memory is the same as an EPROM. It can be erased and reprogrammed using an electrical current, without any UV light.
– Flash: Flash EPROMs can be erased and programmed as many times as required. They are not meant for reprogramming as an EPROM. They are programmed only once, like an EPROM.
How to program an EPROM IC?
When you’re ready to program an EPROM IC, you’ll first need to get everything set up.
First, make sure the EPROM is installed in the correct direction.
The EPROM can be accessed by an external device using an EEPROM programmer:
The notch on the EPROM should match up with the notch on the IC socket.
Next, connect the programming equipment to the EPROM IC.
You need to select which memory addresses you want to write into using switches on the programmer’s front panel.
There are three leads on an EPROM: the address bus, data bus, and the control bus. The control bus is where the programming voltage is applied.
The programming voltage is applied to the control bus and the address bus.
The data bus is used to transfer data between the EPROM and the microcontroller.
The address bus is used to select which memory location you want to program.
The address bus is where you will put the data you wish to program into the EPROM.
– Finally, you need to apply the power supply to your board and program your circuit board by sending high voltage programming pulses from your programmer into it until programming is completed (usually takes less than a minute).
Where to use an EPROM IC? Applications
Image source Pinterest
The EPROM is mainly used to store a small amount of data with high integrity requirements.
The industries where the EPROM is used are
– Military: This industry deals with military hardware. Communication systems, navigation systems, and flight control systems are a few examples.
– Aerospace and Aviation: This industry deals with designing and manufacturing aircraft and spacecraft.
– Computers: This industry deals with designing and manufacturing computers and peripherals.
– Telecommunication: This industry deals with designing and manufacturing telecommunications hardware like telephone systems and radio systems.
– Healthcare: This industry deals with designing and manufacturing medical devices like surgical devices and blood transfusion devices.
What do you plan to use EPROM for? Let us know and we will get a perfect integrated circuit that will meet the exact needs of your application.
EPROM Specs you should know
When buying an EPROM IC, you should check out the following technical specifications.
They determine the overall performance, efficiency, and reliability of an EPROM:
-Operating current: This is the minimum current that is needed to keep the integrated circuit chip in full operation.
-Power dissipation: This is the total power consumption of the EPROM IC. It is usually measured in milliwatts.
– Erase/write cycle endurance – This is the number of times a programmed EPROM can be erased before the programming process becomes unreliable.
– Minimum write/erase time – This is the amount of time that is required to program or erase an EPROM.
– Programming voltage – This is the voltage that is applied to program an EPROM.
– Data retention – This is the length of time that programmed data will remain intact on an EPROM.
– Temperature range – This is the operating temperature range in which an EPROM will function.
-Screening levels: This is the level of radiation that can be expected to cause damage to an EPROM.
-Dose rate: This is the amount of radiation that can be expected to cause damage to an EPROM.
Other things to look for when buying EPROM IC
There are many different types of EPROMs available. When selecting an EPROM, keep these things in mind.
-Size of the EPROM IC: Usually the size is measured in terms of the number of ICs that can be placed on an 8″ x 11″ piece of paper.
-Package type: The package type is usually a plastic or ceramic IC package, with a metal lid, which has pins on it to connect the IC to other circuitry.
-Logic families of the EPROM: There are a number of logic families that are used to describe the logic levels of an EPROM. These families include Emitter Coupled Logic(ECL), CMOS, TTL, and LSTTL.
-Storage capacity of the EPROM: This is usually measured in terms of the number of bits that can be stored on an EPROM.
-Additional features: There are a number of additional features that may be available with an EPROM. These include a window for erasing the memory and a gold contact for better electrical conduction between the chip and other circuitry.
-Manufacturer: This is the company that made the EPROM IC. Ensure that the manufacturer or company is reputable and reliable. They should show the capacity and capability to deliver the best EPROM IC.
Choosing an EPROM IC manufacturer
When buying an EPROM IC, make sure you select the right manufacturer. This is very important because it determines the quality of the product and its lifetime.
A bad manufacturer may provide you with an EPROM IC of low quality and poor performance.
And where can I find a good EPROM IC manufacturer in China?
The best advice is to go through a sourcing agent.
Agents can do the sourcing and distribution of the ICs on your behalf.
This will allow you to focus on other core goals of the business such as production and testing.
Final words-Get that EPROM IC
The EPROM IC is a great piece of technology that has evolved over the years to be more efficient and reliable.
The EPROM IC is used to store a small amount of data with high integrity requirements.
We have discussed everything you need to know about this special type of IC. Now, it’s time to buy that EPROM IC and make your circuit work.
If you want to find more Electronic Components Distributors, please check out the following articles: